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manlystanley
05-18-2010, 06:51 AM
I have my room conditioning on order now. I've ordered six 2X4 feet (4 inch thick Owens Corning 703 boards) from the below site. Then I have ordered swaths from www.sewbatik.com. I'm planning on building a frame and covering it with the batik. The batik has a low thread count ( less then 200), so it should be fairly transparent to both high and low frequencies.

http://www.atsacoustics.com/item--Owens-Corning-703-4-inch--1032.html

I've attached photos of my listening room (with my old 684's), but the rooms the same. What I have done to the room:

-- I filled the space above the rear cabinets with insulation. Then wrapped the insulation in some nice silk low thread count cloth. It is surprising how this little bit of room treatment has improved the sound.


What I'm planning on doing next:

-- First, I designed and built this room before I understood the importance for room treatments. So, the rear cabinets are in a terrible location. But, I'm stuck with them.

-- I have a bass reflection problem. In fact just by hanging insulation in the front corner and opening the door at the opposite side the room--it really improves the sound.

--So I'm planning on building two room treatments that will go in the front of the room and put them against the wall (please see attached drawing). I hoping that this will absorb the reflecteed bass, and generally improve the sound quality.


What do you guys think about this layout? From what I've read, this will improve the sound.


http://gallery.audioreview.com/showphoto.php?photo=6915&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6263&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6266&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6265&cat=500&ppuser=276367

JoeE SP9
05-18-2010, 07:14 AM
PC has recent experience building bass traps. He will probably be very helpful.

My suggestion is to dampen the first reflection points. To find them have someone move a mirror along the side walls while you're sitting in the listening position. When you can see the speaker in the mirror you have found the first reflection point. Place one of the fiberglass panels on the wall at that spot.

atomicAdam
05-18-2010, 08:11 AM
PC has recent experience building bass traps. He will probably be very helpful.

My suggestion is to dampen the first reflection points. To find them have someone move a mirror along the side walls while you're sitting in the listening position. When you can see the speaker in the mirror you have found the first reflection point. Place one of the fiberglass panels on the wall at that spot.

That would be my suggestion as well. HomeDepot has 8x4ft fiber boards for $10. I've been using them to dampen the 1st reflection points and the rear wall and I am well happy with the result.

I found the board in the insolation section of HD. They are a dark drown, so a cover is a good idea.

Sir Terrence the Terrible
05-18-2010, 09:42 AM
PC has recent experience building bass traps. He will probably be very helpful.

My suggestion is to dampen the first reflection points. To find them have someone move a mirror along the side walls while you're sitting in the listening position. When you can see the speaker in the mirror you have found the first reflection point. Place one of the fiberglass panels on the wall at that spot.

When you move the mirror and can see the drivers on the front of the speaker, not just the speaker itself. Their are going to be some points where you can still see the speaker, but it is not radiating mids or highs towards the walls. If you toe your speakers towards the listening space, then there is less energy in the mids and highs headed towards the walls. If you are using less than full range speakers, the thickness of the absorption material can be 2" to 3". If you are using full range speakers, then you need a bass traps, and first reflection material with at least a 3" thickness.

You must use broadband absorption for first order reflection if you are using full range speakers, or the spectral tilt of what you hear will move downward. In other words, you are absorbing the some of the mids, all of the highs, and none of the lows which are the biggest problem in small rooms.

If you are not using measurement equipment, this makes the job much tougher to get accurate results. Just putting up treatments without measurements is going to make this whole excersize a hit and miss proposition.

Sir Terrence the Terrible
05-18-2010, 10:19 AM
I have my room conditioning on order now. I've ordered six 2X4 feet (4 inch thick Owens Corning 703 boards) from the below site. Then I have ordered swaths from www.sewbatik.com. I'm planning on building a frame and covering it with the batik. The batik has a low thread count ( less then 200), so it should be fairly transparent to both high and low frequencies.

http://www.atsacoustics.com/item--Owens-Corning-703-4-inch--1032.html

I've attached photos of my listening room (with my old 684's), but the rooms the same. What I have done to the room:

-- I filled the space above the rear cabinets with insulation. Then wrapped the insulation in some nice silk low thread count cloth. It is surprising how this little bit of room treatment has improved the sound.


What I'm planning on doing next:

-- First, I designed and built this room before I understood the importance for room treatments. So, the rear cabinets are in a terrible location. But, I'm stuck with them.

-- I have a bass reflection problem. In fact just by hanging insulation in the front corner and opening the door at the opposite side the room--it really improves the sound.

--So I'm planning on building two room treatments that will go in the front of the room and put them against the wall (please see attached drawing). I hoping that this will absorb the reflecteed bass, and generally improve the sound quality.


What do you guys think about this layout? From what I've read, this will improve the sound.


http://gallery.audioreview.com/showphoto.php?photo=6915&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6263&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6266&cat=500&ppuser=276367

http://gallery.audioreview.com/showphoto.php?photo=6265&cat=500&ppuser=276367

Traps must be angled so that there is some air between the trap and the corner of the wall. It should not be snug to the wall as you currently have them drawn in, or it will be less effective. You should really have more absorption behind the speakers as well, or your entire front wall will become a huge reflection zone between two traps.

It is also best if you cover the floor with carpet or some kind of sound absorption throw rug between your listening seat and speakers.(full carpet is always better though). The speaker sits closest to the floor, and it would be a complete waste of time to treat the walls and corners but not attack the floor the speaker sits on as well.

manlystanley
05-18-2010, 10:39 AM
Great help, Thanks! I've made a second drawing using your suggestions. I got 4 inch 703 boards, so I'm doing good with that. Does this look about right?

Also, how tall should the traps be?? Say, 2 feet tall in the middle of the wall? How about the corner?

Best Regards,
Stan




http://gallery.audioreview.com/showphoto.php?photo=6917&cat=500&ppuser=276367

atomicAdam
05-18-2010, 10:55 AM
I'm not sure I fully agree w/ STtT suggestion and example of what will happen if u don't have 3" material at the 1st reflection points. I'm using those fiber boards from HD, about an inch or less thick, and I certainly don't get a darker sound in my room. If anything, I would like a bit more bass at the seating position. But that could be speaker related or window related.

manlystanley
05-18-2010, 10:58 AM
I'm not sure I fully agree w/ STtT suggestion and example of what will happen if u don't have 3" material at the 1st reflection points. I'm using those fiber boards from HD, about an inch or less thick, and I certainly don't get a darker sound in my room. If anything, I would like a bit more bass at the seating position. But that could be speaker related or window related.


Interesting. I'll make sure to try both out and report back with what I found.

Best Regards,
Stan

Sir Terrence the Terrible
05-18-2010, 12:41 PM
I'm not sure I fully agree w/ STtT suggestion and example of what will happen if u don't have 3" material at the 1st reflection points. I'm using those fiber boards from HD, about an inch or less thick, and I certainly don't get a darker sound in my room. If anything, I would like a bit more bass at the seating position. But that could be speaker related or window related.

If your fiberboard is only an inch or less, then it is probably only absorbing the highest frequencies, and it not likely to be doing any reflection control in the mids or lower mids anyway. That is probably why the sound is not darker to you. Besides, you have not done any measurements, so you are not really sure how effective what you are using really is.

atomicAdam
05-18-2010, 04:18 PM
STtT you are correct in term of knowing how effective it is in the measurements, but, I can hear a significant difference in terms of soundstage change and stability of snare and cymbals in the room.

I've been thinking about getting a few more board and putting them together to see if I hear any other change. $60 ain't that much to try.

manlystanley
05-19-2010, 05:59 AM
STtT you are correct in term of knowing how effective it is in the measurements, but, I can hear a significant difference in terms of soundstage change and stability of snare and cymbals in the room.

I've been thinking about getting a few more board and putting them together to see if I hear any other change. $60 ain't that much to try.

AA, I don't know what the sound coefficients are of these boards are, but I'd like to suggest that you give these a try: http://www.atsacoustics.com/item--Owens-Corning-703-4-inch--1032.html

The below link gives the sound abortion factors for various frequencies for a broad range of materials:

http://www.bobgolds.com/AbsorptionCoefficients.htm

Hope this helps.

Best Regards,
Stan

Sir Terrence the Terrible
05-19-2010, 09:41 AM
AA, I don't know what the sound coefficients are of these boards are, but I'd like to suggest that you give these a try: http://www.atsacoustics.com/item--Owens-Corning-703-4-inch--1032.html

The below link gives the sound abortion factors for various frequencies for a broad range of materials:

http://www.bobgolds.com/AbsorptionCoefficients.htm

Hope this helps.

Best Regards,
Stan

Stan, you are headed in the right direction with 4" thickness of you have full range speakers. Learning about the coefficients of the different thicknesses of the foam(if you understand it) is the best approach to doing this.

atomicAdam
05-19-2010, 12:08 PM
Stan, you are headed in the right direction with 4" thickness of you have full range speakers. Learning about the coefficients of the different thicknesses of the foam(if you understand it) is the best approach to doing this.

So here is a link to the stuff I found and am using from HomeDepot.
http://www.templeinland.com/BuildingProducts/Fiberboard/SoundChoice/

I guess my measurement memory was wrong, it is only a 1/2 inch thick.

manlystanley
05-20-2010, 08:40 AM
Stan, you are headed in the right direction with 4" thickness of you have full range speakers. Learning about the coefficients of the different thicknesses of the foam(if you understand it) is the best approach to doing this.

STtT, Thanks for the pointers. If I have anymore questions I get back to you all. They should be here today and I have today off, so I'll enjoy seeing what difference they make.

Besides, my other projects for today are:
-- Finish putting in me brake pads and rotors on my 98 Volvo (Have two frozen bolts--yuk).
-- Do a complete cooling system maintenance on the family van: back flush engine, install new Coolant, water pump, thermostat, and serpentine belt.

So, guess what I'm going to make time for first........ :D


Best Regards,
Stan

Sir Terrence the Terrible
05-20-2010, 10:10 AM
So here is a link to the stuff I found and am using from HomeDepot.
http://www.templeinland.com/BuildingProducts/Fiberboard/SoundChoice/

I guess my measurement memory was wrong, it is only a 1/2 inch thick.

I think you are mixing up sound deadening material with reflection control material. Sound deadening boards are for construction to isolate and keep sound within a room. Reflection control is designed to absorb random scattering of reflections that lead to slap echo and various other acoustical issues.

What you have here is akin to Owens and Cornings Quiet zone boards that i used to build my hometheater room in my Oakland house. It does nothing to control reflection within the room.

manlystanley
05-20-2010, 12:38 PM
This is amazing! I put all 12 (2 x 4) by 4 inch panels in my listening room. The change in sound was substantial. What I noticed:

-- Just carrying in the first box into the room made the bass level jump to the point that it was just to much.

-- After after placing the 9 panels around the room everything sounds so much better. I hear things that I never hard before.

-- Jamo speakers do better with female vocals then with males. But, the corning 703's improved the sound of both. To the point that on multiple tracks: the 3 dimensional imaging and sound made it sound like the female singer was in the room with me. Very earry .

-- However, even with the week points of the speakers, the 703 sound absorbers change the sound from: 'just good' to 'very good'.

I'll be playing around with moving things for the next few weeks, then when I'm satisfied with the layout I'll put the boards in frames and cover them with batik (that has less then 200 thread count to assure transparency.

Thanks for all your help.

Best Regards,
Stan

Woochifer
05-21-2010, 05:14 PM
Congrats!

My experience with using homemade acoustic panels is that the sound absorptive/reflective properties of commercially available products like fiberboards are documented and consistent. Compared to a bare wall or bare floor, a fiberboard will have more consistent acoustical properties across the audible spectrum. The issue with room acoustics is that different flooring and wall materials reflect and absorb sounds at different rates for different frequencies, which changes the tonal characteristics.

Just eliminating the slap echo will render a more precise and coherent sound. Basically, improving your room acoustics will let you better hear how your system is supposed to sound.

Sir T is correct in that the thickness is what determines how effectively the fiberboards will work in the lower frequency ranges. Unfortunately, bass problems are the most difficult ones to correct just with room treatments.

The principle behind bass traps is to attenuate the low frequencies and also reshape the corner so that you don't get too much reinforcement of those frequencies. The room interactions with bass frequencies create simultaneous cancellations and reinforcements.

It all depends on the location of your seat, relative to where your speakers are positioned. In one location within the room, the bass might sound anemic because of wave cancellations at specific frequencies. Concurrently, the room might also create interactions that cause huge frequency peaks, making the bass sound overly boomy.

If you have a subwoofer or plan to acquire one, the advantage to a subwoofer is that you can make adjustments to levels and independently position the unit to where the bass is smoothest. (The location where your main speakers sound best might not provide for the best bass) The subwoofer also gives you the option of using a parametric EQ to correct the frequency peaks at your seat location. I use a parametric EQ with my sub, and it's truly amazing how much it smoothed out the bass and improved the overall sound of my system.

poppachubby
05-22-2010, 06:21 AM
Man, how did I miss this thread?!? This is the best thread I've read in a while! Stan, you rock man.

I've done alot of reading on this subject, although I can't parrot much of it. It really comes down to getting out of the seat and labouring. All told I spent about 2 months monkeying around.

When it was all said and done, I have 6 bass traps and only a bit of damping for the front and rear walls. The room sounds great and when people come down, they immediatly sense the change in acoustics. Although not as extreme, it's akin to walking into a studio.

The bass traps removed the boominess and created a real authority. A kick drum is tight and punchy, as it should be. Bass guitar is also more natural sounding with no honky resonances.

Anyhow, Terrence is most correct, without proper techniques to measure it becomes a real labour of love.

manlystanley
05-24-2010, 04:28 AM
Pops, Woochifer, STtT, AA & JoEE,
I'm making really goo progress with the room treatment. I've brought multiple members of my family down and they all say: Rooms looks awfull, but sound great....

I got the swatches in from www.sewbatik.com . They are a great company and have a great product, but the thread count is to high for room treatments. I've heard that you need to be able to blow through the cloth without much resistance. This cloth is to dense and so would reflect higher frequencies.

Do you all agree with that "rule of thumb"?

Thanks,
Stan

Sir Terrence the Terrible
05-25-2010, 08:30 AM
Pops, Woochifer, STtT, AA & JoEE,
I'm making really goo progress with the room treatment. I've brought multiple members of my family down and they all say: Rooms looks awfull, but sound great....

I got the swatches in from www.sewbatik.com . They are a great company and have a great product, but the thread count is to high for room treatments. I've heard that you need to be able to blow through the cloth without much resistance. This cloth is to dense and so would reflect higher frequencies.

Do you all agree with that "rule of thumb"?

Thanks,
Stan

For the cloth that covers the panel, I absolutely agree. Fabric that is too dense will reflect instead of allowing the sound to pass through and hit the acoustic panel.

manlystanley
05-25-2010, 10:06 AM
For the cloth that covers the panel, I absolutely agree. Fabric that is too dense will reflect instead of allowing the sound to pass through and hit the acoustic panel.

STtT,
Thanks. Here is a really interesting link I found:

http://www.pinkfishmedia.net/forum/showthread.php?t=59093

It shows the effect of different types of cloth on different frequencies. It seems that light cotton is the best pass through.


Best Regards,
Stan

manlystanley
05-26-2010, 02:28 AM
Here's a link to a guy who is building his own frames for the room treatments. He's got some great little tips about how to miter the frames.

http://www.hometheatershack.com/forums/home-theater-design-construction/8354-tanner-ridge-cinema-construction-thread-7.html

Best Regards,
Stan

manlystanley
05-28-2010, 07:33 AM
I've had the corning 703's for over a week now, and have tried them in all kinds of postilions. What I've found that works best is placing them: In front of room; and then line the side walls from the first reflection point, to the front of the room. So the 9 boards all look pushed towards the front of the room.

I am amazed how good this sounds! I just got through listening to Rimsky-Korsakov's Piano Concerto, In C-Sharp (OP 30). The sound--as well as--the emotion that came through was amazing!

I'm planning on building the frames this weekend. I'll send pictures when I'm done.

Best Regards,
Stan

manlystanley
07-24-2010, 12:28 PM
Well, it's almost two months later and I just got the frames built. I've been working a lot on my kids cars. Now, I'm helping my second son rebuilt his truck engine before he takes it of grad school. I'm out with him in 100+ degree heat, sweating like a pig......


Anyways, I mounted the frames on the wall and I am still incredibility impressed at how good they make my system sound.

For example:

-- The system is so much more detailed and crisp sounding. I listen to alot of Cristian Celtic music. Before the room treatment I could not make out all the words because of the thick Scottish/Irish accents...... Now, it's clear as a bell.

-- Bass is tight and very full. Even my very hard to please wife was impressed (but she still hates how the room treatments look).
-- My main nit about the Jamo C809's is that I wished they were a bit more in your face. Well, they are now. I'm just reveling in the sound. Very nice.

-- I've got to get pictures up some time.

Best Regards,
Stan

Sir Terrence the Terrible
07-24-2010, 07:28 PM
Congrats young fella, now lets see some pics when you are done. I can't wait!

Nasir
07-25-2010, 01:30 PM
Without a doubt, speaker placement and room treatments open up the sound like nothing else. Personal experience with ESLs suggest some reflection is good, however with cone speakers the equation is different, nothing like trial end error to get the best out of one´s gear!!

manlystanley
07-25-2010, 05:57 PM
Congrats young fella, now lets see some pics when you are done. I can't wait!

"Young Fella"...... STtT, you are my friend for life! I have not been called that for years..... I don't feel so old now.



Best Regards,
Stan

manlystanley
07-29-2010, 07:22 PM
As promised, here's the pictures. I have not gotten the fabric yet, when I get them all covered I'll send some pictures of that too.

Picture of one Panel:

http://forums.audioreview.com/attachment.php?attachmentid=7230&stc=1&d=1280459320


Picture of: The left side of the room.

http://forums.audioreview.com/attachment.php?attachmentid=7232&stc=1&d=1280459917


Picture of the right side of the room (Minus one panel that I'm making to fit on the door).

http://gallery.audioreview.com/data/audio//500/thumbs/Stans_Right_Side.jpg


Close up picture of the left row.
http://gallery.audioreview.com/data/audio//500/thumbs/Stans_Row.jpg


Close up picture of the back (which shows how I attached them to the wall).
http://gallery.audioreview.com/data/audio//500/thumbs/Stans_Back.jpg

manlystanley
08-04-2010, 01:07 PM
So..... I've got five of the eight panels and they look gorgeous!! The material is a velvety suede looking material that I can easily blow through. Because of the roughness, it picks up more of the high frequencies and helps even more with imaging.

Finally, my wife comes down and looks at them and says: They look good. Wow, from my understated wife, what a complement....

Thanks again for all your help.

Best Regards,
Stan

kexodusc
08-04-2010, 01:17 PM
Great to hear....panels were one of the biggest improvements I made in my system, better than many experiments with various electronics, speakers etc. Not so much in the ability to reproduce detail, but to allow the resolution present to actually be heard.

Nice job on the frames, btw.

manlystanley
08-04-2010, 04:46 PM
Not so much in the ability to reproduce detail, but to allow the resolution present to actually be heard. .

Interesting. I have the same sort of thing. With the panels, the ability to actually make out all the words of songs is drastically improved. Not to mention that the bass is so much improved.

Best Regards,
Stan

JoeE SP9
08-04-2010, 07:30 PM
Manly, what fabric did you settle on and where did you get it? You're looking real good there. We're all waiting for the pictures of the finished room.

manlystanley
08-05-2010, 03:03 AM
Manly, what fabric did you settle on and where did you get it? You're looking real good there. We're all waiting for the pictures of the finished room.

Hello Joe,
Here is the (Royal Velvet) Fabric that I went with, I used the 'DUNE' Color. It is a neutral color that is grayish / tanish:

http://www.dazian.com/cgi-bin/page.pl?action=show_style&style_id=57&group_id=81&cat_id=29

I like the Royal Velvet for multiple reasons:

-- It has a suede like look and so has a lot of visual interest. On big pieces it has random patterns. I tried lots and lots of batiks, but they all were too thick. I tried blowing through the various batiks and no air would pass. This is important to make sure that sound will not be reflected.

-- I had Dazian, Inc send me four different sets of samples. I thought they'd get tired of me, but they were just really nice.

-- Somewhere on the net a guy did a acoustic analysis of Royal Velvet and found that it was the most transparent of even the specialty acoustic fabrics.

-- Finally, my wive likes the fabric and actually thinks that the panels look nice in the room. This by itself is a minor miracle.....

Best Regards,
Stan

JoeE SP9
08-05-2010, 07:07 AM
Thanks manly. I'm going to get some samples. My current bass traps look like examples from the agricultural school of design. Some nice fabric coverings will do a lot for my decor.

manlystanley
08-05-2010, 09:26 AM
Joe:
Dazian has all kinds of weights and styles of fabric (not to mention colors!). If you just have bass traps then you might not need acoustically transparent material. I'd ask for lots of other sample fabric styles as well, such as: Sculptured Velvet, Animal Skin (Synthetic), Venetian Velvet, Sculptured Milano Velvet, etc...... They have tons of styles and are very happy to send samples and color charts.

It took two months until my wife and I found the one that we liked.

Best Regards,
Stan

manlystanley
08-05-2010, 10:12 AM
BTW: If you want to try out some batik, try out this site. They were great on sending samples and were supper friendly:

http://www.sewbatik.com/Products.aspx

Best Regards,
Stan

JoeE SP9
08-05-2010, 04:40 PM
I'll give them a look also. Thanks.

manlystanley
08-06-2010, 09:59 AM
The room conditioning pannels are complete, and they look great!! However, the sound has really changed. For example:

-- The above the speaker imaging has suffered. I loved hearing the instruments seeming fly above the speakers. It's there still, but not as distinct.
-- The speakers are much more forward now with treble.
-- In general very different sounding. Not sure if I like it or not. But, they look great.

Best Regards,
Stan

manlystanley
08-07-2010, 05:11 AM
I decided that I really missed the imaging that I had before I wrapped the panels. There are multiple tracks that I have were percussion instruments (tambourines, casements, etc) would seem to fly back and forth above the speakers. It gave a really cool audio effect.

So, I started to experiment. It turned out that putting just one more panel on the front door fixed the problem. I did a two hour listening test and so far it really sounds great. What I have learned about the wrapping process is:

-- What ever cloth you use, it will effect mainly the higher frequencies absorption rate. So, make sure that you get room treatment that absorb *more* high frequencies that you want. This way with the wrapping it will balance out well.

-- I had been saying that my Jamo C809's did not 'present harsh sounds' properly. We'll, with this wrapping it drastically improves that. I think the bare insulation was absorbing the to much of the high frequencies.

-- From what I've learned about room conditioning, I can now understand how there can be such drastic differing opinions of audio equipment. The sound heard really depends on so many things--that are not related to the equipment being discussed about.

-- I am hearing such a subtle blend of sounds now. The little nuances that I could not hear before are adding so much to my musical enjoyment. I am very, very happy with how the room conditioning: sounds and looks.


-- My wife who was up in arms about me 'wrecking a beautiful room'. Now she says that the room conditioning looks really nice. I have to agree. The suede has these micro random patterns that is very attractive. Then the frames are cut in a way to have two distinct lines on each side. It give the panels are real crisp look.


Finally, I really appreciate all your help. I've tried to return your kindness by relaying what I've learned. I hope it's helps you out in some way. For a total of $400 for all: insulation, wood, cloth and hanging hardware--this has given a drastic improvement to the sound quality.

I'll go and get some pictures of the final result and post them. Then that will finish out this thread.

Best Regards,
Stan

kexodusc
08-07-2010, 05:57 AM
This has been a fun thread to follow. Thanks for sharing Stan. Where exactly do you have them all positioned now?

manlystanley
08-16-2010, 05:00 AM
This has been a fun thread to follow. Thanks for sharing Stan. Where exactly do you have them all positioned now?


Sorry it took so long. Here's the room layout. Also, I have room conditioning on top of the cabnets as well. I'll try to get pictures shortly. I'm glad that you found the thread fun to follow!

Best Regards,
Stan

http://forums.audioreview.com/attachment.php?attachmentid=7288&stc=1&d=1281963548

manlystanley
08-17-2010, 02:49 AM
Hello Thomas,
Room treatment is placing sound absorbing material at key locations in your listening room. SOme of the key benifets or this is:

-- Bass response will greatly improve. This is because the the period time (e.g. wave length) of lower frequencies are many feet long. So they will cancel out as the various phases bounce off the walls. In fact, many people report that the the bass sounds better in the adjacent room, instead of the room where the stereo is located at.

-- Clarity is greatly improved. All the sound bouncing off the walls will muddy the sound.

-- Imaging is greatly improved. as above.

Best Regards,
Stan

manlystanley
08-21-2010, 04:42 AM
It's taken a while, but here's the finished product:

http://forums.audioreview.com/attachment.php?attachmentid=7311&stc=1&d=1282394137

http://forums.audioreview.com/attachment.php?attachmentid=7312&stc=1&d=1282394137

http://forums.audioreview.com/attachment.php?attachmentid=7313&stc=1&d=1282394350

http://forums.audioreview.com/attachment.php?attachmentid=7314&stc=1&d=1282394350


Best Regards,
Stan

Sir Terrence the Terrible
08-21-2010, 08:41 AM
Bravo, Bravo (jumping up and down and clapping wildly), these things look great!!!!:thumbsup:

Holy smokes good job Manlystanly type individual. I wish I had your skills:yesnod:

JoeE SP9
08-21-2010, 09:14 AM
That's one good looking room. I see the main chair in the "sweetest spot". You make me want to redecorate my poor bachelor digs.

It can be my winter project. I wanted new furniture anyway. New nice looking acoustic treatments will be part of my redecorating. Thanks for giving me something to aim for.

Sir Terrence the Terrible
08-21-2010, 10:25 AM
That's one good looking room. I see the main chair in the "sweetest spot". You make me want to redecorate my poor bachelor digs.

It can be my winter project. I wanted new furniture anyway. New nice looking acoustic treatments will be part of my redecorating. Thanks for giving me something to aim for.

Good luck on your project Joe, I am in the middle of some major upgrades as well.

manlystanley
08-21-2010, 11:33 AM
Joe and STtT,
Coming from you guys, your kind words mean a lot! I've learned so much from AR and when I can I love to return the favor.

Best Regards,
Stan

frenchmon
08-21-2010, 01:39 PM
Very Nice...you go fella!

jrhymeammo
08-29-2010, 07:38 PM
Hey Stan,

The room looks great. I think we all agree that you've done a great job.
Based on what I see, you look like a handy guy. Have you considered making DIY Corner Trap?
http://www.realtraps.com/tri-corner.htm



-- In general very different sounding. Not sure if I like it or not. But, they look great.
Over damping of the room can suck out music.
Do you think you've done that?
I don't have data to back it up but based on my taste, placing THICK panels in overly exciting room unbalance the room acoustics. I don't think it sounds natural to have overly LIVE walls and having DEAD sections. If I had to exaggerate it, it's kinda like listening to music thru a pair of Noise-cancelling headphones, and having only one channel activated.

The room treatment is a piece of audio gear. Much like components, we all have our own taste, so we just need to find what we like best. I don't think I've found what I like yet.

What's the dimension of your room? (Perfect square?).
Also, can you use your cabinet as a large diffusor?

Thanks again for the great thread!!!

Have Fun,
JRA

manlystanley
08-30-2010, 06:04 AM
Hey Stan,

The room looks great. I think we all agree that you've done a great job.
Based on what I see, you look like a handy guy. Have you considered making DIY Corner Trap?
http://www.realtraps.com/tri-corner.htm



Over damping of the room can suck out music.
Do you think you've done that?
I don't have data to back it up but based on my taste, placing THICK panels in overly exciting room unbalance the room acoustics. I don't think it sounds natural to have overly LIVE walls and having DEAD sections. If I had to exaggerate it, it's kinda like listening to music thru a pair of Noise-cancelling headphones, and having only one channel activated.

The room treatment is a piece of audio gear. Much like components, we all have our own taste, so we just need to find what we like best. I don't think I've found what I like yet.

What's the dimension of your room? (Perfect square?).
Also, can you use your cabinet as a large diffusor?

Thanks again for the great thread!!!

Have Fun,
JRA

I gave a lot of thought to putting in corner bass traps, but I decided to just do panels instead. I'm pleased with my choice as it adds a lot of detail and bass to the sound.

Previously I had HUGE standing wave issues. Now, I still have them, but significantly smaller.

Dimensions: close to a square (20 x 24 feet).

I have not experienced that problem with thick room acoustic treatments. Mine just add to the sound.

Best Regards,
Stan

Sir Terrence the Terrible
08-30-2010, 09:59 AM
I gave a lot of thought to putting in corner bass traps, but I decided to just do panels instead. I'm pleased with my choice as it adds a lot of detail and bass to the sound.

Previously I had HUGE standing wave issues. Now, I still have them, but significantly smaller.

Dimensions: close to a square (20 x 24 feet).

I have not experienced that problem with thick room acoustic treatments. Mine just add to the sound.

Best Regards,
Stan

Here is a tip when you are working with a square or almost square room. Move the sub away from the corner, and towards the center of the front wall. This will reduce the excitation of the room deminsion based modes and nodes, and decrease the amplitude of any standing waves in the room.

Geoffcin
08-30-2010, 12:16 PM
Here is a tip when you are working with a square or almost square room. Move the sub away from the corner, and towards the center of the front wall. This will reduce the excitation of the room deminsion based modes and nodes, and decrease the amplitude of any standing waves in the room.

I would say that's a good tip in almost any shaped room.

Sir Terrence the Terrible
08-30-2010, 12:54 PM
I would say that's a good tip in almost any shaped room.

Not with rectangular rooms, the corner is still the best place for subs in that case. The problem with mid front wall placement is the LF penalty you get from that placement. Three months ago I was mulling through some white papers and found one by Tom Nousiane(I know E-stat hates this guy, and does not respect his research much). He measured 4 subwoofer with midwall placement against a single sub in a corner. The sub in the corner outperformed the 4 midwall subs in every parimeter, and at every frequency except around 40hz where the 4 midwall subs had 1.5db of extra output. Distortion was lower at all frequencies, output was higher at all frequencies, and below 40hz it was no competition with the single sub basically trouncing the midwall subs. The midwall subs were working twice as hard as the single sub(cone movement was higher as was distortion), and below 40hz the distortion jumped profoundly.

E-Stat
08-30-2010, 04:46 PM
The sub in the corner outperformed the 4 midwall subs in every parimeter, and at every frequency except around 40hz where the 4 midwall subs had 1.5db of extra output. Distortion was lower at all frequencies, output was higher at all frequencies, and below 40hz it was no competition with the single sub basically trouncing the midwall subs.
That's what happens when you compare apples to oranges. Using the same subs, however, one would expect reduced output away from the walls. Lower distortion, on the other hand, has to do with the drivers, cabinet and amplifiers used. Speakers have no realization of where they're placed as they play.


The midwall subs were working twice as hard as the single sub(cone movement was higher as was distortion), and below 40hz the distortion jumped profoundly.
The tradeoff is output vs coloration. Take your pick.

rw

jrhymeammo
08-30-2010, 05:41 PM
Very cool, man.

Sir Terrence the Terrible
08-30-2010, 06:44 PM
That's what happens when you compare apples to oranges. Using the same subs, however, one would expect reduced output away from the walls. Lower distortion, on the other hand, has to do with the drivers, cabinet and amplifiers used. Speakers have no realization of where they're placed as they play.

All the subs were the same(more assumption again!!!!). If a subwoofer does not get the corner loaded gain(9db in a corner), it will have to work harder to play back at levels that a corner loaded sub does. If you turn up the volume trying to achieve it, it will will require more power and increase cone movement which leads to more distortion. If you trying and create a house curve to match the low frequency output of the corner loaded sub, it will require more power and increase driver movement which will increase distortion. A speaker may not have a realization of where they play, but the corner sure realizes it is there.



The tradeoff is output vs coloration. Take your pick.
rw

It is not a take you pick proposition. If you are speaking of resonances, you are going to have them unless the subwoofer is suspended halfway between the floor and ceiling, and in the middle of the room. The other coloration can come from the distortion of the amp, as it is pushing the driver harder to achieve the lower extension and higher output with mid wall positioning. So the real tradeoff is dealing with room born colorations(which can be corrected), or coloration from amp distortion which cannot be corrected except by turning the sub down, which works against getting high output at low frequencies.

E-Stat
08-30-2010, 06:56 PM
All the subs were the same(more assumption again!!!!).
You're right. I subsequently found the in-depth report here. (http://www.nousaine.com/pdfs/Multiple%20Subwoofers.pdf) If there's anyone stupid enough to place four woofers at the mid points of all four walls, then the message is clear: don't do that. Naturally, he doesn't bother to state a single aspect of what gear was used. HTIB subs?


If a subwoofer does not get the corner loaded gain(9db in a corner), it will have to work harder to play back at levels that a corner loaded sub does. If you turn up the volume trying to achieve it, it will will require more power and increase cone movement which leads to more distortion.
Exceeding a design's ideal range is not a particularly good idea.


A speaker may not have a realization of where they play, but the corner sure realizes it is there.
As does your ear.


...coloration from amp distortion which cannot be corrected except by turning the sub down, which works against getting high output at low frequencies.
I agree that it is pretty stupid to overdrive any speaker. I especially like this (http://www.nousaine.com/pdfs/Most%20Common%20Autosound%20Quality%20Errors.pdf) gripping and epic tale of his. ;)

rw

Sir Terrence the Terrible
08-30-2010, 07:30 PM
You're right. I subsequently found the in-depth report here. (http://www.nousaine.com/pdfs/Multiple%20Subwoofers.pdf) If there's anyone stupid enough to place four woofers at the mid points of all four walls, then the message is clear: don't do that. Naturally, he doesn't bother to state a single aspect of what gear was used. HTIB subs?

When this paper was published in Stereo Review, I believe he used a Velodyne F-1800x.



Exceeding a design's ideal range is not a particularly good idea.

Nope, that is why a mid wall location is really only applicable to small rooms and very powerful subs.



As does your ear.

Correct, and more so if the ear is near a wall as well.



I agree that it is pretty stupid to overdrive any speaker. I especially like this (http://www.nousaine.com/pdfs/Most%20Common%20Autosound%20Quality%20Errors.pdf) gripping and epic tale of his. ;)

rw

LOL! I don't pay much attention to is car stereo stuff, my car is not an ideal place for good audio anyway. Too much background noise will kill the dynamics of a good recording.

Geoffcin
08-31-2010, 02:33 AM
Not with rectangular rooms, the corner is still the best place for subs in that case. The problem with mid front wall placement is the LF penalty you get from that placement. Three months ago I was mulling through some white papers and found one by Tom Nousiane(I know E-stat hates this guy, and does not respect his research much). He measured 4 subwoofer with midwall placement against a single sub in a corner. The sub in the corner outperformed the 4 midwall subs in every parimeter, and at every frequency except around 40hz where the 4 midwall subs had 1.5db of extra output. Distortion was lower at all frequencies, output was higher at all frequencies, and below 40hz it was no competition with the single sub basically trouncing the midwall subs. The midwall subs were working twice as hard as the single sub(cone movement was higher as was distortion), and below 40hz the distortion jumped profoundly.

Well it makes sense that out of the corner your going to loose output, but it all depends on the sub if your going to push it into distortion in another placement. With my 2 Velodyne FSR15's, corner placement just isn't necessary to pressurize the room. I also spent some time with a dB meter moving them around to try to get the best performance in room. My room is 21' x 16' (a rectangle) and the absolute WORSE performance with either subs engaged or both was a corner placement. I got nearly 20dB shifts across the room with such a placemen!

Geoffcin
08-31-2010, 03:55 AM
You're right. I subsequently found the in-depth report here. (http://www.nousaine.com/pdfs/Multiple%20Subwoofers.pdf) If there's anyone stupid enough to place four woofers at the mid points of all four walls, then the message is clear: don't do that. Naturally, he doesn't bother to state a single aspect of what gear was used. HTIB subs?
rw

Well that was fun to read! What exactly was he trying to prove except that he's got 4 subs to play with and a lot of time on his hands? It's application to anything remotely resembling what would be used in a HT is laughable!

I would say that if he's got four subs and was only able to generate 106dB at 62Hz (at 10% distortion no less!?) then he's got low spec subs for sure. One of my Velodynes would easily surpass that in room with less than 1% distortion.

E-Stat
08-31-2010, 05:06 AM
When this paper was published in Stereo Review, I believe he used a Velodyne F-1800x.
If so, he wasted his time more than once. I refer to the paper found on his website here (http://www.nousaine.com/nousaine_tech_articles.html) which makes no so such mention of - well anything. Great job as usual.


... is really only applicable to small rooms and very powerful subs.
Translation: they were overdriven for their size.


I don't pay much attention to is car stereo stuff, my car is not an ideal place for good audio anyway. Too much background noise will kill the dynamics of a good recording.
That's his audio specialty! Don't you realize he has tested over 900 car stereos? I can't think of anything I'd rather not do. :)

rw

Sir Terrence the Terrible
08-31-2010, 09:29 AM
If so, he wasted his time more than once. I refer to the paper found on his website here (http://www.nousaine.com/nousaine_tech_articles.html) which makes no so such mention of - well anything. Great job as usual.

I am not sure that mentioning the name of the sub makes any difference. That is majoring in minors to me. His methodology is sound(as always) even if he doesn't go into any details on the equipment. Just a question, why do equipment lists mean so much to you? Are you using that knowledge to invalidate an argument?(which is not really possible if the science is correct)



Translation: they were overdriven for their size.

VERY very poor translation. That was not what I meant at all!!



That's his audio specialty! Don't you realize he has tested over 900 car stereos? I can't think of anything I'd rather not do. :)

rw

That may be his specialty, but his speaker and subwoofer tests are done just like every other reviewer out there. The measurements are taken just like every other reviewer does, and they are published with the review just like every other reviewer does. When he publishes his white papers, they get the same scrutiny by his peers that everyone else gets, I have not seen anyone refute anything he has published. You may dislike him, but can you refute his testing methodology? That is the question, not the personal like or dislike.

Sir Terrence the Terrible
08-31-2010, 09:45 AM
Well that was fun to read! What exactly was he trying to prove except that he's got 4 subs to play with and a lot of time on his hands? It's application to anything remotely resembling what would be used in a HT is laughable!

Not exactly Geoff. As a result of a white paper by Todd Welti of Harmon Kardon, folks are making recommendation for midwall placement to avoid a rooms modes and nodes. It doesn't really avoid them, but midwall placement excite them less, but with a low frequency penalty and higher distortion.


I would say that if he's got four subs and was only able to generate 106dB at 62Hz (at 10% distortion no less!?) then he's got low spec subs for sure. One of my Velodynes would easily surpass that in room with less than 1% distortion.

He used the Velodyne F-1800x, which are a bit more powerful than your velodynes. You also have to keep the room volume in mind when taking that measurement under consideration. Also you have to take the subs crossover point which I think is 80hz. This sub is voiced to be more effective at the bottom of its range than the top. 18" drivers do not make good midbass drivers.

E-Stat
08-31-2010, 09:52 AM
I am not sure that mentioning the name of the sub makes any difference.
Nothing that he writes makes any difference. Providing test conditions would, however, illustrate my point about overdriving.


His methodology is sound(as always) even if he doesn't go into any details on the equipment. Just a question, why do equipment lists mean so much to you? ...Are you using that knowledge to invalidate an argument?(which is not really possible if the science is correct
Tests prove what they prove only upon that which is used. Period. Unfortunately, there are some "researchers" who extrapolate sweeping conclusions from their limited test samples to the universe of all units that are in no way supported by their evidence. His website contains many comical versions of this approach.



You may dislike him, but can you refute his testing methodology? That is the question, not the personal like or dislike.
Real science seeks to replicate a given researcher's findings. Real science papers always contain methodology and test procedures REQUIRED for duplication. His tests are a joke to anyone who understands these concepts. For those who like booming subs in their cars, however, his reading serves a purpose.

rw

Sir Terrence the Terrible
08-31-2010, 10:03 AM
Nothing that he writes makes any difference. Providing test conditions would, however, illustrate my point about overdriving.

He outlines the room size, speaker positioning, and the equipment used for measuring. What other test conditions do you need when the object is to test for best location for subs??



Tests prove what they prove only upon that which is used. Period. Unfortunately, there are some "researchers" who draw sweeping conclusions from their limited tests that are in no way supported by their evidence. His website contains many comical versions of this approach.

Are you saying that testing is not valuable?

You seem to be coming from a superior position in your comments. Have you done any testing of subs or speakers?

In this case his results are supported by evidence. I am speaking directly to this test, not the others he has done. Those test(whatever they are) are not related to this discussion at all.




Real science seeks to replicate a given researcher's findings. Real science papers always contain methodology and test procedures REQUIRED for duplication. His tests are a joke to anyone who understands these concepts. For those who like booming subs in their cars, however, his reading serves a purpose.

rw

Ralph, this is blather. What in his testing methods(in this case) are troubling to you? The methodology is there, as is his testing procedure. What else does he need, and why does he continue to pass peer review? If he passes peer review, then what you think is irrelevant. :)

Geoffcin
08-31-2010, 10:23 AM
Not exactly Geoff. As a result of a white paper by Todd Welti of Harmon Kardon, folks are making recommendation for midwall placement to avoid a rooms modes and nodes. It doesn't really avoid them, but midwall placement excite them less, but with a low frequency penalty and higher distortion.



He used the Velodyne F-1800x, which are a bit more powerful than your velodynes. You also have to keep the room volume in mind when taking that measurement under consideration. Also you have to take the subs crossover point which I think is 80hz. This sub is voiced to be more effective at the bottom of its range than the top. 18" drivers do not make good midbass drivers.


No way! He's using FOUR F-1800's and he can't get past 106dB?! Four of those puppies could fill a large movie theater to that SPL. I read that paper top to bottom and didn't see any info on the size or brand of sub used to make it. Where are you seeing this?

E-Stat
08-31-2010, 10:34 AM
He outlines the room size, speaker positioning, and the equipment used for measuring. What other test conditions do you need when the object is to test for best location for subs??
How about what subs were used? Duh! Do you think you might get different results using Onkyo SKW 204s or JLA Gothams? That is not a trick question.


Are you saying that testing is not valuable?
I value tests which provide enough data for replication. I've heard enough components over the past forty years to understand differences exist. Extrapolated conclusions - as we find he likes to do - are useless.


In this case his results are supported by evidence. I am speaking directly to this test, not the others he has done. Those test(whatever they are) are not related to this discussion at all.
For that one model of subwoofer used. Let's return to my answer to your first question. Do you honestly think the results would have been the same for every sub available today? He seems to think so!


What else does he need, and why does he continue to pass peer review? If he passes peer review, then what you think is irrelevant. :)
While you find the need to ask the same question multiple times, I feel no need to answer it multiple times. My response hasn't changed.

Try reading "Flying Blind". This is his *proof* that in all cases, short term comparisons are more valuable than long term listening. Well, if your objective is detecting adding harmonic distortion, then his test may have validity. I've taken an online ABX test like that before. Does the conclusion, however, from a singly purposed (and contrived) test cover a W-I-D-E range of more discerning kinds of differences that you actually find in recordings? Does a Joan Baez recording represent the absolute best in recording practices and quality? The answers to these questions should be obvious to anyone.

rw

Geoffcin
08-31-2010, 10:41 AM
Is this is the study your quoting;

http://www.nousaine.com/pdfs/Multiple%20Subwoofers.pdf

If so then I would take it all with a grain of salt. Nousaine himself says that it was flawed from the outset because of the room dimensions. I'm not sure why he didn't use a more standard sized room. Perhaps he just had four subs, a few joints, and a few hours to kill?

Sir Terrence the Terrible
08-31-2010, 04:50 PM
No way! He's using FOUR F-1800's and he can't get past 106dB?! Four of those puppies could fill a large movie theater to that SPL. I read that paper top to bottom and didn't see any info on the size or brand of sub used to make it. Where are you seeing this?

What you see is an excerpt from a white paper submitted to AES. It was peer reviewed and has not been challenged. I have the white paper that has all of the details including the sub used(actually there was more than one). His paper agrees with a white paper by Dr. Floyd Toole on the same subject

While the F-1800 is indeed a powerful sub, it was not the loudest sub he has tested. This sub was also tested by Richard Hardesty of Widescreen Review, and his SPL numbers(using the 10% distortion perimeter) got the same overall SPL results as Nousaine. Here are the numbers J Johnson's got on the same sub(just one though)

10 Hz - 97.0 dB
12.5 Hz - 100.2 dB
16 Hz - 97.8 dB
20 Hz - 93.0 dB
25 Hz - 95.0 dB
31.5 Hz - 97.6 dB
40 Hz - 93.4 dB
50 Hz - 88.4 dB
63 Hz - 96.7 dB
80 Hz - 89.7 dB
100 Hz - 83.7 dB
125 Hz - 83.6 dB

This is from 3ft away from the sub. This is 13ft from the sub

10 Hz - 96.6 dB
12.5 Hz - 100.3 dB
16 Hz - 99.5 dB
20 Hz - 95.6 dB
25 Hz - 97.0 dB
31.5 Hz - 91.4 dB
40 Hz - 90.0 dB
50 Hz - 74.8 dB
63 Hz - 89.8 dB
80 Hz - 87.3 dB
100 Hz - 80.2 dB
125 Hz - 75.0 dB

As you can see, this sub is not voiced for strong mid bass performance, it is indeed a subwoofer. As the frequencies increase, this subs output decreases.

http://www.hometheaterhifi.com/volume_3_3/v3n3l.html

Sir Terrence the Terrible
08-31-2010, 04:58 PM
Is this is the study your quoting;

http://www.nousaine.com/pdfs/Multiple%20Subwoofers.pdf

If so then I would take it all with a grain of salt. Nousaine himself says that it was flawed from the outset because of the room dimensions. I'm not sure why he didn't use a more standard sized room. Perhaps he just had four subs, a few joints, and a few hours to kill?

Nowhere in this preliminary paper(because that is what it is) does it say the test was flawed. He stated the paper needed to be finished on a 20x15x8 ft room which was representative of a study which included the measurements of 250 rooms.

Why do folks have to be doing drugs just because some don't agree with his findings? Is this a way of dismissing his results? If I didn't like the results, I wouldn't attack the person, I attack the methodology if it weren't sound. In this case, his methodology was sound - as it passed peer review even folks don't like the end result.

Geoffcin
08-31-2010, 05:20 PM
Nowhere in this preliminary paper(because that is what it is) does it say the test was flawed. He stated the paper needed to be finished on a 20x15x8 ft room which was representative of a study which included the measurements of 250 rooms.

Why do folks have to be doing drugs just because some don't agree with his findings? Is this a way of dismissing his results? If I didn't like the results, I wouldn't attack the person, I attack the methodology if it weren't sound. In this case, his methodology was sound - as it passed peer review even folks don't like the end result.

Now you must be smoking something!

It's not his findings, methodology or his results that I find dopey. It's the fact hat there's nothing in the world of HT that anyone SANE (or not doped up) would do that would include putting 4 subs in the positions he did. To what purpose did he do this? And then call it some kind of study?! On man this is really funny!

Geoffcin
08-31-2010, 05:51 PM
What you see is an excerpt from a white paper submitted to AES. It was peer reviewed and has not been challenged. I have the white paper that has all of the details including the sub used(actually there was more than one). His paper agrees with a white paper by Dr. Floyd Toole on the same subject

As you can see, this sub is not voiced for strong mid bass performance, it is indeed a subwoofer. As the frequencies increase, this subs output decreases.

http://www.hometheaterhifi.com/volume_3_3/v3n3l.html

HA HA!! Where do you find this stuff?!

Oh yeah, I believe that the F1800 couldn't break 90dB at 80Hz. :lol: Just for kicks I tried my 15" at 80Hz and it just popped 107dB and I absolutely KNOW the 18" could play louder.

Just a cursory look at that sampling shows that's it's flawed in any number of ways. He measured 74dB @ 50Hz?! My little JmLabs monitors can best that! Oh man, thanks for the laughs!!

Sir Terrence the Terrible
08-31-2010, 06:28 PM
How about what subs were used? Duh! Do you think you might get different results using Onkyo SKW 204s or JLA Gothams? That is not a trick question.

Maybe because the object was not to test the subwoofer themselves, but the positioning of the sub. The sub in this case is not the focus, but this is just an excerpt from a larger body of work. Do I think he would get different results from a different woofer...perhaps more SPL, but it does not change the fact that that ANY subwoofer would suffer a LF penalty and higher distortion from mid wall positioning. Dr. Floyd Toole found this to be true in his white papers as well. It has nothing to do with any specific sub, it has everything to do with that subs interaction with the room. In his white paper(and I have said this earlier to you, but it looks like it bares repeating again) the sub he used was the F-1800x, that was in his peer reviewed white paper, along with the results of a smaller room as well. While the SPL was higher in the smaller room, the results were exactly the same.



I value tests which provide enough data for replication. I've heard enough components over the past forty years to understand differences exist. Extrapolated conclusions - as we find he likes to do - are useless.

He didn't extrapolate anything. He tested the subs in both the mid wall and corner placement, and showed the results. His testing and methodology passed peer review, so what you think of it is quite frankly irrelevant. Dr. Poole did the same test, and got basically the same results - there is a LF penalty with mid wall placement, and the distortion of the driver is increased as a result of long cone movements.



For that one model of subwoofer used. Let's return to my answer to your first question. Do you honestly think the results would have been the same for every sub available today? He seems to think so!

And he is right to think so. This is not about the sub, it is about the interaction of the sub with the rooms boudaries. He has never said anywhere that the SPL numbers would be the same with every sub and every room, and that is not the point. The point is that mid wall placement of any sub has a LF penalty, and with that penalty comes more distortion at lower frequencies. Use your brain for a second here. If you get a 9db increase in output without turning the volume knob with corner placement, but only get 3db from a mid wall(flat against the front wall), then logic dictates the mid wall placement will cause the sub to work harder at acheiving high output at low frequencies. This is regardless of the subs own capabilities, so the manufacturer of that sub is irrelevant.



While you find the need to ask the same question multiple times, I feel no need to answer it multiple times. My response hasn't changed.

I always have to ask the question multiple times with you, as you never seem to give an answer that applies to the question. It is always some BS filler response.


Try reading "Flying Blind". This is his *proof* that in all cases, short term comparisons are more valuable than long term listening. Well, if your objective is detecting adding harmonic distortion, then his test may have validity. I've taken an online ABX test like that before. Does the conclusion, however, from a singly purposed (and contrived) test cover a W-I-D-E range of more discerning kinds of differences that you actually find in recordings? Does a Joan Baez recording represent the absolute best in recording practices and quality? The answers to these questions should be obvious to anyone.

rw

And this is a prime example of the BS filler response. This does not have a damn thing to do with Nousaine results. This is not about recordings, it is not about Joan Baez, and it is not about some stupid book named "Flying Blind". This is about subwoofers and their interaction with room boundaries, can you stay with the program and cut the air sandwiches.

Sir Terrence the Terrible
08-31-2010, 06:31 PM
HA HA!! Where do you find this stuff?!

Oh yeah, I believe that the F1800 couldn't break 90dB at 80Hz. :lol: Just for kicks I tried my 15" at 80Hz and it just popped 107dB and I absolutely KNOW the 18" could play louder.

Just a cursory look at that sampling shows that's it's flawed in any number of ways. He measured 74dB @ 50Hz?! My little JmLabs monitors can best that! Oh man, thanks for the laughs!!

Geoff, your room might not be the same size his is. Room size has everything to do with with the total SPL you will get from your sub. At what distance did you measure, what measuring device did you use, and what was the distortion at 107db? Without that, your 107db is pretty meaningless. Remember, their benchmark was 10% distortion. Can your sub do 107db with less than 10% distortion?

He also had this disclaimer:

Frequency Response Test Results (These data represent tests in a real room with furniture, not anechoic tests or simulations, and thus, may be somewhat different than you might experience in your own listening room of other dimensions and contents):

Geoffcin
08-31-2010, 06:37 PM
Geoff, your room might not be the same size his is. Room size has everything to do with with the total SPL you will get from your sub. At what distance did you measure, what measuring device did you use, and what was the distortion at 107db? Without that, your 107db is pretty meaningless. Remember, their benchmark was 10% distortion. Can your sub do 107db with less than 10% distortion?

Actually my sub can't produce more than 1% distortion so I never worry about that. The reading I took was at about 3ft. Gain was maxed out, but I'm not sure the sub was. Still I find his reading extremely funny. I've never seen max SPL at 10Hz or 12Hz for even the newer big DD18.

Sir Terrence the Terrible
08-31-2010, 06:44 PM
Now you must be smoking something!

Or you are Geoff.


It's not his findings, methodology or his results that I find dopey. It's the fact hat there's nothing in the world of HT that anyone SANE (or not doped up) would do that would include putting 4 subs in the positions he did. To what purpose did he do this? And then call it some kind of study?! On man this is really funny!

Or really? Then you obviously don't read Sound and Video Contractor magazine which recommended such placement for large rooms based on the white paper submitted by Todd Welti of Harmon Kardon. As a matter of fact, you probably don't read any trade magazine on HT and sound room installation as this positioning has been promoted for a couple of years now. Nousiane research debunks that approach as a way of getting high SPL's at low frequencies.

You need to go to Hometheatershack where guys are building all kinds of crazy size subwoofers to see just what kind of craziness folks are doing. You are not going to find much of this craziness hanging around here all the time(even though it is a great place to hang out), you need to visit other websites and see exactly what other folks are doing, it might surprise you. I saw an installation in SVC magazine a couple of months ago that utilized 8 subwoofers(two subs stacked) at each of the four mid mid wall positions in the room. So yes, they do that kind of craziness out there.

Geoffcin
08-31-2010, 06:54 PM
OK while I hate digging around for this crap, but here's a analysis of the DD18. Obviously the DD18 is several generations better than the old F1800, but the response curves should be similar, even if the DD18 is much more capable in delivering more SPL at astonishingly low distortion.

http://www.audioholics.com/reviews/speakers/subwoofers/velodyne-dd-18/velodyne-dd-18-measurements-and-analysis

Geoffcin
08-31-2010, 07:02 PM
Or you are Geoff.

Or really? Then you obviously don't read Sound and Video Contractor magazine which recommended such placement for large rooms based on the white paper submitted by Todd Welti of Harmon Kardon. As a matter of fact, you probably don't read any trade magazine on HT and sound room installation as this positioning has been promoted for a couple of years now. Nousiane research debunks that approach as a way of getting high SPL's at low frequencies.
.

Well if he did it to debunk the "stoned" theory of the four subs of the then I would say it was a worthy effort. Perhaps Welti was the Amsterdam dropout in this case?

FWIW; I STILL think a lot of cannabis is consumed in this particular form of research.

E-Stat
08-31-2010, 07:17 PM
...but it does not change the fact that that ANY subwoofer would suffer a LF penalty and higher distortion from mid wall positioning.

...there is a LF penalty with mid wall placement, and the distortion of the driver is increased as a result of long cone movements.

The point is that mid wall placement of any sub has a LF penalty, and with that penalty comes more distortion at lower frequencies...

... mid wall placement will cause the sub to work harder at acheiving high output at low frequencies.
I guess if you feel you must overdrive a system, then you will get those results no matter how many times you say it to yourself.


I always have to ask the question multiple times with you, as you never seem to give an answer that applies to the question.
Then you don't understand the scientific principle. Very well.

rw

Sir Terrence the Terrible
08-31-2010, 07:58 PM
OK while I hate digging around for this crap, but here's a analysis of the DD18. Obviously the DD18 is several generations better than the old F1800, but the response curves should be similar, even if the DD18 is much more capable in delivering more SPL at astonishingly low distortion.

http://www.audioholics.com/reviews/speakers/subwoofers/velodyne-dd-18/velodyne-dd-18-measurements-and-analysis

Why would you assume their curves would be the same? The jump from the F-1800 generation to the DD-18 is huge when it comes to performance. The servo and limiters are adjustable with the DD-18, and the F-1800 had no such benefit. The driver was improved(and is different from the F-1800), as was the cabinet, the amp is a DASH amp as oppose to a B class amp with the F-1800.

There is so much that is different from these two subs that one cannot use the other to classify performance levels.

Sir Terrence the Terrible
08-31-2010, 08:13 PM
I guess if you feel you must overdrive a system, then you will get those results no matter how many times you say it to yourself.

If he used a 10% distortion figure as a benchmark, how in the hell would he be overdriving a sub? I can tell you are responding more out of emotion than out of actually reading what he wrote. Using that distortion figure as a benchmark(which is actually the industry standard) actually makes sure you are not overdriving the sub, which would skew the results.



Then you don't understand the scientific principle. Very well.

rw

His paper passed peer review, so what you have to say about is means nothing. Refute it by doing your own testing, and submit your own white paper, or grow up and accept the results. It is that simple. Your bad mouthing him(or me) is not going to change the fact that he is published, has been peer reviewed, and you haven't.

Sir Terrence the Terrible
08-31-2010, 08:19 PM
Well if he did it to debunk the "stoned" theory of the four subs of the then I would say it was a worthy effort. Perhaps Welti was the Amsterdam dropout in this case?

Actually no, his paper touched on a different subject matter than Nousiaine and Toole's. His paper was about sub placement without exciting the rooms modes and nodes(hence the mid wall placement).It was not about getting the best performance from your sub. It was the online press, and the average online joe who took the paper as a challenge to Nousaine and Toole's work. So if anyone was smoking something, it was everyone BUT Nousaine and Toole.


FWIW; I STILL think a lot of cannabis is consumed in this particular form of research.

LOLOL, ahh come on Geoff.

Geoffcin
09-01-2010, 02:23 AM
Why would you assume their curves would be the same? The jump from the F-1800 generation to the DD-18 is huge when it comes to performance. The servo and limiters are adjustable with the DD-18, and the F-1800 had no such benefit. The driver was improved(and is different from the F-1800), as was the cabinet, the amp is a DASH amp as oppose to a B class amp with the F-1800.

There is so much that is different from these two subs that one cannot use the other to classify performance levels.

I would assume a difference, but not to the point where the curve is lopsided. ALL subs have higher output above 20Hz, even 18" monsters. The f1800 didn't have some "magic driver" response that allowed it to produce it's highest output at 12Hz, hence the paper you've quoted is obviously flawed in at least that parameter.

E-Stat
09-01-2010, 05:06 AM
If he used a 10% distortion figure as a benchmark, how in the hell would he be overdriving a sub? I
Very good question you ask about your own comments. I would be very interested in your explaining what you mean by:

"and higher distortion from mid wall positioning.
and the distortion of the driver is increased
and with that penalty comes more distortion"

Which is it? He used the 10% distortion figure (as you find in the graphs) or he overdrove them to higher levels.


His paper passed peer review...
That and a buck will still get you a cup of coffee. So did E. Brad Myers when he *proved* that you cannot hear the difference between 44.1 and SACD.and failed to provide details of his test as well.

rw

Sir Terrence the Terrible
09-01-2010, 09:42 AM
Very good question you ask about your own comments. I would be very interested in your explaining what you mean by:

"and higher distortion from mid wall positioning.
and the distortion of the driver is increased
and with that penalty comes more distortion"

Which is it? He used the 10% distortion figure (as you find in the graphs) or he overdrove them to higher levels.

Jeeze, I thought you were such an audio expert, these mundane terms would be common knowledge to you. The concept is pretty simple, and I have already explained it once already(now do you get why I have to repeat things over and over to you). A sub tucked into a corner benefits from 9db gain from boundary reinforcement from the surrounding walls. You get that gain without even touching the volume button, becauase the driver is efficiently couple with the surrounding surfaces. The gain increases as the frequency decreases. A mid wall placement only benefits from a 3db gain, because the only wall it "see's" is the floor. It's gain does not increase with the decrease in frequency because it only couples efficiently with the floor, and no other boundary. If I am going to reproduce a 25hz sinewave at 100db, that would be far easier to do with a corner loaded sub, than one sitting in the middle of the wall because of the gain afforded from corner placement. That means because of the gain, the speaker amps and driver work less to acheive the 100db goal. A speaker sitting mid wall has no effiecient gain to help it acheive 100db at 25hz, so the burden is fully on the driver and amp to do the heavy lifting. As the frequency decreases, the driver has to move further, and the amp has to push harder to get to 25hz, let alone produce the 100db. Hence, an increase in distortion. What he is saying is the 10% distortion benchmark is reached quicker with the mid wall placement, than it was for the corner placement. The corner placed sub was louder at lower frequencies before reaching 10% distortion than the mid wall placement was. At no time did he overdrive the sub(for the second damn time)



That and a buck will still get you a cup of coffee. So did E. Brad Myers when he *proved* that you cannot hear the difference between 44.1 and SACD.and failed to provide details of his test as well.

rw

But was Myers white paper supported by other white papers? Apparently not. But Nousaine white paper coincides with Floyd Toole's white paper, and both have remained unchallenged all the way till now.

Nousiane did provide details in his white paper, so your insistence that he didn't is just plain wrong. What you are reading on his website is an excerpt from that white paper(I have had to repeat that multiple times as well).

E-Stat
09-01-2010, 10:14 AM
A sub tucked into a corner benefits from 9db gain from boundary reinforcement from the surrounding walls...
Obviously, along with additional coloration.


What he is saying is the 10% distortion benchmark is reached quicker with the mid wall placement, than it was for the corner placement.
If you undersize the subs and push them too far, that would be correct. Overdriving will most certainly increase distortion. His output level measurement, however, were performed at the same distortion level for each test. Which is why your repeated comments about added distortion are irrelevant.


But Nousaine white paper coincides with Floyd Toole's white paper, and both have remained unchallenged all the way till now.
There is no challenge to the assertion that placing subs in the corner provide higher output if you don't care about optimum sound quality. Yet, Noussaine doesn't understand the scientific principle of providing details required to replicate a test.


Nousiane did provide details in his white paper, so your insistence that he didn't is just plain wrong.
By all means, replace speculation with data. The paper on Nousaine's website that has been linked to in this thread multiple times most certainly does not. Best of luck to you providing substance to your claim.

rw

Sir Terrence the Terrible
09-01-2010, 12:56 PM
Obviously, along with additional coloration.

You are going to get it anyway if a sub touches any surface. I already said this before.



If you undersize the subs and push them too far, that would be correct. Overdriving will most certainly increase distortion. His output level measurement, however, were performed at the same distortion level for each test. Which is why your repeated comments about added distortion are irrelevant.

An 18" velodyne sub is hardly an undersize sub, so that comment is a pile of BS. The comment on added distortion comes from the fact that he tried to get the subs output to be identical at their respective positions, and doing so drove the mid wall sub well past 10% - hence the added distortion.



There is no challenge to the assertion that placing subs in the corner provide higher output if you don't care about optimum sound quality. Yet, Noussaine doesn't understand the scientific principle of providing details required to replicate a test.

Buy the AES paper, and you will see that he did indeed provide all the details that anyone needs. Optimum sound quality comes from equalizing the sub once all response deviations are identified. It is alot easier to equalize a sub placed in a corner, than one sitting away from walls, or even at mid wall position. I know this for a fact. This is why Toole and Nousaine recommends corner placement. You are sure not going to get optimum sound quality by overdriving a sub trying to reproduce deep bass at high levels.



By all means, replace speculation with data. The paper on Nousaine's website that has been linked to in this thread multiple times most certainly does not. Best of luck to you providing substance to your claim.

rw

Why don't you just buy the white paper, since all of your assumptions(because that is what they are) are based out of total ignorance so far. Since you are challenging the data, it is up to you to provide evidence that refutes his paper. Good luck with that!

Sir Terrence the Terrible
09-01-2010, 01:02 PM
I would assume a difference, but not to the point where the curve is lopsided. ALL subs have higher output above 20Hz, even 18" monsters. The f1800 didn't have some "magic driver" response that allowed it to produce it's highest output at 12Hz, hence the paper you've quoted is obviously flawed in at least that parameter.

It did have room gain though, so there is nothing flawed in that paper. Since you are assuming, then it is your comments that are flawed.

In reading Richard Hardesty measurement of the sub(which by the way were pretty close to J. Johnsons), the limiters and servo are pretty agressive in the F-1800, and they are used to keep the distortion levels of the sub below 5%, which obviously would restrain the sub total output.

I would suggest you measure one using the 10% distortion benchmark, that way you can challenge the data out of experience instead of out of assumption.

E-Stat
09-01-2010, 01:40 PM
I already said this before.
Like the Oracle at Delphi? :)


The comment on added distortion comes from the fact that he tried to get the subs output to be identical at their respective positions, and doing so drove the mid wall sub well past 10% - hence the added distortion.
I didn't realize he was stupid enough to not understand that the corner sub could always play louder with its added gain. Hint: select a sub that will play sufficient levels at whatever distortion threshold you desire or keep your gain levels in check. Which is what the graphs reflect.


...since all of your assumptions(because that is what they are) are based out of total ignorance so far.
My observations are based entirely on reading his paper called "Multiple Subwoofers" found here. (http://www.nousaine.com/nousaine_tech_articles.html) You might want to actually follow the link and read it.


Since you are challenging the data, it is up to you to provide evidence that refutes his paper. !
The only thing I refute is your assertion that placing a sub anywhere other than a corner necessarily increases distortion. It does not. It is driving a sub past its optimum range which increases distortion. If you're smart enough to not clip your amp, then you should do OK with your subs, too. :)

rw

Geoffcin
09-01-2010, 02:56 PM
It did have room gain though, so there is nothing flawed in that paper. Since you are assuming, then it is your comments that are flawed.

In reading Richard Hardesty measurement of the sub(which by the way were pretty close to J. Johnsons), the limiters and servo are pretty agressive in the F-1800, and they are used to keep the distortion levels of the sub below 5%, which obviously would restrain the sub total output.

I would suggest you measure one using the 10% distortion benchmark, that way you can challenge the data out of experience instead of out of assumption.

I have the same type of servos on my subs, (which are smaller) and I got a 107dB reading at approximately the same distance that he got a 90dB reading. My conclusion, and I will stand by it 100%; is that either his dB meter was in error (the most likely scenario IMHO), or his sub was broken. There's no was that sub puts out more dB under 20Hz than above.

Sir Terrence the Terrible
09-01-2010, 03:21 PM
I have the same type of servos on my subs, (which are smaller) and I got a 107dB reading at approximately the same distance that he got a 90dB reading. My conclusion, and I will stand by it 100%; is that either his dB meter was in error (the most likely scenario IMHO), or his sub was broken. There's no was that sub puts out more dB under 20Hz than above.

Geoff,
Nowhere in your posts have you stated a distortion figure, nowhere(Hardesty, Johnson, and Nousiane did). So for you to say that you are standing by a non benchmark figure, suggests nothing when the industry uses 10% figures as that benchmark. You also haven't provided anything in the way of room size, so that can be compared to both R. Hardesty's and J. Johnson's room. You also have not mentioned the measuring system you used(That is important so one can distinguish who's is accurate, and who's is probably not). You haven't stated where your subs are positioned as well, so for you to stand by all of these information holes is quite puzzling to me. The other guys that have measured this subwoofer have addressed all of these issues, and their results are quite frankly very close.

Sir Terrence the Terrible
09-01-2010, 04:09 PM
Like the Oracle at Delphi? :)

I am not impressed by 'cuteness" being displayed by a grown man.



I didn't realize he was stupid enough to not understand that the corner sub could always play louder with its added gain. Hint: select a sub that will play sufficient levels at whatever distortion threshold you desire or keep your gain levels in check. Which is what the graphs reflect.

Perhaps he did and was just countering the mis-application of Welti white paper. He selected the sub that was(at the time) one of the most powerful LF producers on the market. Part of his methodology was to remove distortion as a limiting factor within the test. In others words, the test was not designed to overdrive the sub, but to get the maximum output with in the industry standard of 10% within that room. In his white paper he measured room more to the size of the average listening room according to a survey. While the SPL levels were higher for both positions in those size rooms, the LF penalty remained for the mid wall position. When trying to equalize the level of the subwoofers in their respective places, he still found a higher measured distortion level with the mid wall placement. This is why having the white paper(as opposed to the pre-test evaluation missing the subwoofer model and the additional rooms) is valuable when trying to engage in this discussion. You are currently blindly fishing for flaws based on excerpts, which causes your assumption gear to go into overdrive.



My observations are based entirely on reading his paper called "Multiple Subwoofers" found here. (http://www.nousaine.com/nousaine_tech_articles.html) You might want to actually follow the link and read it.

Bring the assumption gear into low, you are assuming I have not read it, I posted it in the first place..duh!. As I have said for the fourth time now(this is why I repeat stuff to you), the is a just an exerpt to his formal white paper. He did say this:(paraphrased)

This experiment should be replicated in a 20x15x8' room(Found to be the most common room size in North America based on a 250 person survey) helping to ensure a wider application

In his white paper he did exactly that, and outlined in great detail his measureing techniques, his equipment, the sub, and the measurements of mutliple rooms to support his assertions.



The only thing I refute is your assertion that placing a sub anywhere other than a corner necessarily increases distortion. It does not. It is driving a sub past its optimum range which increases distortion. If you're smart enough to not clip your amp, then you should do OK with your subs, too. :)

Well, the results of Nousiane white paper disputes your assertions, and he has measurements to prove it, and you do not. So who I am to believe....the arm chair judge, or the guy who actually did the experiment, was judge by his peers(of which you are not), and passed the judgement unrefuted.

The amount of power required from the amp at any given frequency within the 80-20hz region is substantial. When you put a subwoofer in a place where the amp does not have to work as hard to achieve X level, that sub will have lower distortion than a sub that must rely solely on the abilities of the amp and driver to reach that same X level. This is common knowledge for subwoofer placement, and you don't seem to know this. Interesting...

When a sub can rely on a 9db boost from corner placement at its lowest operating point without touching the volume control (which means less stress on the amp, and shorter excursions from the driver which does not increase distortion), it will not have to work as hard as a subwoofer that has no boost at its lowest operating point(and would require a lot of power from the amp, and long excursion from the driver). This is also pretty common knowledge as well, and it is interesting you don't know this.

There are two things you can do here that will educate you profoundly on the interaction between boundaries and subwoofer. Rent a RTA(with at least 1/12 resolution), a tone generator, and a high quality lab grade microphone - I use the MLSSA system from DRA labs. Secondly, go to your sub and move it into a corner(if it is not already there), and measure the frequency response, the distortion levels, and the reference output(the loudest the sub goes before 10% distortion). Move the sub to the center of the front wall, and do the same thing. Record the results, and see if there is a LF penalty at frequencies below 40hz(if your sub can reach that low), and see if you try and match volume levels of the different positions if distortion rises below 40hz. If you results are dramatically different from Toole's and Nousaines(we are talking overall trends, not minutia that you like to bloat up), them submit a white paper that challenges theirs to AES committee for peer review.

Anything short of that is a bunch of hot air that is nothing more than conjecture, assumption, untested personal theory. If you are so strong in your convictions, test them out instead of theorizing about them. The reason I agree with both publishers is because I have experienced their theory in real life while working as a installer specializing in audio system calibration and voicing. So there is the challenge, assume or educate, the choice is yours.

E-Stat
09-01-2010, 04:15 PM
Well, the results of Nousiane white paper disputes your assertions, and he has measurements to prove it, and you do not.
Sorry, I'll have to let the farce end here. Only an idiot doesn't understand clipping or overdriving a speaker. Smart people operate speaker and amps within their designed range.


The amount of power required from the amp at any given frequency within the 80-20hz region is substantial. When you put a subwoofer in a place where the amp does not have to work as hard to achieve X level, that sub will have lower distortion than a sub that must rely solely on the abilities of the amp and driver to reach that same X level. This is common knowledge for subwoofer placement, and you don't seem to know this. Interesting...
You: Doctor, it hurts when I crank my subwoofers to high distortion levels.
Dr.: Don't do that.

Your comments remind me of warning labels you find on irons that say: Don't wear garment while using this product. I enjoy your humor. :)

rw

Sir Terrence the Terrible
09-01-2010, 04:17 PM
Sorry, I'll have to let the farce end here. Only an idiot doesn't understand clipping or overdriving a speaker. Smart people operate speaker and amps within their designed range.


You: Doctor, it hurts when I crank my subwoofers to high distortion levels.
Dr.: Don't do that.

I enjoy your humor. :)

rw

Exactly what I thought.....all hot air, assumption, and no action.

E-Stat
09-01-2010, 04:46 PM
...and no action.
If you discover that you are overdriving an component into high distortion, what action would you take?

A. Write a paper about it
B. Add equalization boost
C. Turn it down

rw