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lpd
02-22-2013, 09:11 PM
How would a 2231a do in a box 5.7 litre volume box ported?

kawmic
03-23-2013, 11:52 AM
It wouldn't work at all. Recommended cab is: 85.4 liters @ 31.2hz with a 102mm dia tube 215mm long

Lee in Montreal
03-23-2013, 01:07 PM
How would a 2231a do in a box 5.7 litre volume box ported?

Do you have the T/S parameters and what frequency will you port?

speakerdave
03-23-2013, 01:09 PM
How would a 2231a do in a box 5.7 litre volume box ported?

Do you mean 5.7 cu. ft.?

Lee in Montreal
03-23-2013, 01:16 PM
Do you mean 5.7 cu. ft.?

I suspect he did mean cft, not litres. if the 2231 behaves like his sucessor, the 2235, then 5.7cft (160 litres) is perhaps just right, tuned to 27Hz.

The 2235 has a Qts=0,252 of and a Vas=460litres and according to the formula where 5.7 is supposedly the best alignment for sound, then Vb = 5.7 x Vas x (Qts^2) = 166,5 litres.

Then make a simulation with this volume. Change it up and down and see how the response and excursion behave. It's always a matter of compromise.

Here's JBL's POV on this driver
http://www.jblpro.com/pub/obsolete/2231a.pdf

And the T/S specs
http://www.jblpro.com/BackOffice/ProductAttachments/Theile_Parameters.pdf

Qts = 0,21
Vas = 736,2

Then Vb could be 185 litres for best extension without being underdamped. Maybe with a port tuned a bit higher than a 2335. What about 28-30 Hz?