why is foam bad?

C

cantthinkofname

Active member
i've been researching accoustics and keep hearing that foam is bad although haven't heard why. is it, and if it is why? Thanks in advance
 
It's not *bad*...it just doesn't cover the entire frequency spectrum.
So...if you load up on nothin' but foam, you mainly kill off your mid-highs/highs...which then gives you a skewed frequency curve for you mixing.

While mid highs/highs can be problematic as early reflections...the bigger problems are the lows...and foam does little or nothing for them.
Most smaller rooms have problems in the lows.

You would want good bass trapping...some diffusion...some "live" wall space...and some early reflection control.
 
cantthinkofname said:
i've been researching accoustics and keep hearing that foam is bad although haven't heard why. is it, and if it is why? Thanks in advance
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The point of most typical (broadband) acoustic treatments are to absorb and prevent sound wave reflections. Foam only does this very well in the higher frequency range, and most seems to do almost nothing in the low range (despite what their marketing department may claim). This is particularly problematic when you consider that most home studios (or any small space) has it biggest problem in the low range, and foam just isnt a good choice. Rigid fiberglass or rockwool perform much better in the low end of the frequency range, and its cheaper. So, win win.

There are a few guys here that can really get into the technical details... Maybe they'll stop by. :)
 
thanks, i didn't know what the reasoning behind it was, avoiding foam seems to be something i'm going to do


if more stop by with more details, that would be great, i really appreciate your help thanks
 
foam isn't bad, but guys lining (close to 100% coverage) their room and then saying they've treated their room or even better, they have a dead room, is bad.

but don't tell them, because they will argue with you all day long and then go on about how great and balanced it sounds.
 
As in most things about recording "bad" and "good" are very subjective. I read one article (I think it was by Ethan Winer) that said if you are working in a very small room (10'x10' or smaller) that completely deadening the room isn't a bad thought. I believe the idea behind this is that the room is so small any reflections, standing waves, etc can through your mixing out of wack. Having a totally dead room results in a very unrealistic sound which can contribute to a skewed mix as well. Now, please, don't take everything I say as gospel. This is information AS I UNDERSTAND IT. Someone may come along and say "nate is wrong and here's why." I'm ok with that. But I hope this helps.



-Nate
 
A general idea is if you have a small room or a bad sounding room, deaden it and add artificial reverb later. If its larger and treatable, than having a nice live sound is the way to go.
 
Sonixx said:
foam isn't bad, but guys lining (close to 100% coverage) their room and then saying they've treated their room or even better, they have a dead room, is bad.

but don't tell them, because they will argue with you all day long and then go on about how great and balanced it sounds.
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Foam has very limited use in a home studio (I dont have a single piece in my studio, and that wont change anytime soon).

The problem is, people line their room with foam (or even worse "egg crate") and the foam sucks all the highs out of the natural room sound (which sounds, well, un-natural). But, it leaves unaffected the bass frequencies that were really the problem in the first place. So you have a room that sounds dull and a low end with some frequencies super hyped and some frequencies completely absent. Not a good sound.

foam has poor performance where it really counts and ITS MORE EXPENSIVE. :confused:;)
 
But you can't just use bass traps and diffusers and nothing else? Or can you? The lows will be out but what about the highs and mids?
 
saads said:
But you can't just use bass traps and diffusers and nothing else? Or can you? The lows will be out but what about the highs and mids?
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I think the orginal suggestion also included broadband traps. Those tame the mids and highs.
 
saads said:
But you can't just use bass traps and diffusers and nothing else? Or can you? The lows will be out but what about the highs and mids?
Click to expand...

A common bass trap design is 2' x 4' rigid fiberglass in a 1x4 wood frame, wrapped in cloth, spanning diagonally across the corners of the room and mounted on walls at the first reflection points... Also very effective in the mids and highs. So, I stand by my initial statement. NO need for foam EVER. :D Fiberglass is better in every regard. :)

Do a search. There are a million how-to threads around here, with plenty of pictures too..
 
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I'll just point out that are different types of foam...and they don't all work the same.

I have some Illbruk-Sonex on my nearest 2 walls...but it's not that "egg/ripple" bare foam stuff you usually see in mags. This cost a few $$$, and it is a heavier/thicker/denser foam with a thick cloth top. It’s very similar to the rigid fiberglass…just more refined in feel and ready-to-mount quality.
(I hate fiberglass…that stuff is not safe to breathe in.)
It was used to remove the early reflections from the nearest walls which aids in creating more depth by artificially “pushing” the walls back.
Then I have a couple of other types of treatment on the back wall and my ceilings...but there's also a good amount of live wall/floor/ceiling...that way, the room is quiet but not dead, and with a good deal of diffusion.

I could probably add a bit more bass trapping…(like Ethan Winer says) you can never have enough bass trapping, but then there is also the aesthetics and layout of the room to consider.
I mean...you may gain a bit in sound quality by lining your entire room with bass traps...but it's just not conducive to a friendly/comfortable working environment, so you have to do a bit of a balancing act between sound, comfort and having a pleasant working environment.
I went for good sound, which IMO I think a have, with minor quirks…but above that, I wanted a comfortable and nice looking studio…so there may be a some acoustical faux pa! :D
 
The best use I have for foam around the studio is for padding. I wedge pieces of foam between anything that rattles. This cuts down on some unwanted noise such as ratteling drums (where say a tom touches the bass drum) or other pesky viberation. If you have hollow doors you can glue dense foam to them to lessen the boomy resonance. For acoustic treatment foam has very little usefullness imo.
 
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