Originally Posted by AndreasMergner
rwaaudio: Your enclosure is similar to others that were built by Thigpen. I'm wondering why they are so large and what compromise I would be making if I went to a 2'x2'x15' enclosure with one bend. I would think I would get much better reduction in fan noise, but wonder what the performance hit would be.
As far as the back volume, I have read mentions of only 1/4 of the HT needed. It will affect the frequency response, however, similarly to an IB vs a sealed traditional sub. Maybe "similarly" is not the right word, but it will increase some freqs and decrease others.
Steve: I will have no problem hacking through that driver. I am no expert on driver construction, so I will need to see it to determine how I will attach the linkage. Hopefully, I will be able to get some help on how far I need to (or can) strip the driver to get something secure to mount to without destroying the driver. Considering it is a "free" driver thanks very much to Penngray, I don't mind putting in some labor and thought on how to do it.
I will be using an arm and clevis with the clevis pin going through a bearing....I don't mind experimenting a bit though. I want to keep it as light as possible to ensure good high freq response.
A minimum of 3' x 3' vent opening is required and 4' x 4'
is better, 5' x 3' would suffice. The opening should be
close to 1:1 ratio with the opening cross sectional area
carried through the entire enclosure. The length of
the enclosure should be 6' to 8', but not much longer as
this could cause turbulence. One bend is also required
with a 3' turn up to the floor.
For maximum output a larger volume than the room is required for back venting.
No enclosure is best for maximum output, but with fan noise that would be very high. A picture of my friend's rotary sub
shows no enclosure (testing only) and this gives more output,
but high noise.