• 05-18-2010, 06:51 AM
    manlystanley
    1 Attachment(s)
    Need some pointers with room treatments
    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--Ow...nch--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/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&ppuser=276367
  • 05-18-2010, 07:14 AM
    JoeE SP9
    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.
  • 05-18-2010, 08:11 AM
    atomicAdam
    Quote:

    Originally Posted by JoeE SP9
    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.
  • 05-18-2010, 09:42 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by JoeE SP9
    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.
  • 05-18-2010, 10:19 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by manlystanley
    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--Ow...nch--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/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&ppuser=276367

    http://gallery.audioreview.com/showp...&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.
  • 05-18-2010, 10:39 AM
    manlystanley
    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/showp...&ppuser=276367
  • 05-18-2010, 10:55 AM
    atomicAdam
    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.
  • 05-18-2010, 10:58 AM
    manlystanley
    Quote:

    Originally Posted by atomicAdam
    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
  • 05-18-2010, 12:41 PM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by atomicAdam
    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.
  • 05-18-2010, 04:18 PM
    atomicAdam
    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.
  • 05-19-2010, 05:59 AM
    manlystanley
    Quote:

    Originally Posted by atomicAdam
    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--Ow...nch--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
  • 05-19-2010, 09:41 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by manlystanley
    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--Ow...nch--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.
  • 05-19-2010, 12:08 PM
    atomicAdam
    Quote:

    Originally Posted by Sir Terrence the Terrible
    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/Building...d/SoundChoice/

    I guess my measurement memory was wrong, it is only a 1/2 inch thick.
  • 05-20-2010, 08:40 AM
    manlystanley
    Quote:

    Originally Posted by Sir Terrence the Terrible
    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
  • 05-20-2010, 10:10 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by atomicAdam
    So here is a link to the stuff I found and am using from HomeDepot.
    http://www.templeinland.com/Building...d/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.
  • 05-20-2010, 12:38 PM
    manlystanley
    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
  • 05-21-2010, 05:14 PM
    Woochifer
    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.
  • 05-22-2010, 06:21 AM
    poppachubby
    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.
  • 05-24-2010, 04:28 AM
    manlystanley
    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
  • 05-25-2010, 08:30 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by manlystanley
    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.
  • 05-25-2010, 10:06 AM
    manlystanley
    Quote:

    Originally Posted by Sir Terrence the Terrible
    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/s...ad.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
  • 05-26-2010, 02:28 AM
    manlystanley
    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/foru...-thread-7.html

    Best Regards,
    Stan
  • 05-28-2010, 07:33 AM
    manlystanley
    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
  • 07-24-2010, 12:28 PM
    manlystanley
    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
  • 07-24-2010, 07:28 PM
    Sir Terrence the Terrible
    Congrats young fella, now lets see some pics when you are done. I can't wait!