A couple of questions about foam

[Canobliss]

1) Auralex etc usually make their foam with either the shingle or egg crate style design thus the foam is thicker in some place and thinner in others. They say this is for broadband absorption but wouldn't a piece that was two inches thich everywhere do a better job at accomplishing this?

2) Now that i have built my own panels out of 703, i have a lot of foam which i dont really need. It would actually look pretty cool if I attached it to the front of the fiberglass panels. How beneficial would this be for absorption purposes? should i just give it to a friend or sell the stuff for a few bucks?

3) I hate foam.

 

[Renascent]

If you hate foam, give it away or sell it. I'm sure theres plenty of people on this board who will buy auralex foam

Do you have a vocal booth? Foam is nice to use in there
Foam is a lot lighter than wood/fiberglass absorbers if your ceiling needs treatment
Got windows? It might be cool to get some 1/8" plywood and glue the foam to that, put it in front of the windows when you are tracking/mastering?
Just a few suggestions. If none of them fit, i'm sure you wouldn't have a tough time selling it if it's a good quality brand
good luck
Scott

 

[Ethan Winer]

Cano,

> wouldn't a piece that was two inches thich everywhere do a better job at accomplishing this? <

At lower frequencies Yes, and if the total thickness were more like 4 inches the difference would be less. Once you get to 2 or 3 inches thick you already have 100 percent absorption above 1 KHz, so thicker does not help further.

One reason sculpted foam is useful is it offers a more favorable "angle of incidence" to sound waves. When sound strikes a panel perpendicularly, more is absorbed than when it grazes off the panel at an angle. Think of a rock skipping over a lake when thrown at a severe angle. Sculpted foam has more "angles" so to speak, so it does work better, but only at higher frequences. You are absolutely correct that sculpting reduces the effectiveness at lower frequencies because of the thinner portions.

> It would actually look pretty cool if I attached it to the front of the fiberglass panels. How beneficial would this be for absorption purposes? <

It would help a little (very little) at the highest frequencies for the reason given above.

--Ethan

 

[Canobliss]

One reason sculpted foam is useful is it offers a more favorable "angle of incidence" to sound waves. When sound strikes a panel perpendicularly, more is absorbed than when it grazes off the panel at an angle. Think of a rock skipping over a lake when thrown at a severe angle. Sculpted foam has more "angles" so to speak, so it does work better, but only at higher frequences. You are absolutely correct that sculpting reduces the effectiveness at lower frequencies because of the thinner portions.
--Ethan

That makes perfect sense. thanks for clarifying that. Auralex and others need to re-word their descriptions.