# Acoustical solution needed...



## Sonnie (Apr 11, 2006)

Below are a few shots of our fellowship hall that we have recently refinished. Unfortunately tile was opted for instead of going back with carpet. We had no echo problems previously with carpet.

We have some pretty picky ladies that are going to be very difficult to please when it comes to taming the serious echo we have created. It's near impossible to carry on a conversation in the room.

We have suggested to the ladies that we build and locate large 3' X 8' or 4' X 8' panels all around the room directly above the chair railing. We plan on using 2" X 2" frames with regular fiberglass insulation and cover with one of the 54 samples of GOM material we have to choose from. Of course they were none to crazy about having the big panels placed around the room... not even in every other open space.

What the ladies are saying that they would accept is for us to build panels to go around the bottom of three sides... all sides except the kitchen area. These would be approximately 30" x 8' panels below the chair railing and between the receptacles. Notice the red block in the last picture.

We have no idea whether this will do the job or not. Obviously we don't want to purchase all the materials, build the panels and then they not be sufficient to work.

We are looking for ideas, suggestions, alternatives. They must be inexpensive, thus our suggestion of building them ourselves. No way we will spend the small fortune it would require to buy panels.


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## Fincave (Apr 20, 2006)

I would have a look at http://www.ecophon-us.com/default____5318.aspx they have quite a lot of info on their pages as well as suggestions etc for different situations ie restaurants, schools, cinemas, etc. Am not sure about the pricing in the US but in Finland they are not too pricey. Hope this helps!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Sonnie,

This has nothing to do with home theater, so I’m moving it to the Off Top... Oh wait, you’re *that* Sonnie! Sorry! Sorry about that! :laugh: 

Couldn’t pass up a chance to rib ya a little. :neener: 

On to the topic at hand - this is really pretty simple. Calculate how many square feet of carpet was removed from the floor. That’s how many square feet of treatment that needs to be applied elsewhere if you want things to get back to the way they were before. If you want to reduce the current reverb problem by half, then treatment coverage equaling half the amount of lost carpet is needed. And so on. 

Bottom line, I can’t see how treating the area below the chair rail will make a dent in the problem. It’s a waste of money to even try. Just imagine if that area was covered with carpet. Now imagine that carpet removed from the wall and laid down on the floor. What would it cover, about two tile-widths around the outer parameter of the room? It’s nothing, a drop in the bucket compared to what was lost. And you’re talking about panels, which won’t even cover as much area as a solid length of carpet would.

You do have more of a chance by treating the upper area above the chair rail, but pretty much fully covering the walls with some kind of soft covering is about the only way you’ll ever restore things back to the way they were. By “soft covering” I mean something thick enough to have a nap – something between wall paper and carpet. That’s what you need in order to have any absorption. I have some stuff in mind, but it’s hard to describe. I’ll show you some next week when you’re here for the meet.

I’ll admit I’m pretty jaded when it comes to this kind of stuff, but if the ladies prefer their choice of aesthetics over the annoying echo, I say let them have it. If enough church members get their ire up, maybe they’ll be overridden. Save your money for when that happens.

Regards,
Wayne


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## Sonnie (Apr 11, 2006)

lol... well this is kind of a theater type room.... see the two speakers in the top corners of the rear wall? heehee... and it's about acoustics. :neener: 

I wonder if covering that entire back wall would do anything... somewhat trap the reflections, so to speak. We hung curtains up around that kitchen area (there are hooks on the inside edge that you can't see) and it helped quite a bit... it didn't take all the echo out, but you could at least carry on a conversation better. That's a pretty small area where the curtains were hanging that made a noticeable difference. I guess that's why we were thinking the area below the chair rail might help.


Thanks for that link Fincave... I looked at it briefly and will check it out more. I'll probably give it to a few others and have them read up on it too.


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## JCD (Apr 20, 2006)

One of the topics I can answer.. not. Basics for a regular home theater -- adequate but not confident -- a huge hall like that? Nope, no, uh uh, zip.:scratch: 

If you end up not finding the answer you'd like, there is an accoustics forum hosted by the guru himself, Ethan Winer. A true believer with all that (good and/or bad) entails, but I'd seek out his opinion if you can't find an adequete answer here.

JCD


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## Sonnie (Apr 11, 2006)

Thanks Jacen... never knew it existed. Ethan knows his stuff for sure... and he's probably got plenty of folks there to make suggestions.


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## Alan Brown (Jun 7, 2006)

> It's near impossible to carry on a conversation in the room.


.....and the point of a "fellowship hall" is to sit silently together and stare at the undisturbed, newly painted walls?:yikes: 

Get 2" rigid fiberglass board from an HVAC supplies wholesaler. It comes in several sizes and at least two densities. The higher density is preferred. Spray 3M adhesive on the edges and wrap your acoustically transparent Guilford of Main fabric around it. Place the panels above the chair rail in sufficient numbers to tame the reflections adequately. Allow the ladies to pick out the color. Doesn't that sound easy?:T


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## Sonnie (Apr 11, 2006)

You hit the nail on the head... it "sounds" easy!


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## Josuah (Apr 26, 2006)

I'd say go for the ceiling. Most people won't notice white panels placed on the ceiling as long as it doesn't block out the light, and it'll do a lot to reduce the echo because you've got almost the same amount of surface area as the floor. Done fancy and it will just look like a normal part of the ceiling.


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## Sonnie (Apr 11, 2006)

That's a thought there Josuah... that might could work without much resistance from the ladies.


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## Sir Terrence (Jun 8, 2006)

Sonnie said:


> That's a thought there Josuah... that might could work without much resistance from the ladies.


I am not sure dealing with just your ceiling only will do the trick. Remember that most of the vocal activity happens closer to the floor, and with air absorption and the distance from the floor to the ceiling, I am not sure the ceiling would be contributing much to your echo problem. I have to agree with Wayne on this one, you must treat the area above the rail to even make a dent in this kind of room with long parallel bare walls and bare floor. Even if you do treat the areas above the railing, you are going to have a significantly audible floor bounce if you decide to use musical instruments in this room. 

I am really an acoustical nazi. When my church updated its smaller sactuary/concert room's sound system, I insisted that we do some extensive acoustical treatment to tame some nasty echo's that were audible in certain parts of the room, and the dryness in other areas( hotspotting) I met with tremendous resistance from some of the women of the church, the very folks that complained about the acoustical problem in the first place. My answer to them was "either you have a very pretty acoustically untouched room where you cannot here a thing in some spots, and too much in other, or you allow me to take both the acoustics and aestetics(sp?) into consideration and correct the problem". I also stated to them that it would be of no use upgrading the sound system if you didn't correct the hotspotting thoughout the room, its a waste of money you would be stuck with the same problem you were trying to correct. I won out rather quickly. 

It has to take some folks to get so annoyed with a problem, that there own personal aestethic desires take a back seat. I cannot see how you can improve the acoustics without treating the upper 2/3 of that room.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I also stated to them that it would be of no use upgrading the sound system if you didn't correct the hotspotting thoughout the room, its a waste of money you would be stuck with the same problem you were trying to correct.


Absolutely! If the acoustics are bad, no amount of money spent on a sound system will make up the difference. 

Regards,
Wayne


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## Sonnie (Apr 11, 2006)

There is no sound system or instruments other than a couple of speakers that are not hooked up. Those are there only for a P.A. system, but we really don't need it. You can hear fine from one end to the other, you just can't understand what anyone is saying.

If we can get the voice echo tamed, we'll be fine. Hopefully the ladies can pick out a GOM fabric that they can live with using panels above the railing.


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## bpape (Sep 14, 2006)

I'd agree that you need to get some control up higher in the room. Maybe something like a 4'x4' diamond shape between each window? That might pass the ladies' test?

Also, you should likely consider something large on the flat wall above the kitchen area. Maybe something made to match the general shape of the vault. That long dimension is causing a lot of issues as those are the longest echos from a time perspective.

Ceiling might help some but realistically, hanging baffles (probably poor acceptance factor) work very well in areas like that - but not exclusively - you still need the on the wall solution(s).

Bryan


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## chasw98 (Apr 20, 2006)

Sonnie:
Have you worked out the numbers for this room? If you were to set up a spreadsheet with the noise coefficients of what was in the room before and what is in the room now, you would be able to predict the effects of hard earned church donations being spent on magical acoustics. By taking the surface area of all 6 sides and applying their noise coefficient to them based on the materials used in the room, both before and after, you would know what you needed to make up the difference from losing the carpet. Wayne pointed this out in his earlier post. With good measurements and some calculations you can predict the RT60 of the room and what it will take to carry on an intelligible conversation there.

Chuck


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## Sonnie (Apr 11, 2006)

We haven't done any testing or measuring... I wouldn't even know where to begin. It's like the subject of fixing it has gotten silent as to suggest, let's just leave it alone. 

I'll probably have to re-open the issue with the elders.... they were some of the ones complaining to get it fixed.


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## chasw98 (Apr 20, 2006)

Sonnie:
Basic measuring consists of measuring with a tape measure the area of all the flat surfaces in the room and making a note of what material is in that area. i.e. ceiling, north wall, south wall, etc. Then you go home and apply the standard noise coefficients to each surface. Then you have an idea of where you stand with the room. With those measurements any good acoustician can make a recommendation as to treatment to bring the RT60 down to a level that won't interfere with the spoken word. BTW, the 2 speakers on the opposite ends of the wall are definitely not helping your problem. The speakers should have been mounted in the center angling outwards so that you have a single point source of amplified sound. Right now you have 2 sources that are bouncing all over the room and interfering with each other. Just my .02.

Chuck


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## Sonnie (Apr 11, 2006)

Those speakers will most likely never get hooked up. We really have no use for them in that room... they are just there because they were there before, but we've never used them. 

I can measure everything... every wall and the ceiling is sheetrock... the floor is ceramic tile.

I mentioned the diamond panels to one of the ladies today and she said they really wanted to try installing the panels in originally suggested area below the chair railing. I told them that it may not do any good. I don't know... they can be stubborn at times.


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## bpape (Sep 14, 2006)

Well, it may help a little bit - ****, in that room pretty much anything will help a little bit. Too bad there isn't a practical way to temporarily hang some things up so they can hear the difference. It would be so obvious even to the layman(woman).

Bryan


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## Ethan Winer (Jul 21, 2006)

Sonnie,

I agree with the others that a narrow strip around the bottom of the side walls will not do much. However, you could make a very large improvement by putting the bulk of the absorption on the ceiling. I've treated quite a few rooms just like yours, where putting visible "things" on the walls had to be avoided or kept to a minimum. Doing only the ceiling helped a lot. The tip off is your comment, "We had no echo problems previously with carpet." That tells me the primary echo is between the floor and ceiling. So treating one or the other will give similar results. You'd still do well to put some absorption on a few areas of wall too, but treating the ceiling would at least get you "back" to what you had with carpet.

--Ethan


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## Sonnie (Apr 11, 2006)

It would definitely be easier to hide in the ceiling. I failed to mention another significant change... we removed the lowered acoustical tile ceiling and went back to the original ceiling which is 8' taller. It would seem the vaulted ceiling is contributing a good bit to the echo.


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## Ayreonaut (Apr 26, 2006)

At a Church I visit in Lexington, NC they have a large hall and it echoes terribly. For years they did nothing, but finally they put panels on the walls between the windows all the way down both sides and across the back. It really didn't help much. The primary echo problem there seems to be between the floor and ceiling.


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## Ethan Winer (Jul 21, 2006)

> we removed the lowered acoustical tile ceiling and went back to the original ceiling which is 8' taller. It would seem the vaulted ceiling is contributing a good bit to the echo.<

Exactly.

> It really didn't help much. The primary echo problem there seems to be between the floor and ceiling. <

That's why it pays to deal with professionals when dealing with "big" jobs like that. A competent pro could have saved a lot of money, effort, and heartache.

--Ethan


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## Sonnie (Apr 11, 2006)

Small town congregations don't typically hire pro's to work on the church building. Us ******** and hillbilly's don't think about things like this. :sarcastic: We hillbilly's just do it. I'm not even sure we have any professionals anywhere within driving range of us anyway.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> Small town congregations don't typically hire pro's to work on the church building. Us ******** and hillbilly's don't think about things like this. :sarcastic: We hillbilly's just do it.


 Yikes! It scares me to think what I’m going to find when I check out your church’s sound system when I come to visit! Speakers hanging from rope? Stacks of power amps plugged into cheap power strips? Telephone wire as speaker cable? :mooooh: 

Regards,
Wayne


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## Sonnie (Apr 11, 2006)

Yeah... hopefully you'll be well received at the door... if we have folks that appear like they might be a problem (you know appearance is everything in worship), we usually stick them under the hanging speaker... the one that's got the really old phone wire holding it up. It's fell several times during loud preaching. Don't fret though... we'll take ya right on out back and give ya a respectable burial. You being the audio guy you are, we'll toss a few of our old cables in the coffin with ya. :devil:


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## dynamowhum (Oct 3, 2006)

Sonnie we have a fellowship hall with the very same problem. Please post when you have a resolution to your problem as we are also looking for a solution. Like you we are a small congregation so we can't afford professional talent. Cheers.


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## Sonnie (Apr 11, 2006)

I'm beginning to wonder if we'll ever find the solution that will satisfy the ladies and be cost effective.


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## dynamowhum (Oct 3, 2006)

Sonnie after 27 years of marriage I have come to the conclusion that you can not please a woman.


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## Sonnie (Apr 11, 2006)

lol... yup... 22 for me... Amen!


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## JCD (Apr 20, 2006)

Well, I guess I'm purty smart then, it only took me 5yrs.. :surrender: 

JCD


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## dynamowhum (Oct 3, 2006)

You sir are a veriable genius with true vision.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Veritable maybe? 

Regards,
Wayne


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## dynamowhum (Oct 3, 2006)

Yeah everyone is a critic:rolleyesno: :surrender: :laugh: Never made any claims to genius myself remember it took me 25 years to figure it out about women.


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## JCD (Apr 20, 2006)

5 years of marriage, but 39 years of having a mom and two sisters and 28 female cousins.. it took a while too, but eventually, you learn "Men=Wrong, Woman=Right".. :dumbcrazy: 

JCD


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## Guest (Oct 28, 2006)

Just to reinforce what Ethan Said to some extent.

you CAN make a significant difference using appropriately located wall mounted absorbers, but they'd be muonted much higher up than you were discussing previously... but the most effective and invisible solutions would be ceiling mounted absorption panels... or a False ceiling of acoustic tiling... 

note that they should not be mounted hard against the ceiling surface, but hung a little below it... approximately 50% of the flat ceiling space surface area, , in a chequer board pattern would be a good place to start.... 

Panels can also be hung arranged in the vertical orientation, to act as baffles to control the high level wall to wall flutter echoes... imagine it like a cloud of absorption... taming both the simple floor to ceiling reflections, and some of the more complex floor-wall-ceiling interactions.... 

this could be done and still maintain the nice open, high ceiling feel of the room, but the simplest answer, and sometimes the most cost effective is a straight forward , flat suspended false ceiling, like you see in office blocks, ,made using acoustic ceiling tiles, some of which are specifically designed and voiced to increase vocal intelligibility, and reduce cross contamination between office spaces.. , (Ecophon is one european ceiling tile name that might be available stateside.. ) 

If i were looking at the room with a musical eye on it, I'd mix diffusion devices with absorption.... 


other small but important touches can also make a useful difference... things like using plush deep soft furnished chairs rather than hard surface plastic or wooden hard chairs... seems too simple, but it can make a difference... 

throwing the numbers in to one of the room evaluation packages might well give you some idea of how bad it is, but it won't necessarily give you the right answer in terms of choosing and placing acoustic treatment....  better to get a professional out, even if for only one day.... 
I know of a few who work in the US, but really I have no idea of any of them are geographically useful to you.... 
I would suggest you contact RPG Inc 

http://www.rpginc.com/

I use their products here in Europe (although from their European subsidiary) and IMHO, they're without doubt the best and most comprehensive supplier of acoustic solutions, and they're led by one of the worlds foremost acousticians, with proper research facilities and scientific back up.

Ethan Winer's company, "Real Traps", also supply some useful products, both in the US and over here.... and at pretty reasonable prices... But RPG are the real experts when it comes to complex solutions.... (sorry Ethan, but it's an unbiased reality, even Auralex are newbies compared to the guys at RPG. ) 

Ethan is however, very much a champion of bringing acoustic ideas to the ordinary joe... in as plain and easily digestible a manner as possible... some acoustics experts criticise him for perhaps simplifying too far now and again, but his intention has always been honourable, to educated the masses and make acoustics at least partially understandable for the average joe on the street.... More power to his keyboard i Say !




.... Can't really help on site, as i'm UK based.... but for the record, I build recording studios for a living... both Live spaces and control room spaces.. and occasionally do a bit of acoustic consultancy for Schools, Churches and Theatres etc. 



Regards

Max The Mac

AKA

Max Hodges
Consulting Engineer
Maxtech Audio Services
Oxford
UK.


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## Sonnie (Apr 11, 2006)

Hi Max and thanks for chiming in. I'm going to mention a few things to our ladies about doing something on the ceiling and high up on the walls. I think they would definitely go for that. As far as installing a complete acoustical ceiling, we tore the one we had out so we could have the vaulted ceiling back to original height.


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## Guest (Oct 28, 2006)

I realise you ripped out the old ceiling Sonnie, you did say so earlier.... I thought i'd just subtly hint that that was probably a mistake as far as your immediate problem goes  without actually rubbing anyone's nose in it..... :sneeky:


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## Guest (Oct 28, 2006)

Have you look at building a Helmholtz's resonator to modify the resonant frequency of the room

they can be painted and made to look quite stylish

also maybe look at http://www.odeon.dk/about.htm
and
http://scitation.aip.org/getpdf/ser...02000002000061000001&idtype=cvips&prog=normal

I also have a colleague who is looking into acoustic room modeling at present i'll ask her some ins and outs

id suggest for standing waves

staggered absorption along the walls

for reflection find the end that will have most of the focus and diffuse the other end with reflective foam and also the Helmholtz

and maybe some corner diffusion as well

rubber shops sometimes sell foam cheap that you can paint and cut to size - I recently bought some for $10/foot


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## Ethan Winer (Jul 21, 2006)

Max,

> RPG are the real experts when it comes to complex solutions.... (sorry Ethan, but it's an unbiased reality, even Auralex are newbies compared to the guys at RPG. ) <

No offense taken. Dr. D'Antonio is very much "da man" when it comes to acoustics. Then again, you don't really need Jonas Salk to give you an annual physical. What matters with acoustic treatment is the quality of the products and the quality of the advice you get. If you call RPG to ask what acoustic products you need and where to put them, I promise you Dr. D'Antonio will _not_ be the guy who takes your phone call. When you call RealTraps you get me in person.

> some acoustics experts criticise him for perhaps simplifying too far now and again, but his intention has always been honourable <

That old saw has been totally discredited. As it turns out, I was right all along. :raped: Email me through my company's site if you want more info on that.

--Ethan


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## basementjack (Sep 18, 2006)

Hey if you are looking at Guilford fabric, be aware that they have MANY MANY patterns and styles to choose from 54 choices sounds like you've been looking at the FR701 which is UGLY UGLY UGLY.

I phoned GOM and got the number of my local rep - she sent me a few dozen sample pages - each page has about 10 small fabric samples, and often one larger one. From that I quickly narrowed down what I wanted and ordered 'memo' samples from the GOM website - (memo's are appox 8x10)

One fabric you might look at is Anchorage - its a plain fabric (no pattern) but the look has a higher quality about it - and it's available in I think about 50 colors or so. Including many shades of brown that would fit right in with your room.

One possibility I didn't see mentioned when skimming this thread - would be to build a 'false wall' made entirely of fabric - right above the kitchen - IE - frame out your 2 inches or so, put up your rigid fiberglass, and then cover every inch of wall with fabric - at that point - the fabric becomes the wall, and is barely noticeable - and hardly objectionable, as it gets past the whole 'panel' issue.


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## Sonnie (Apr 11, 2006)

We have 50+ samples to look at.... I'd say they GOM has 200-300 or more. We got samples running out our ears and several of them are very nice. 

We are looking at possibly doing something on that wall above the kitchen and high up on all the walls... just not sure yet. The ladies are having a hard time making up their mind what they want.


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## Guest (Nov 20, 2006)

I have found that the best place to start is with trapping troublesome low frequency modes. This is best achieved by using Linear-X which will quickly identify the troublesome frequencies, if that is not available try the Real-traps test tones. 

The 3rd and 5th harmonics of the identified modes (booms) will cause continue to cause problems in the frequency range 300 - 4.5kHz if not treated, however much fiberglass you add!

Treat the bass with tunable traps to accurately tame those resonances, then by using Aoustic-X, if anyone still has access to that fabulous product, to calculate the treatment required for a room of that size,. When treating a large area a variety of surfaces are required if you are to keep a flat responcse, ie you do not want to suck all the life out of a room by only having soft absorption. 

Ref - Membrane Absorbers in Alton Everests - Master Book of Acoustics 4th edition pp213-4. Also you must factor the absorption of air into rooms of more than 1000 cu Ft. p203 als0 Everest. Then use a Sabine spreadsheet to calculate the existing RT before "treatment" is condsidered.

Good accurate trapping will improve things remarkably if carefully and accurately done, post operative shock syndrome etc! 

Another alternative to soft surfaces and membranes is polycylindricals which can look really good, by increasing the surface area relative to the room volume, good for areas that suffer from slapback or pinging.


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## Seb (Apr 22, 2006)

I think I would keep it simple. If I have understood correctly, previously the room had absorption on the floor and ceiling and was satisfactory. I think you need to put back the carpet and/or ceiling absorption.
Ecophon is a terrific ceiling product, can be direct-fixed, but costs $$$.
I have concerns about DIY acoustic panels on ceilings - White fabric dos not have as much light reflectance as a white painted surface so the room may get a bit darker visually. also, fabric is likely to stain and sag over time.
What I have done in some large houses is to fix acoustic panels to the ceiling in certain areas - e.g. running between light fittings - made in this way: 50mm battens fixed to the to the ceiling, absorption material taped in place between the battens, white polyester or acoustic fabric over the front of the batts, then fix perforated plywood or perf plasterboard over the front (fixed to the battens). Paint it all white before installation (don't fill the holes...) & works very well. 25% open area perf is best but even as low as 10% open area with 50mm thick batts will still have more absorption than the carpet that was there b4.
If that is not enough then I would suggest run heavy drapes over the walls between the windows. Only really needs to cover the plane of ppl speaking, i.e. between about 800mm and 2000mm. Personally I think it would look fine above the rail.


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## Danny (May 3, 2006)

As all of the walls are solid you are having a lot of reflections between them. I agree with Wayne in saying that you will need roughly the same amount of padding as you had carpeted previously. Try to get materials that have a lot of mass to absorb the sound, have heard that fibreglass is really good for absorbing sound. I'm glad I don't have to install it though i hate working with fibreglass


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## drf (Oct 22, 2006)

Just wondering how have you got along with this problem? are there any advances yet?


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## Sonnie (Apr 11, 2006)

Nothing... something tells me we'll never do anything. It's really out of my hands. I've offered to help, but no one is making a final decision and I'm not in a position to be able to make that decision. I've pretty much let it be and if someone asked me about it... I defer to the Elders.


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## SteveCallas (Apr 29, 2006)

Just came upon this. I'm no acoustical expert, but I do lift weights......and one of the things I notice in a lot of gyms (which have most of their walls covered by mirrors, have painted drywall ceilings, and plenty of noises being created from weights clanging and cardio machines blazing) is acoustic panels suspended from the ceiling by wire. The panels are maybe 2'x8' and spaced at even intervals. Seems to work pretty well.


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## Sonnie (Apr 11, 2006)

That has actually been discussed, but it seems it's pretty much left up to what the ladies want and they can't all agree on what it is they want. We've suggested every possible scenario. I guess one good thing about it is no one is complaining about the echo anymore... :huh:


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