The Conference Room Is Too Loud

August 19, 2008 11:30 AM

In my office there is a small conference room, 81"x96", maybe 18' ceiling. The walls are sheetrock. The echo is extremely irritating. In order to quiet the room a bit I want to mount squares of corkboard, 12"x12"x1/4". I will use 12 to 20 of these squares on one of the 81" walls. Will this be reasonably effective in lessening the echo?

A 4-pack of the 12"x12" corkboard squares is only about $12, and I can't find any special sound-deadening material thats anywhere close to that cheap.

What is the best method for mounting them to the wall? Double-sided tape seems like the easiest way to go, and we're not concerned whatsoever with keeping the wall behind it looking pretty. It can be repainted someday if necessary.

posted by ben242 to grab bag (15 comments total)

It's possible to buy advesive-backed cork by the roll - here for example. I've mounted cork wall tiles with a special adhesive in the past; that worked pretty well, but was a bit messy to apply. I can't say I've tried double-sided tape, although I would think that the sort used for carpet edging would do the trick nicely.

Cork will certainly help reduce echoes, as will curtains, fabrics, carpets and soft furnishings.
posted by le morte de bea arthur at 11:42 AM on August 19, 2008

Look into Homasote. These come in 4x8 sheets and are typically grey. You can cover them with fabric or paint them and they make a great pin-up board. It is typically about an inch thick. I got some locally at a place called Mr. Plywood. You might need to try the smaller mom and pop stores. Though I think if you do searches online you can find a local supplier -- look at homasote.com.
posted by amanda at 11:43 AM on August 19, 2008

Is your room really 6x8 with 18' foot ceilings? Sounds like an elevator shaft! Since the span is so do-able, I'd recommend hanging fabric in a kind of swoop from the ceiling. You could use cabling or some kind of rod and then hang three "swoops" of fabric at a height which would make the room feel more cozy and definitely reduce the echo. Get a white, sturdy cotton and if you have lights above it then it will create a nice, even and soft lighting effect.
posted by amanda at 11:46 AM on August 19, 2008

Unfortunately, it will likely not do too much. Reducing reverb and echo on the cheap while still looking good is extremely difficult.

In a room with 18' ceilings, you are going to need a lot more of the space covered for it to be very effective, and (as I understand it), cork doesn't do such a great job of absorbing sound.

I don't know if the conference room is used for public meetings, and how nice it needs to look, but squares of thick black carpet can look sharp enough to work, especially if they are mounted in some sort of pattern, and should work well to reduce some of the echo. It won't make the room sound like a recording studio, but it will help.

Better than that would be any sort of open cell foam. It would be better in this case to have more coverage of thinner foam than to have thicker foam with less coverage. Acoustic foam is really not any more effective than any similarly dense open cell foam, so don't worry about the expensive panels.

One solution that is very effective and can look very nice is to get some rigid fiberglass panels (they come in 2'X4' sizes) and cover them with a nice cloth. Mount them to the wall and they look almost like artwork, although it is definitely a bit of a DIY project, so I don't know if that is an option.

If you are in an artsy place, hang a rug or some thows on the wall. That will help. If you are not in an artsy environment, though, that probably won't go so well.

For smaller rooms designed for speech, the important thing is to get a good amount of coverage. You won't have to worry about lower frequency buildup, so you don't need anything super thick or high tech.

Any fabrics will help, and creating a dropped ceiling with fabric could help, as long as the fabric was thick enough to absorb some of the sound (a bed sheet likely wouldn't do much)

In the end, anything soft will help. As a general rule of thumb, if you can blow air into it, it will absorb sound. If you put foam or fabric up to your mouth and blow, the air will go into it. If you put foam rubber up to your mouth, you can't blow any air into it, so it will not do a good job at absorbing sound.
posted by markblasco at 11:49 AM on August 19, 2008

Yes, the room is really 6'x8' with an 18' ceiling! This is an office in Manhattan, so wierd space compromises were made in order to squeeze a private conference room into an open loft-style space.

Is homasote super cheap like cork?
posted by ben242 at 11:54 AM on August 19, 2008

Seconding the ceiling space being the biggest source of issue. Try bringing the height down with cloth or some absorbent material as a first step before making the walls look hideous
posted by Brockles at 11:58 AM on August 19, 2008

Quarter-inch thick cork is probably too thin to be very useful; a 3/4" thick cork panel has an NRC of between 0.10 to 0.15 -- and that's three times as thick. By way of comparison, bare steel is 0.0 to 0.10.

Your conference room is probably behaving like a resonator, so the folks above suggesting ceiling coverings are on the right track (IMHO).
posted by aramaic at 11:59 AM on August 19, 2008

Seriously? Hang curtains. Great noise deadener, cheaper than nailing up cork, and it won't look like crap. (Assuming you pick out half-way decent curtains.)
posted by Citrus at 12:00 PM on August 19, 2008

I would also recommend curtains.... urtains.... tains.... ains... ns...

With the caveat... aveat.... veat... at...

That you should cover two adjacent walls.... alls... lls... ls...

For example, the northern wall, and the eastern wall... all... ll...

Or the eastern and the southern.... outhern... thern... ern....

Or the, oh, you get it, the 90 degree angle trick will reduce most reverberation past one or maybe two bounces.
posted by mark242 at 12:08 PM on August 19, 2008

I can't lower the ceiling because there is a sprinkler head mounted way up high. I don't have the funds available to lower the head and violating the fire code is definitely not an option here.

I work at a rapidly expanding dot com; thats why ultra-cheap is a factor.

There are plenty of places in Manhattan that sell carpet tile and custom-cut remnants so I'm investigating that a bit more. Looking into just hanging an area rug too.

Curtains or drapes would look really wierd in this room and my boss has specifically vetoed it. If it turns out that carpet is for any reason impossible or prohibitively difficult or expensive, I'll return to that idea.

BTW - thanks for all the great ideas here folks. Much appreciated.
posted by ben242 at 12:28 PM on August 19, 2008

Put up the largest possible whiteboard on one of the walls, but mount it so that one side is a couple of inches away from the wall. That will help a bit by reducing the mirror effect between the two no-longer-parallel walls.
posted by bricoleur at 12:50 PM on August 19, 2008

I think it might be a bit out of your price range, but felt is really effective for this purpose. I'm not thinking of curtains - more like getting thick felt and covering a wall or two with it.

Maxwell at apartmenttherapy.com made doors out of felt a few years ago and left this post about it, which has a couple suppliers listed on there. Maxwell's felt might be a bit more than you need, but I'm not sure.

There's also the carpet tiles that you mentioned - some FLOR tiles, for instance, might work better than cork. Not QUITE as cheap, but probably cheaper than the felt.
posted by andrewmarc at 2:44 PM on August 19, 2008

seconding bricoleur

old houses sound better without furniture than new ones because the walls aren't plumb/square. if you can set one wall or the ceiling 1" out of square somehow, your problems will likely go away completely.
posted by KenManiac at 3:40 PM on August 19, 2008

I bought my panels like a year ago and can't quite remember but, maybe $30? I really don't know. At homasote.com they have a zip code lookup for where to buy -- a quick phone call should sort it out for you. Homasote ideas: http://www.apartmenttherapy.com/ny/search?q=homasote.
posted by amanda at 9:32 PM on August 19, 2008

A third of bricoleur, with the addition that if the fire sprinklers are "normally" hung (eg, 6-8" from the ceiling) you can do this same trick at the ceiling level: install something ceiling-colored above the sprinklers that's 1-2" out of parallel (you could even do it in 2 sections and make a peaked roof). On a side note, years ago I took an acoustics class from Amar Bose and heard his story of how many contractors/waivers/entreaties/etc. it took before he could convince a reputable carpenter to build him a media room that was 2" out of square all the way around.

I'd also pay attention to what's actually present in the echo, because you may be able to selectively attack it. Rather than try to paraphrase I'll just suggest resources like this, which discusses room modes in (maybe too much) detail. If you can figure out what frequencies are reverberating, you can know which surfaces need the most attention.
posted by range at 1:57 PM on August 20, 2008