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**raZorTT** · **07-26-09, 06:45 AM**

I've been trying to work out my treatments based on things bpape has mentioned and things that i've read in some of Prof's and cinema mad's threads.

Here is a picture of what i'm currently thinking.

Theatre treatments

Based on what I could find going through the various threads, Bradfords Ultratel is the most suitable insulation for treatments on the sidewall and rear walls. The rear walls (slightly different colour) should have an FSK or equivalent facing to keep the rear a little lively (thanks bpape!). I had planned for the sides and rear to be 25mm (1") thick.

What about the screen wall? Is that supposed to absorb as much as possible? Is Ultratel the most suitable for that? I had planned on the screen wall being 50mm (2") thick.

Are the superchunk style corner bass traps more efficient that hanging full sheets in the corner with an air gap? I had always planned to do the superchunks but some of the descriptions of corner traps have made me wonder.

I noticed cinema mad mention quietel in his bass traps thread. Would this be better than ultratel as the superchunks?

Cheers,
Simon

**Prof.** · **07-26-09, 06:44 PM**

Quote:

raZorTT wrote:

I've been trying to work out my treatments based on things bpape has mentioned and things that i've read in some of Prof's and cinema mad's threads.

Here is a picture of what i'm currently thinking.

Theatre treatments

Based on what I could find going through the various threads, Bradfords Ultratel is the most suitable insulation for treatments on the sidewall and rear walls. The rear walls (slightly different colour) should have an FSK or equivalent facing to keep the rear a little lively (thanks bpape!). I had planned for the sides and rear to be 25mm (1") thick.

What about the screen wall? Is that supposed to absorb as much as possible? Is Ultratel the most suitable for that? I had planned on the screen wall being 50mm (2") thick.

Simon,

I would be inclined to do it the other way round..
Put the 1" thick Ultratel across the front wall..and the 2" thick on the side and back walls..

Quote:

Are the superchunk style corner bass traps more efficient that hanging full sheets in the corner with an air gap? I had always planned to do the superchunks but some of the descriptions of corner traps have made me wonder.

There seems to be two schools of thought on this..Some say chunks are best , and others say flat panels across the corners...
I have 6" thick panels across the corners and they do a good job..

I would suggest that what Jason has done would be a very effective trap..
From what I understand, he's used 4" thick Ultratel with a 2" thick Quietel panel to make up a 6" corner trap..

Also, your sketchup isn't showing any rear corner traps..Is this just an oversight?

**raZorTT** · **07-26-09, 07:45 PM**

Quote:

Prof. wrote:

Simon,

I would be inclined to do it the other way round..
Put the 1" thick Ultratel across the front wall..and the 2" thick on the side and back walls..

Really? would it just be better to go 2" everywhere then? From what I've read you want the screen wall as dead as possible?

Quote:

Prof. wrote:

There seems to be two schools of thought on this..Some say chunks are best , and others say flat panels across the corners...
I have 6" thick panels across the corners and they do a good job..

I would suggest that what Jason has done would be a very effective trap..
From what I understand, he's used 4" thick Ultratel with a 2" thick Quietel panel to make up a 6" corner trap..

Did you originally plan to do the chunks? I thought I remembered you telling someone how to cut them up, maybe I just assumed that's what you had.

I don't really mind which option because it's behind the screen wall anyway. Just want the best option available

Quote:

Prof. wrote:

Also, your sketchup isn't showing any rear corner traps..Is this just an oversight?

I'm not sure what to do for the rear corners. Here's a pic of my dilemma

Rear treatments

The door on the side of the room doesn't leave much room for a corner trap, from the edge of the door to the rear wall is only around 200mm.

Would it be worth doing a baby superchunk in there?

I have room to play inside my soffits if that will help the room? I was just going to fill with insulation, but I can leave an air gap behind it if that will help it act as an absorber?

Cheers,
Simon

**bpape** · **07-26-09, 08:25 PM**

The front wall can be 1" or 2". I prefer 2" to help deeper with SBIR issues as well as surround reflections.

On the side walls, do the first 5' or so floor to ceiling. 1" is OK if space is at a premium.

On the rear wall, use something thicker and do full wall coverage - but use an FSK facing on it to keep the surround lively while still being able to help with nulls off the rear wall in the bass range.

Bryan

**Prof.** · **07-26-09, 08:25 PM**

Quote:

raZorTT wrote:

Really? would it just be better to go 2" everywhere then? From what I've read you want the screen wall as dead as possible?

Well if you were going to use two different thicknesses, then that's the way I would do it..But using 2" thick all round would be better..

Quote:

Did you originally plan to do the chunks? I thought I remembered you telling someone how to cut them up, maybe I just assumed that's what you had.

I was originally going to use chunks, but then I heard about the effectiveness of spaced flat corner panels for traps..
So I decided to try the panels first ( much less work..

) and see how they performed..I could always do the chunks later if need be..
I was so impressed with the bass performance that I decided to leave it as they were.

Quote:

I'm not sure what to do for the rear corners. Here's a pic of my dilemma

Rear treatments

The door on the side of the room doesn't leave much room for a corner trap, from the edge of the door to the rear wall is only around 200mm.

Would it be worth doing a baby superchunk in there?

That's a nasty little corner..
It doesn't look to be much corner wall area with the door open..but with the door closed, you then have a large empty corner again..
There's probably not much you can do about it...Possibly placing a vertical panel on the side wall above your existing insulation..and a panel on the door, might help a bit..

Quote:

I have room to play inside my soffits if that will help the room? I was just going to fill with insulation, but I can leave an air gap behind it if that will help it act as an absorber?

I would still fill any soffits with insulation..

**Prof.** · **07-26-09, 10:19 PM**

Quote:

raZorTT wrote:

Based on what I could find going through the various threads, Bradfords Ultratel is the most suitable insulation for treatments on the sidewall and rear walls. The rear walls (slightly different colour) should have an FSK or equivalent facing to keep the rear a little lively (thanks bpape!). I had planned for the sides and rear to be 25mm (1") thick.

When I was making my rear window plug, I asked Bradfords about FSK and they informed me that they don't have that product..
The only facing they have with Supertel or Ultratel is a BPF facing (Black Paper Face) and it's a lot more expensive than the plain fibreglass..

I bought it and used it in the window plug, but have always wondered whether it was as effective as the FSK..
It's only a very thin membrane on the face of the fibreglass..

Just recently I've been doing some experimenting, placing different material in front of the window plug, to see if there is any improvement in reflecting the highs..

The different paper based materials I tried didn't seem to make much difference, so in desperation I whacked up a piece of 3mm. MDF in front!!

Wow!!.. did that change things dramatically!!..
Surround sounds were much more detailed and seemed to project more coherently to locations in the room, where you would expect to hear them in respect of the action on the screen..
Interestingly enough..bass extension seemed to be even better, but I don't know if that was just my imagination..

I'm doing further tests at the moment using Mylar as the high frequency reflector..
I'll let you know the outcome of that..

**raZorTT** · **07-26-09, 11:13 PM**

Quote:

bpape wrote:

The front wall can be 1" or 2". I prefer 2" to help deeper with SBIR issues as well as surround reflections.

On the side walls, do the first 5' or so floor to ceiling. 1" is OK if space is at a premium.

On the rear wall, use something thicker and do full wall coverage - but use an FSK facing on it to keep the surround lively while still being able to help with nulls off the rear wall in the bass range.

Bryan

Thanks Bryan!

Space isn't a huge issue so i'll look to go 2" everywhere and i'll update my model so the first part of the side walls and the rear wall are floor to ceiling.

Do you have any preference on the superchunk versus hanging for bass traps?

Cheers,
Simon

**raZorTT** · **07-26-09, 11:22 PM**

Quote:

Prof. wrote:

Well if you were going to use two different thicknesses, then that's the way I would do it..But using 2" thick all round would be better..

2" it is

Quote:

Prof. wrote:

I was originally going to use chunks, but then I heard about the effectiveness of spaced flat corner panels for traps..
So I decided to try the panels first ( much less work..

) and see how they performed..I could always do the chunks later if need be..
I was so impressed with the bass performance that I decided to leave it as they were.

The only thing is the bottom of my soffit is about 2.7m off the ground and the sheets are only 2.4m long :-\

Quote:

Prof. wrote:

That's a nasty little corner..
It doesn't look to be much corner wall area with the door open..but with the door closed, you then have a large empty corner again..
There's probably not much you can do about it...Possibly placing a vertical panel on the side wall above your existing insulation..and a panel on the door, might help a bit..

Yeah nasty is right! do you think a chunk with a 300mm face (1/2 normal) would be worth it?

I'll definitely put some panels on the door. Actually, have been thinking maybe I need to switch it from opening out to opening in so the panels will be a bit more seamless.

Quote:

Prof. wrote:

I would still fill any soffits with insulation..

Would you pack them completely? Or leave a bit of a gap at the top?

Cheers,
Simon

**raZorTT** · **07-26-09, 11:28 PM**

Quote:

Prof. wrote:

When I was making my rear window plug, I asked Bradfords about FSK and they informed me that they don't have that product..
The only facing they have with Supertel or Ultratel is a BPF facing (Black Paper Face) and it's a lot more expensive than the plain fibreglass..

I bought it and used it in the window plug, but have always wondered whether it was as effective as the FSK..
It's only a very thin membrane on the face of the fibreglass..

Just recently I've been doing some experimenting, placing different material in front of the window plug, to see if there is any improvement in reflecting the highs..

The different paper based materials I tried didn't seem to make much difference, so in desperation I whacked up a piece of 3mm. MDF in front!!

Wow!!.. did that change things dramatically!!..
Surround sounds were much more detailed and seemed to project more coherently to locations in the room, where you would expect to hear them in respect of the action on the screen..
Interestingly enough..bass extension seemed to be even better, but I don't know if that was just my imagination..

I'm doing further tests at the moment using Mylar as the high frequency reflector..
I'll let you know the outcome of that..

Wow that sounds promising! Definitely keep us posted! Sounds like I should look at buying some ultratel in bulk then for the rear wall building in either thin mdf or the mylar in the panels!

Have you tried some 6mm gyprock? wondering if that would work like the MDF?

Thanks Prof!

Simon

**raZorTT** · **07-27-09, 03:23 AM**

Ok I did up the changes in sketchup.

Treatments

All the treatments are 2" thick now and the first 1.5m (5ft) and rear wall are from floor to ceiling.

Do you think I should stick the insulation in the columns too? seeing as they're only covered with GOM. Probably wouldn't hurt.

Prof. for your bass traps did you cut a 1200mm sheet into two and sandwich them together? so you have a 600mm face?

Cheers,
Simon

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