Subwoofer Stuffing?

[moves]

For sealed enclosures you need to fill the cabinet with the stuffing, but there should be absolutely no compression of the material.

Polyfill I have used without trouble and is probably best for TLs.

So no compression means stuff the polyfill loosely correct?

What is TLs?

 

[moves]

It isn’t changing the internal volume because rockwool is semi permeable. It’s not different than stuffing so it doesn’t change anything, it’s just more effective at dampening reflections and vibrations while taking up less space. However, it’s much more expensive and annoying to work with, so I use as little as possible and simply line the walls and cover with grill cloth. A cost no object sub, I’d cut the rockwool into smaller pieces and individually wrap each with grill cloth and stuff with those in addition to lining.

I like the polyfill go free. Most of the big manufacturers do the same and they and I have never run into an issue with this. I even built a sub with rockwool and didn’t cover or line it and it still worked fine for over 5 years until I pulled the driver to rebuild.

Awesome I will do that..... what is polyfill go free?

 

[fuzz092888]

So no compression means stuff the polyfill loosely correct?

What is TLs?

You generally don’t want to compress the material, which is why using a denser material to begin with is sometimes desirable.

transmission line. An oversimplification is kind of a cross between a port and a horn. Transmission line’s can be straight or tapered and bent.

Awesome I will do that..... what is polyfill go free?

The cheapest polyfill is the pillow stuffing from walmart which is like $25 for 10bs. 10lbs is A LOT of polyfill because it is so light and fluffy. I would actually compress this stuff a little because of its lack of density. There is actual acoustic polyfill and that is similar, but definitely denser. I read an article once where they measured the differences between a bunch of different materials and their absorbtion properties and pillow stuffing works ok, definitely not the best, but its workable.

 

[TLS Guy]

It isn’t changing the internal volume because rockwool is semi permeable. It’s not different than stuffing so it doesn’t change anything, it’s just more effective at dampening reflections and vibrations while taking up less space. However, it’s much more expensive and annoying to work with, so I use as little as possible and simply line the walls and cover with grill cloth. A cost no object sub, I’d cut the rockwool into smaller pieces and individually wrap each with grill cloth and stuff with those in addition to lining.

I like the polyfill go free. Most of the big manufacturers do the same and they and I have never run into an issue with this. I even built a sub with rockwool and didn’t cover or line it and it still worked fine for over 5 years until I pulled the driver to rebuild.

The issue with damping material is not actually volume, it is the heat coefficient. It adsorbs heat and compression and gives it on release and so damps the changes in the pressure waves.

Now the problem with stuffing is that it tends to settle over time.

Glue should NEVER be used as it adsorbs widely into the material and makes significant portions of it solid.

I use netting to hold the polyfill in place and staple the netting to the cabinet. This solves both problems.