[marvda1]

would a roll of carpet padding make a good bass trap?

[Red Dragon Audio]

Probably.

Try it out in your room and report back.

[markC]

I don't think so. You need the density of fiberglass to absorb low freqency. Foam may work for upper mids, but I don't think it will be too effective in the bottom end.

[Red Dragon Audio]

I don't think so. You need the density of fiberglass to absorb low freqency. Foam may work for upper mids, but I don't think it will be too effective in the bottom end.

That's not entirely true.  Fiberglass comes in a wide array of densities.  Typical pink stuff is not dense at all but "rigid" fiberglass panels can be quite dense; usually anywhere from 2.00 PCF to 6.00 PCF.  The pink stuff makes a good bass trap when it comes in the big bales; which are compressed quite a bit.  That increases their density and therefore their ability to absorb bass.

soo...

I think the trick with carpet padding is that when you roll it up, try to compress it as that will increase the density somewhat.

[arthur]

i put a couple of large bales of insulations fiberglass in 2 corners of my room still packed in their original packaging. i covered them with some thin padding and wrapped them with burlap. this has done the trick to tighten the bass.

try just buying a couple of bales from Home Depot and try them at home - if it does not work than you can just return them and get your money back. BUT make sure to wipe them down with wet cloth and put them in large plastic trash bags before putting them inside your car. you don't want the fibers under your skin nor in your lungs.

[markC]

That's not entirely true.  Fiberglass comes in a wide array of densities.  Typical pink stuff is not dense at all but "rigid" fiberglass panels can be quite dense; usually anywhere from 2.00 PCF to 6.00 PCF.  The pink stuff makes a good bass trap when it comes in the big bales; which are compressed quite a bit.  That increases their density and therefore their ability to absorb bass.

soo...

I think the trick with carpet  ...

Yes, you are quite correct about the compression thing. I used 3 15" wide rolls stacked in their original packaging wrapped in burlap. I have 1 in each corner of my listening room and am pretty pleased with the results.

[Roc]

marvda1,

I used  6' tall rolls of 8 pcf carpet underlay foam as bass traps for years.
Used them just the way they came.
I put a full roll in each of 4 corners.  
They do an excellent job!
Actually they were an overkill.
Paid $65 per roll.

As an experiment I cut the rolls down to 4 ft. length/ht.
And I re-rolled them over a 10" diameter mandrel to make them tubes.
Of course I removed the mandrel.
4 ft tubes work almost as good as the 6 ft solid version.
And the left over 2 footers can be made into a third trap.

Since then I made my own corner traps using 3.5 pcf seating foam.
These go floor to ceiling.
I have my own patern for the front surface contour.
I'd tell you about it, but I'd have to kill you.
These work almost as good as the 4 foot tubes as bass traps, but the overall sound is better since they reach up to the corners.
They also provide a small amount of diffusion.

Dave