Acoustical solution needed...

**Sonnie** · **08-17-06, 09:40 PM**

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.

**Fincave** · **08-18-06, 02:39 AM**

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!

**Wayne A. Pflughaupt** · **08-18-06, 11:21 AM**

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!

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

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

**Sonnie** · **08-18-06, 12:03 PM**

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.

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.

**JCD** · **08-18-06, 07:46 PM**

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.

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

**Sonnie** · **08-19-06, 12:21 AM**

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

**Alan Brown** · **08-20-06, 12:03 PM**

Quote:

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?

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?

**Sonnie** · **08-20-06, 01:14 PM**

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

**Josuah** · **08-20-06, 01:28 PM**

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.

**Sonnie** · **08-20-06, 10:02 PM**

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

**Sir Terrence** · **08-21-06, 10:58 AM**

Quote:

Sonnie wrote:

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.

**Wayne A. Pflughaupt** · **08-21-06, 01:31 PM**

Quote:

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

**Sonnie** · **08-21-06, 03:29 PM**

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.

**bpape** · **09-14-06, 02:14 PM**

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

**chasw98** · **09-21-06, 06:10 PM**

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

**Sonnie** · **09-22-06, 08:41 AM**

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.

**chasw98** · **09-22-06, 09:02 AM**

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

**Sonnie** · **09-25-06, 12:54 AM**

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.

**bpape** · **09-25-06, 04:44 AM**

Well, it may help a little bit - heck, 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

**Ethan Winer** · **09-26-06, 03:59 PM**

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

**Sonnie** · **09-27-06, 02:23 AM**

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.

**Ayreonaut** · **09-27-06, 01:21 PM**

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 prima

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