Box volume/Acousta Stuf Question

[peregrin288]

I am working on my first build, which is Matt Phillips' Millennium III project. Matt states in his write-up of the build that the woofer cabinet (using two HiVi D8 drivers) is 2.1 cubic feet after subtracting driver displacement.

Should I be using acoustic foam on the inside walls or Acousta Stuf? I've seen directions for using one or the other, directions for never using Acousta Stuf in a vented box, directions for only using foam on the inside walls, directions for using both, etc.

If I should be using foam, do I need to subtract the foam from the box volume as well?

Thanks for any and all help.

[billfitzmaurice]

Re: Box volume/Acousta Stuf Question

Line a ported cab, stuff a sealed cab.

[peregrin288]

Re: Box volume/Acousta Stuf Question

Thanks.

Do I need to subtract the foam from the box volume? I would need to make the box slightly bigger if this is the case.

[Jeff B.]

Re: Box volume/Acousta Stuf Question

Thanks.

Do I need to subtract the foam from the box volume? I would need to make the box slightly bigger if this is the case.

Open cell foam doesn't take up enough volume to worry about unless you start packing it in and compressing it. If you are lining with it, then you don't need to adjust the volume.

[peregrin288]

Re: Box volume/Acousta Stuf Question

Thanks a lot, that answers my questions.

I'll post pics of the build as I progress.

[Pete Basel]

Re: Box volume/Acousta Stuf Question

Do you have a copy of the LDC? There is a damping study in there that is quite interesting. Seems to show that foam makes the box look bigger as does any fill that pushes the system from adiabatic to isothermal conditions. This of course only happens for the air around the foam so the effect is very small when the box is just lined.