Quote Originally Posted by Altec Best View Post
I think the 6" pvc would be pretty easy to do paint them black.But I would need 2-3 of them would I not to equal the port dims givin.

And would the length still be the same 4" if say 3 tubes were used ?
If you work out the pipe's cross sectional area (CSA), (2) 6" diameter pipes have a bit more CSA than (1) 8" diameter pipe, so one on each side panel is plenty and I'm hoping the extra acoustic mass loading of these short conic horns that the cab, floor plus two walls creates will reduce the longer calculated vent length to around 4", but they may need to be longer if a true 25 Hz tuning is desired.

Since the lowest note on a piano is 27.5 Hz though, this is all you need unless you decide to drive them with a very high output impedance amp which in this case will require tuning the cab to the mean of the two driver's actual Fs.

With these somewhat acoustically small cabs, any organ pipe symphonies with < 20 Hz output are best played with plugged vents and use EQ if necessary to flatten the system out.

GM