Sound Insulation - Please Comment

[Soliton]

Hey Guys,

Because of small room restraints, my drums are setup in a small corner surrounded by bare walls. You can imagine how bad cymbals and OH's sound. Yuck. But this is the only spot for them, so please no replies saying move the drums and find the sweet spot.

My plan is to line both the walls and ceiling with convoluted foam. I've been searching around the "cheap" places (moving companies, mattress stores, etc.) but since they don't have what I want, I had to start looking at real audio hardware retailers.

I'd like some feedback on this product. It isn't egg crate style, but just plain and flat. Here are the tech specs.

It goes for $55 (45 USD) for 30 square feet, I guess that price isn't too bad?

a) Would this material do the trick? Or should I stick with my original plan of convoluted, egg crate style (because there's more surface area, it absorbs more?)

b) Is this priced ok? With taxes and the stupid $20 adhesive, it's about $90 (70 USD) - seems a bit high.

Any other suggestions on how to reduce high end reflections for minimum costs would be nice. The deader the better.

Thanks!

[Soliton]

I'll be reading over here in the meantime:

http://www.johnlsayers.com/phpBB2/index.php


But I'd still like some feedback here. Thanks.

[weedmaker]

This is a very broad subject and without being actually there on the spot, it is very, very hard to give any valid advice! But I'll try to help here with general advice, anyway.

First, what is the construction of walls and ceiling/floor? Is it masonry or drywall, concrete or wooden floor/ceiling?

Your goal is to absorb uniform amount of sound energy across as broad sound spectrum as you can. Drywall and wooden floor are generally your friends in small rooms - they absorb low frequency energy, below 500 Hz, which is very difficult to achieve (expensive and bulky) with porous (foam) type of the absorber!

So using only foam without paying attention to low and low-mid frequencies, especially if the walls are solid masonry could result in uneven reverberation freq response - cardboard and muddy sounding drums are very possible!

The best thing is to find someone knowledgeable about acoustics; otherwise try to add absorber in increments, than record some drums, than compare, add some more ... Also avoid to have one big foam patch, it is better to lay the foam in checkered pattern (diffusion is better that way).

It's very easy to add too much high frequency absorption, so be careful!

Try to Google "acoustics" for more information!

Good luck!

[Ethan Winer]

Tom,

> Here are the tech specs. <

That stuff looks okay for 2-inch foam, but 2-inch foam is not much of a solution because it doesn't absorb enough at lower frequencies. So what usually happens with this type of treatment is the room becomes too dead sounding, yet it's still boomy. For a vocal booth that might be okay, but not for a room where you'll record drums.

--Ethan

[captain54]

I have had the same dilemna in my drum room, and had tried a number of treatments, the worst being lining the walls with acoustic foam....

also, if you are set up in a corner, you need to seriously address the room corner, and basically every corner in that area where the wall meets the ceiling....

the only advantage to lining walls with foam in a corner, is if (as someone said), you convert it into a vocal booth....all the higher end frequencies that drum mics, (more specifically overheads), need to capture are being sucked out and diffused by the treated corner.... your drums get reduced to cardboard boxes...on top of that, all the low end is being sucked and trapped into the room corners, and what you have is a mess on your hands....

in my experience, I found treating the ceiling with some sort of thick cloud of fabric or foam helped eliminate some phasey weirdness that was happening....a hardwood floor or some kind of hard wood paneling underneath the drums might help also..

the trick is to try to get the drums sounding as natural as possible, to recreate as close as possible to what your kit actually sounds like....I'm not an expert, nor even an engineer....just spent countless hours experimenting, trying to get the best results on modest gear....it's not easy, but it's not rocket science.....

[tINY]

Have you tried recording with PZMs as overheads?



-tINY

[brianroth]

As a side note....BEWARE that many cheap foam products are very flammable. Anyone recall the "Great White" disaster in Rhode Island?

Bri

[Anderson]

Don't use foam... It's a waste of money and will not solve your pb, juste create another. dfegad Forget all those foam and supa-foamy-bass-trap stuffs. Plain Rip-offs.

If I were you I'd start by buying some MDF panels + rockwool, and get rid of that corner. You can work on the angles so that you achieve some kind of diffraction. Maybe build yourself a Schroeder Panel (not so hard to do) that you would fix behind the drums in the corner?

Posting some pics of your room will help!

Cheers

[brianroth]

yep, find a supplier of OC panels.

Bri

[captain54]

Originally Posted by Soliton

I really appreciate the replies.

ith that said, is foam still a shitty way to go? I'm mainly concerned about budget. If there's a solution for $75 USD, I'd do that over anything. Because like I said, this is just for screwing around at home.

Thanks for all the input.

if you are still set on foam, the only place I would use it where it's going to make any difference is a spot treatment above the drums on the ceiling...

other wise, you are wasting your money....

[eeldip]

foam has some great advantages:
its super easy to install, super easy to de-install.

for people who rent, and have non-pro studios, this is pretty important stuff.

foambymail.com has acoustic foam that, if it actually lives up to its specs, is decent enough and totally cheap.

for drums, i think the above advice is great. 4" pyramid foam spaced out on top. nice mix of absorbing and diffusing. only $25 for a 12 pack of the 1 foot square. might as well try it. very small time and money investment.

[eeldip]

well i am a big cheater. i attach the foam mechanically, as in i nail it up (i can feel around and unnail easily). which means that it will not perform as well as it specs. it needs to be very tightly sealed for maximum performance, but there is a hair of asstalking there.

i put that stuff up in my living room or whatever room needs it for tracking, then take it down for looks.

so, convenience beats out performace for my needs.

do you have a real studio? or i mean, a space that you use exclusively for recording? if so, check out the ethan winer site.... very informative, and his solutions are cheap.

[Ethan Winer]

Eeldip (great moniker, btw),

> foambymail.com has acoustic foam that, if it actually lives up to its specs <

Aye, there's the rub. The specs they show are fraudulent. This has been discussed in a few other groups lately, and you'll probably see more discussion soon. I recently paid to test corner foam from Foam by Mail and also from Auralex. Even though FBM claims identical specs, the lab measured only one third the absorption at 125 Hz and below.

--Ethan

[captain54]

Originally Posted by Soliton

Pretty nasty spot, huh?

Aside from foamin' up the ceiling, should any consideration be taken towards that lip where the wall meets the ceiling? The ride is like 4" to touching that corner - can't be good.

packing blanket (s) attached by hooks to the ceiling forming a "cloud" above the drums is a cheap solution....attach hooks beneath the "lip" to the wall, then the other side to the ceiling....

[eeldip]

Originally Posted by Ethan Winer

Eeldip (great moniker, btw),
> foambymail.com has acoustic foam that, if it actually lives up to its specs <
Aye, there's the rub. The specs they show are fraudulent.
--Ethan

well then, that explains the dirt cheap price...
thanks for the tip.

(curses foambymail)

[weedmaker]

Originally Posted by captain54

packing blanket (s) attached by hooks to the ceiling forming a "cloud" above the drums is a cheap solution....attach hooks beneath the "lip" to the wall, then the other side to the ceiling....

Soliton,

After seeing photos of your place I'll second captain54 advice! Try blanket first and listen to the cymbals again! The beauty of hooks + blanket is that you can easily take it off!

In addition, you can build (very cheap) couple of absorbing panels - 1 m (3 ft) high MDF or chipboard covered on both sides with thick foam/rockwool and wrapped in some cloth. Build some stands for panels and voila - dead local acoustics for almost nothing!

This should work great for demos & having fun, so don't overbuild!

Cheers

[weedmaker]

And that entrance to dead bodies room is free basstrap, btw

[Ethan Winer]

Eellie,

> well then, that explains the dirt cheap price... <

One of these days soon, after the results of my test circulates, I fully expect to see a large number of FBM customers get together and file a class action lawsuit.

--Ethan

[weedmaker]

Originally Posted by Ethan Winer

One of these days soon, after the results of my test circulates, I fully expect to see a large number of FBM customers get together and file a class action lawsuit.

Hi,

I think they’ll get away with false advertisement because there is no statement on what was the condition of NRC measurement – I can’t find it on their website.

They would probably argue that measurement was done with foam mounted, let's say 8" from the wall!

The only cure is to be very skeptical of any manufacturer claiming significant low frequency absorption from porous material applied to plain masonry wall - and NRC of .32 for ordinary 4" foam at 125 Hz is ridiculous!

Cheers

[Ethan Winer]

Weeds,

> They would probably argue that measurement was done with foam mounted, let's say 8" from the wall! <

But even that would be false because an 8-inch gap might help the low end, but it doesn't account for the poor absorption at higher frequencies.

--Ethan