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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Jamie Triplett on March 13, 2018, 10:11:03 am

Title: Help on installing sound treatments
Post by: Jamie Triplett on March 13, 2018, 10:11:03 am
I have a room that is very echo-y when people use it for singing, speaking, and other sanctuary-type activities.  We are installing a new sound system in the room, and I want to put up some sound treatments in the room as well so we can reduce the echo.  There's lots of wood in the room and sound just bounces around. 

Here are two pictures of the space.  We are looking for something that could go on the walls/ ceiling and reduce the forward to back echo, maybe reduce the "brightness" a bit.  Does anyone here have a good idea of placement of treatments? Type? Affordability?

Thanks in advance.

Front:
(http://i.imgur.com/xjotyVO.jpg) (https://imgur.com/xjotyVO)

Rear
(http://i.imgur.com/JrEQlMD.jpg) (https://imgur.com/JrEQlMD)
Title: Re: Help on installing sound treatments
Post by: Jean-Pierre Coetzee on March 13, 2018, 10:30:51 am
Despite wondering why a room that small even needs a sound system here it goes.

2-4" Fiberglass batting (80Kgm3) wrapped in a fire resistant cloth mounted about 2" from the wall. You will be sorted with absorption down to about 250Hz and it should be reasonably cheap. Where, well that will depend entirely on where the speakers are going to be placed.

Will this substantially help? I don't think so, I think the majority of your reflections are coming from the floor, that wood ceiling probably isn't reflecting much sound in the first place. A think carpet or just filling the room with people will probably help your situation a lot more than spending ton's of money on acoustic treatment for a room that probably seats like 25-50 people.

There is a few designs online for diffusion panels if you are slightly competent at woodworking that is also a solution if you just want to get rid of slap but not kill the reverb in the room.
Title: Re: Help on installing sound treatments
Post by: Robert Healey on March 16, 2018, 05:27:49 pm
Will this substantially help? I don't think so, I think the majority of your reflections are coming from the floor, that wood ceiling probably isn't reflecting much sound in the first place. A think carpet or just filling the room with people will probably help your situation a lot more than spending ton's of money on acoustic treatment for a room that probably seats like 25-50 people.

I think this is poor advice. The ceiling is the perfect place for treatment in this room. Given the shape of the room it's pretty much the only place treatment can go. Just because you aren't getting useful reflections from the ceiling (directing sound to the audience) doesn't mean it isn't reflecting sound and creating reverberation. In a room with zero sound absorption, every surface is an issue.

Carpet has poor sound absorption characteristics - modern commercial carpet has a lot of high frequency absorption above the vocal range but very little in the frequency range that actually counts. It likely won't be effective, and will be even less so with people in the room that cover it up.

To the OP - as an acoustical consultant, I couldn't tell you exactly how much treatment and the placement that you need without an actual analysis of your room - which would involve plans, dimensions, etc. What is your location? Maybe you could find a local consultant to assist.
Title: Re: Help on installing sound treatments
Post by: Don T. Williams on March 17, 2018, 01:25:39 pm
I'm not certain where you are located, but in the USA, Owens Corning offers their 703 series of "hard" fiberglass panels in 2' x 4' sizes in 1", 2", and 4" thickness that are UPS shippable.  These are much easier to handle and cover in flame proof fabric that batt type fiberglass .  Owens Corning also offers pre covered finished products, but at significantly higher cost that the "roll your own" version.  This product is also available in large sheets (4 X 8) but your space doesn't look to need these.
Title: Re: Help on installing sound treatments
Post by: Alex Donkle on March 24, 2018, 06:12:37 pm
Treating the ceiling is your best bet, as already mentioned carpet doesn't actually do much for most frequencies. One option is just covering the entire ceiling in fabric-wrapped acoustic panels, but your better bet is finding a local acoustic consultant who can do a quick RT60 test of the room, and recommend an exact sq. footage of treatment (most likely, their total fee will be less than what you'll save by just treating the entire ceiling).

Buying Owens Corning fiberglass panels and wrapping it yourself was mentioned, which is possible, however I've seen this attempted a few times and it rarely looks good. Buying pre-wrapped fabric panels from an acoustic company (e.g. Kinetics, Decoustics, MBI, Armstrong, etc.) is nearly always a better way to go so you get a decent looking end product.