Choice of insulation & fabric for diy panels?

[spaceape]

Hi all. I hope that you're having as much fun with your home theaters as i am.

I have a few concerns that i need to have answered.

1. In my home theater i've added no corner traps or the like because of limited space. Instead i've added high density insulation slabs in all of my panels. Will this be a decent compensation or do very little too help with lower frequencies absorption since most of those frequencies tend to gather in and around corners?

2. For all of my panels i've used microsuede fabric which haven't got very good absorption for the very high frequencies. Im mostly concerned that this combined with the rather high (100kg/m3) density of the rockwool will result in bad performance for my 2" panels. That being said i have quite a lot of them so maybe it ain't too bad. Is this something i need too be concerned about?

This is an illustration of my room. The main ht is in the left half part of the picture. My couch is in the top left of the black rectangle and the speakers and screens are on the opposing wall. Take a look in my gallery to get a better idea of the room.

[Ethan Winer]

I got your PM, thanks for posting in the public forum. Though you're not making this easy.

I spent five minutes trying to find your gallery, and gave up. Please post a link. Or, better, update your drawing to show where the speakers and couch are.

Panels two inches thick are not useful for bass traps. They need to be at least four inches thick. Any fabric is fine for bass traps in corners, but absorbers at reflection points must be fully absorbent at high frequencies. So your suede is not the right choice for that location.

--Ethan

[crazyBLUE]

Originally Posted by Ethan Winer

I got your PM, thanks for posting in the public forum. Though you're not making this easy.

I spent five minutes trying to find your gallery, and gave up. Please post a link. Or, better, update your drawing to show where the speakers and couch are.

Panels two inches thick are not useful for bass traps. They need to be at least four inches thick. Any fabric is fine for bass traps in corners, but absorbers at reflection points must be fully absorbent at high frequencies. So your suede is not the right choice for that location.

--Ethan

Click on the #6 next to where it says Home Theater Gallery under his Avatar & it will take you to his gallery

[spaceape]

Sorry Ethan. Here it is. >Link<

Thank you Brent.

[spaceape]

Originally Posted by Ethan Winer

I got your PM, thanks for posting in the public forum. Though you're not making this easy.

I spent five minutes trying to find your gallery, and gave up. Please post a link. Or, better, update your drawing to show where the speakers and couch are.

Panels two inches thick are not useful for bass traps. They need to be at least four inches thick. Any fabric is fine for bass traps in corners, but absorbers at reflection points must be fully absorbent at high frequencies. So your suede is not the right choice for that location.

--Ethan

No Ethan you're right. 2" do very little as basstraps. My hope were that the 4" panels at the rear wall behind the sofa and those behind the speakers could help out as basstraps and the 2" ones too the sides of the room weren't totally unsuited in absorbing the higher frequency reflections even though they are made of owens corner 705 type insulation and microsuede fabric both things limiting it's performance in that area. The fabric is fake suede if this matters. So not leather of any kind.

A quote taken from a guy named Terry Montlick:

Guilford Anchorage does not have very good acoustical transparency. My measurements show that it attenuates more than 3 dB at 2 kHz, and about 6 dB at 8 kHz. That is at least a doubling of panel space required at these higher frequencies, compared to FR701.

"SoundSuede" fabric is similar to Anchorage in performance. Dazian Janus measures a little better, with around 2 dB attenuation at 2 kHz, but 4 dB at 8 kHz.

And some tests done by ATS Acoustics were from i got the fabric:



>Clip<

Made this short clip so that you might get an idea of how my main listening position is configured. Behind the Front, center and subs and again behind the couch i've placed 4" panels. To the right side of the couch i've placed 4x 2" panels (three under the windows and one too the right side close to the couch). Again too the left ( not much wall here this is were i stand in the clip) two 2" panel on the bottom and top of the wall right too left of the couch. Two extra 2" panels is placed even further too the left on a opposing wall.

Edited the illustration as told:



Can't i use my MultEQ Pro "before" measurements as an indicator of how badly the high frequencies is messing up the acoustics in my room? Or maybe i need too use something better like the ETF software?:

The below results are from my last calibration:

[Ethan Winer]

Originally Posted by crazyBLUE

Click on the #6 next to where it says Home Theater Gallery under his Avatar & it will take you to his gallery

D'oh!

[Ethan Winer]

Originally Posted by spaceape

And some tests done by ATS Acoustics were from i got the fabric:

Well, since you purchased acoustic materials from a commercial vendor, you should ask for their advice. They owe you the time and effort as a customer. I can tell you that your bass response would be improved greatly with thicker bass traps. And you need to measure using proper software such as Room EQ Wizard. The Audyssey display is not high enough resolution, and it doesn't show ringing which is just as important as the raw response.

--Ethan

[spaceape]

Originally Posted by Ethan Winer

Well, since you purchased acoustic materials from a commercial vendor, you should ask for their advice. They owe you the time and effort as a customer. I can tell you that your bass response would be improved greatly with thicker bass traps. And you need to measure using proper software such as Room EQ Wizard. The Audyssey display is not high enough resolution, and it doesn't show ringing which is just as important as the raw response.

--Ethan

Yes i should ask them for more information regarding their fabric. Which measurement software and microphone is in your opinion the most accurate? Im thinking of maybe investing in a kit for checking my room acoustics.

I've been pondering one last thing. Isn't higher frequencies easier too treat than the lower. In that case maybe it's okay too have a little worse absorption in the 1000hz+ area. Or am i totally wrong in this assumption?

Thank you so much for all your help. I know you're a busy man.

[Ethan Winer]

Originally Posted by spaceape

Which measurement software and microphone is in your opinion the most accurate? Im thinking of maybe investing in a kit for checking my room acoustics.

Room Measuring Primer
Comparison of Ten Measuring Microphones

Isn't higher frequencies easier too treat than the lower.

Yes!

Acoustic Basics

--Ethan

[spaceape]

Originally Posted by Ethan Winer

Room Measuring Primer
Comparison of Ten Measuring Microphones



Yes!

Acoustic Basics

--Ethan

Thank you Ethan.

I actually watched a great deal of your videos again today. Just too get the basics straight. The hard thing to remember as a novice are all of the technical words but the practicals are pretty easy to get ones head around.

Will start reading up on all of this. Looks like quite a lot but i asked for it hehe.

Just started making 2 new frames for a couple more 4" panels. I'll straddle them in the bottom rear corners behind the sofa. Then i'll have 18 acoustic panels mounted (excluding the auralex ones). Not quite like the 40 you own but your music/ht room is also larger by a fair amount. It'll do for the time being. Later i'll look at treating the rear top corners. I have wood and insulation for maybe 4 extra 2" traps but i'll have too find some room for them also. hehe.

Edit: The calibrated Behringer ECM8000 seems like a good choice for me. Not overly expensive.

[Ethan Winer]

Originally Posted by spaceape

Not quite like the 40 you own but your music/ht room is also larger by a fair amount.

Actually, I'm up to 55 panels now, but I swear the room is done and no more are needed!

--Ethan

[spaceape]

Originally Posted by Ethan Winer

Actually, I'm up to 55 panels now, but I swear the room is done and no more are needed!

--Ethan

Haha Ethan. At least we'll keep warm in the winter seasons.

Even better I just made four 4" frames. Already had one 2" made and will make the last of two 2'x 4' frames tomorrow and complete them all with rockwool and fabric.

Then it's the tri-corners turn.

Btw. Saw your pinball machines last night on your youtube channel. Very nice.