Titanic Mkiii 15"

[L.J.]

This has got to be one of the most effective home theater upgrades you can do.
I have a lot of explaining to do when people walk in and see 12 big panels around my room hanging on walls...my Dad makes fun of me and my inlaws think I'm crazy....they just don't understand.

My wife thinks they look good and even suggested I put up a few more. She's even open to adding bass traps. I did get a raised eyebrow from my sister though.

I think they'll make a nice conversation piece when company is over.

I still have to calibrate my sub and do some room measurements, but so far everything is sounding extremely well. This Titanic has some serious BANG and can take over the room easily. I'm VERY happy with this sub.

I noticed in some pics at ATS that some were using bass traps with a square shape to them. It almost looked like a stack of foams bricks. I liked the look of those rather than the triangular foam wedges. Do you have any idea where I can find those?

[kexodusc]

My wife thinks they look good and even suggested I put up a few more. She's even open to adding bass traps. I did get a raised eyebrow from my sister though.

I think they'll make a nice conversation piece when company is over.

I still have to calibrate my sub and do some room measurements, but so far everything is sounding extremely well. This Titanic has some serious BANG and can take over the room easily. I'm VERY happy with this sub.

I noticed in some pics at ATS that some were using bass traps with a square shape to them. It almost looked like a stack of foams bricks. I liked the look of those rather than the triangular foam wedges. Do you have any idea where I can find those?

(hey, those beige/natural panels look just like my small panels - that's the color I got)

LJ,

Those look to me like big dense foam blocks. You are better off (cost and performance wise) to stick with Rigid Fiberglass. You'll want the OC705 or equivalent, 6lb density fiberglass - or use twice as much OC703. Bass traps are expensive.
Even another 4' X 2' panel across your corners would produce good results...double up the fiberglass thickness (or more).

I like the corner trap designs:
http://forum.studiotips.com/viewtopic.php?t=535
and
http://forum.studiotips.com/viewtopic.php?t=534

I just made narrow, tall panels, chamfered the edges so they fit in the corner flush, about 12 wide for my corner traps. I will go the corner "chunk" route some day...but no rush, the BFD and the corner traps I do have yield great results now, so I'm not as motivated to tackle that project.

(edit - oh yeah, this place here sells foam corner treatment for decent prices:
http://foamforyou.com/foam_corner_kits.htm
You can find the blocks down the page some...
Here's another - a
http://www.foambymail.com/CornerSolutions.html
gain, not quite as good as Auralex and the super high-end foams, but for this price you can buy two or three times as much).

[Scott R. Foster]

snip...

...You are better off (cost and performance wise) to stick with Rigid Fiberglass. You'll want the OC705 or equivalent, 6lb density fiberglass - or use twice as much OC703. Bass traps are expensive.Even another 4' X 2' panel across your corners would produce good results...double up the fiberglass thickness (or more).

I like the corner trap designs:
http://forum.studiotips.com/viewtopic.php?t=535
and
http://forum.studiotips.com/viewtopic.php?t=534

snip

(edit - oh yeah, this place here sells foam corner treatment for decent prices:
http://foamforyou.com/foam_corner_kits.htm
You can find the blocks down the page some...
Here's another - a
http://www.foambymail.com/CornerSolutions.html
gain, not quite as good as Auralex and the super high-end foams, but for this price you can buy two or three times as much).

Hi Kex:

Thanks for the links to our DIY designs, but I wanted to tweak your advice a little if you don't mind.

1) 703 need not be doubled in thickness versus 705 to achieve similar performanace... in fact for a properly proportioned broadband device 703 is a superior choice [costs half as much / weighs half as much/works as good or better]. The reason is that the gas flow resistance of 703 is just about optimal for a 4 to 6" panel, and anything thinner [regardless of what type of foam / mineral fiber you use] will not perform at lower frequencies. You can directly compare the manufacturer's absorption specs for 703, 705 and many other flavors of mineral fiber here:

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

2) Acoustic foam is a perfectly good choice for porous absorber desgin - but the material is not cheap. If you find an extremely cheap price for foam panels, there is a good chance it isn't acoustic grade foam and therefore no bargain - as it just won't work like the real stuff will. More on the foam versus mineral fiber here:

http://forum.studiotips.com/viewtopic.php?t=48

PS: them's some nice looking panels... good job matching the couch

[kexodusc]

Hi Kex:

Thanks for the links to our DIY designs, but I wanted to tweak your advice a little if you don't mind.

1) 703 need not be doubled in thickness versus 705 to achieve similar performanace... in fact for a properly proportioned broadband device 703 is a superior choice [costs half as much / weighs half as much/works as good or better]. The reason is that the gas flow resistance of 703 is just about optimal for a 4 to 6" panel, and anything thinner [regardless of what type of foam / mineral fiber you use] will not perform at lower frequencies. You can directly compare the manufacturer's absorption specs for 703, 705 and many other flavors of mineral fiber here:

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

Hi Scott, it's a real pleasure having someone from studiotips visit our little corner of the world wide web...I've been a long time lurker there...I know your site's been extremely informative for me. Just curious how you ended up here?

I think you've just echoed the advice I've tried to give for the most part. Let me ask you though, since LJ was discussing the foam blocks used in a corner in his post, which I can only reasonably assume is to act as a bass trap rather than a broadband absorber, isn't the 705 actually a better absorber below 125 Hz than the 703? At higher frequencies I'm less concerned about the performance differences in the corners between 705 and 703, but say at 40-80 Hz in particular? Maybe the 703 at 6" or so effectively matches the 705 performance? I sort of envisioned a 2" to 4" or so diagonal panel across the corner? Just trying to find the optimal cost/performance balance here....

2) Acoustic foam is a perfectly good choice for porous absorber desgin - but the material is not cheap. If you find an extremely cheap price for foam panels, there is a good chance it isn't acoustic grade foam and therefore no bargain - as it just won't work like the real stuff will. More on the foam versus mineral fiber here:

http://forum.studiotips.com/viewtopic.php?t=48

Guess the ol' "buyer-beware" warnings applies to acoustic foams, too....

Hope to see you stick around in some fashion, thanks again!

[L.J.]

Gremlins! That's it, I must have gremlins. Someone keeps turning up my sub. I've turned it down 3 times already only to have it get too loud again an hour or so later. Is this a break in thing?
Half way through last night the sub seemed to be over powering my system again. But this time, instead of turning it down, I started playing with the parametric EQ. Haven't stopped by Rat Shack to pick up a meter yet, but never let it be said that anything will stop me. Equipment, knowledge, who needs it? Here's what I did. With the gain turned up to +4db I started turning the dial up from 18htz. When I got to about 60htz the boominess more than doubled. So I left the dial at 60htz and turned the gain/defeat down to -3db. Now it sounds great again. Doesn't overpower the system, but still hits like a ton of bricks when it is supposed to. Maybe some day I'll get off my lazy ars and ride the 5 miles down the road to the Shack. But till then, I'm a very happy man.

Hey GM, have you had a chance to calibrate your sub yet?

I finally pulled out my SPL meter and Rives test tones CD and was able to really get my sub dialed in. Take a look at these before results:



The blue line is my first measurement. The gray is I guess my halfway point. I did alot more measurements, but only put a few on graph.

As you can see I had a HUGE peak at around 40/50hz. I was unable to properly set my sub level because of it. As a result, I had to set my sub's level really low. I knew it was there but the room measurements confirmed it. I was able to cut the peak down using the sub's eq. Cutting that one peak down made a night and day diff for my bass. The improvement was crazy. The sub blended with the rest of my system so much better. I was able to go in and properly set my level now because the peak was not screwing everything up. The bass is deep,but so freakin' smooth.

Here are my results now:



As you can see, the response is a heck of alot smoother now. I still have a peak at 90hz and a few bumps that I plan on taking care of it in the future(can you say BFD), but for now I have some pretty decent bass. Anyways, I thought I'd share my results with you and pressure you to spend some $$$.

[GMichael]

Oh! Very promising results. Congrats on a job well done. Doesn't that peak at 90 have more to do with your mains? What do you have the crossovers set at?

No, haven't done mine yet. Still sounds great though. Just doing it by ear I was able to get rid of what seemed to be a peek at 60. I have put a spending freeze on all purchases until further notice. Don't want to buy more new stuff just before I have to move it, again. May very well have to leave some new stuff behind as it is.

[L.J.]

Oh! Very promising results. Congrats on a job well done. Doesn't that peak at 90 have more to do with your mains? What do you have the crossovers set at?

No, haven't done mine yet. Still sounds great though. Just doing it by ear I was able to get rid of what seemed to be a peek at 60. I have put a spending freeze on all purchases until further notice. Don't want to buy more new stuff just before I have to move it, again. May very well have to leave some new stuff behind as it is.

Move it????

Yep, it's the mains. My xover is set to 80hz. I'm gonna see what happens when I change it to 60hz.

[kexodusc]

Move it????

Yep, it's the mains. My xover is set to 80hz. I'm gonna see what happens when I change it to 60hz.

LJ. I'm curious to learn what happens.

What size is your room (w x h x d)? Any 19 ft-ish dimensions by chance? I have a feeling this could be a room mode issue, but you might also try moving the speakers further out from the wall or tinkering with sub placement.

Setting the XO lower could make it worse. If your receiver has a 24 dB/octave filter, you're moving the cut in the 90 Hz region further away.

[L.J.]

Kex, I'll try to get to the measurements this weekend.

My speakers are about 1 1/2' off the wall. Boy, you shoulda seen my wife's face when I said something about pulling em out further.

The room is a living/dining combo room and then it's connected to the kitchen with only a bar separating the two rooms. The kitchen is then open to the front room with only a half wall separating those two rooms. The room is 14x24. The ceiling starts out at 8' and then slopes up to 11'. My TV/speakers are on the long wall.

[L.J.]

LJ. I'm curious to learn what happens.

What size is your room (w x h x d)? Any 19 ft-ish dimensions by chance? I have a feeling this could be a room mode issue, but you might also try moving the speakers further out from the wall or tinkering with sub placement.

Setting the XO lower could make it worse. If your receiver has a 24 dB/octave filter, you're moving the cut in the 90 Hz region further away.

Well I did a few measurements and using a 60hz xover causes a huge dip(-9) right at the xover point. The peak at 100 was still there. I tried playing tones at different volumes and had the same results each time.

[kexodusc]

Well I did a few measurements and using a 60hz xover causes a huge dip(-9) right at the xover point. The peak at 100 was still there. I tried playing tones at different volumes and had the same results each time.

Yeah, it's definitely looking more like a room induced peak at 100 Hz...don't feel bad, I have one around there too.
I did some calculations based on your room measurements, assuming your room to be rectangularish....you have room modes at 94 and 117 Hz (resulting from the 24 ft dimension), 80, and 121 Hz (from 14 ft) and some nasties in the 100 to 125 Hz range from that 9-11 ft slanted roof.

That's not uncommon (and not unlike mine, my room is 24 ft long too!) , but it's a lot of activity in that 90-120 Hz range which is causing you the grief. They should be especially prominent at the 110-120 Hz area...have you tested that high? And again 250Hz and 300-400Hz where lots of multiples are close together, though your room treatment might be softening the last few somewhat, and there's not really much you can do there (and you may not notice it as much?).
This is just the theory based numbers, the presence of your room treatement, furniture, and room architecture is likely to shift those all a bit, so precise peaks are hard to predict, but we're definitely in the ballpark.

You might find changing the sub placement or speaker proximity has some effect, though I expect it will be small. Ideally, you'd have some room treatment to soften the blow somewhat in that 100 Hz -125 Hz range. Even then I'm not sure how much better corner traps would make it. That frequency area is kind of nice though, lower bass is absorbed less by bass traps, and higher frequencies become more directional so their level at the listening position is not altered as much.

I really needed to put a cut on my 90 Hz peak with the BFD, it has a wider Q, so it just filters the sub lower. I flip back and forth between an 80 Hz, and 100 Hz XO for my sub.
Despite popular belief, the higher XO isn't terrible, and my sub at least doesn't really start becoming directional until 100-110 Hz or so. If I ever get around to building the 2nd one, that should help somewhat. I have corner traps that help a bit, but I live with some mess at 115 and especially 140 Hz right now.

Oh well.

[GMichael]

Yeah, it's definitely looking more like a room induced peak at 100 Hz...don't feel bad, I have one around there too.
I did some calculations based on your room measurements, assuming your room to be rectangularish....you have room modes at 94 and 117 Hz (resulting from the 24 ft dimension), 80, and 121 Hz (from 14 ft) and some nasties in the 100 to 125 Hz range from that 9-11 ft slanted roof.

That's not uncommon (and not unlike mine, my room is 24 ft long too!) , but it's a lot of activity in that 90-120 Hz range which is causing you the grief. They should be especially prominent at the 110-120 Hz area...have you tested that high? And again 250Hz and 300-400Hz where lots of multiples are close together, though your room treatment might be softening the last few somewhat, and there's not really much you can do there (and you may not notice it as much?).
This is just the theory based numbers, the presence of your room treatement, furniture, and room architecture is likely to shift those all a bit, so precise peaks are hard to predict, but we're definitely in the ballpark.

You might find changing the sub placement or speaker proximity has some effect, though I expect it will be small. Ideally, you'd have some room treatment to soften the blow somewhat in that 100 Hz -125 Hz range. Even then I'm not sure how much better corner traps would make it. That frequency area is kind of nice though, lower bass is absorbed less by bass traps, and higher frequencies become more directional so their level at the listening position is not altered as much.

I really needed to put a cut on my 90 Hz peak with the BFD, it has a wider Q, so it just filters the sub lower. I flip back and forth between an 80 Hz, and 100 Hz XO for my sub.
Despite popular belief, the higher XO isn't terrible, and my sub at least doesn't really start becoming directional until 100-110 Hz or so. If I ever get around to building the 2nd one, that should help somewhat. I have corner traps that help a bit, but I live with some mess at 115 and especially 140 Hz right now.

Oh well.

Wow. That's just what I was going to say.

[L.J.]

I tested up to 160hz. There's peaks at 125 & 160 but not as bad as the one at 100hz. I toyed with sub/speaker position but I'm pretty satisfied with my results. Besides, that freakin' Titanic is heavy

I'd like to do some measurements after running my avr's room eq setup, but I can't get it to take any correct measurements. It keeps setting all my levels(except the sub) to +12db. I know they don't eq well in the lower freq, but what's considered low?

One problem I still have is echo. Not sure if that affects the lower freq or not. The room is a living/dining room. I only treated the HT side of the room. The dining side has the highest ceiling point and alot of bare wall still.

[kexodusc]

I tested up to 160hz. There's peaks at 125 & 160 but not as bad as the one at 100hz. I toyed with sub/speaker position but I'm pretty satisfied with my results. Besides, that freakin' Titanic is heavy

I'd like to do some measurements after running my avr's room eq setup, but I can't get it to take any correct measurements. It keeps setting all my levels(except the sub) to +12db. I know they don't eq well in the lower freq, but what's considered low?

One problem I still have is echo. Not sure if that affects the lower freq or not. The room is a living/dining room. I only treated the HT side of the room. The dining side has the highest ceiling point and alot of bare wall still.

That is bizarre...the EQ's of the auto-setups on a lot of receivers are hit and miss, some are terribly fussy (though they're all much better than the first few years they were out) but I've never heard of one that didnt' get the delays and levels bang on (except for subs). Everytime I've compared them to an SPL meter (not just my own system) they've been accurate. Is there much background noise where you are?

The low frequencies for the EQ's are usually below 100 Hz, sometimes as low as 80 Hz.
Keep in mind, these things are imprecise because the microphone is in a small fixed location. A few inches either way can produce quite a different response. Most of the time it should be close though. Try running it several times when nobody else is home.

[L.J.]

That is bizarre...the EQ's of the auto-setups on a lot of receivers are hit and miss, some are terribly fussy (though they're all much better than the first few years they were out) but I've never heard of one that didnt' get the delays and levels bang on (except for subs). Everytime I've compared them to an SPL meter (not just my own system) they've been accurate. Is there much background noise where you are?

The low frequencies for the EQ's are usually below 100 Hz, sometimes as low as 80 Hz.
Keep in mind, these things are imprecise because the microphone is in a small fixed location. A few inches either way can produce quite a different response. Most of the time it should be close though. Try running it several times when nobody else is home.

My mic has always been accurate in the past. It has to be the room that's messing things up. Although all the levels are set to 12db, the delay is perfect everytime . It's strange because my surrounds are only 6ft from the listening position. Since the room is so large the levels have to be set kinda high but not 12db. I have no problems using my RS meter. I have also played the avr tones at higher volumes hoping I could get a reading but all levels are still set to 12db.

There is no background noises. I usually wait until the house is empty. My wife hates test tones for some reason

[kexodusc]

My room is 20 X 24, I'm about 10 feet from all speakers, except the rears, which are 8.5 ft behind me or so...I dont' get any pair maxed out that high. The absolute number (+12) doesn't matter if the level you'd set it to manually with your RS meter is the same for all speakers. But if some speakers should be higher or lower than the others, maybe the best thing to do is not use the auto-setup. Though, if the eq is doing it's job right, you should be able to manually alter the levels yourself.

[L.J.]

My room is 20 X 24, I'm about 10 feet from all speakers, except the rears, which are 8.5 ft behind me or so...I dont' get any pair maxed out that high. The absolute number (+12) doesn't matter if the level you'd set it to manually with your RS meter is the same for all speakers. But if some speakers should be higher or lower than the others, maybe the best thing to do is not use the auto-setup. Though, if the eq is doing it's job right, you should be able to manually alter the levels yourself.

I'll probably run the auto set up and check the levels with my meter to see what's going on.

My avr also has a manual eq that I tried toying with but none of the adjustment I made had any affect on the response when taking room measurements.


Hmm....a thought just popped in my head Does the tweaking ever end

[Rich-n-Texas]

I'll probably run the auto set up and check the levels with my meter to see what's going on.

My avr also has a manual eq that I tried toying with but none of the adjustment I made had any affect on the response when taking room measurements.


Hmm....a thought just popped in my head Does the tweaking ever end

This thread's got my head spinning!!!

[GMichael]

This thread's got my head spinning!!!

Doing a little thread revival these days?

[Rich-n-Texas]

Might as well. Even your post count is down this week...

[GMichael]

Might as well. Even your post count is down this week...

There just hasn't been much to post about. We need another party.

[Rich-n-Texas]

I asked you more questions in my DVD-A Monitor thread, but as usual you ignored me.

[GMichael]

I asked you more questions in my DVD-A Monitor thread, but as usual you ignored me.

Huh? I wouldn't ignore you Tex. If I didn't write back, it was because I missed your question. Where is this thread with the question in it?

[E-Stat]

I have a lot of explaining to do when people walk in and see 12 big panels around my room hanging on walls...my Dad makes fun of me and my inlaws think I'm crazy....they just don't understand.

I get the same reaction with the main system. What are those big black things? And why do you have all those cylinders in the room?

rw

[Rich-n-Texas]

Monitor for DVD-A's

I need to know how you converted from composite or S-Vid to VGA...