I have some large 3 ways which I just dropped the JBL M252-8B into. the port on this is rated at mach .24 and 32hz. When I play any kind of sine wave below 50 hz or so, the port is hideously wooshy, you can't hear it that much in normal music, though it's rather loud on some R&B.

The other PI models, like you said, are smaller cabinets with bigger ports, so it's not really an issue.

Has anybody tried a different port configuration, but with the same tuning?

Honestly, I think the program is wrong, or something has been entered improperly. The airspeed is nowhere near 260 miles per hour, even at fb and full power. I don't think it exceeds 60-70 miles per hour, which is low enough you can't hear any turbulence. It has never even been close enough for me to investigate.

I was just suprised my the amount of huffing when I played the M252's at real low in a box tuned to 32hz.

Anyway, those M252's sound pretty good, not quite as quick (read punchy) as the EV 15TRXB's they replaced (the M252's have a heavier cone and stiffer suspension), but a few Db more efficient and can take a heck of a lot more punishment.

Question, How does one filter out all below resonance information? would I have to get an active crossover? or would I have to make a real steep passive filter.

Thanks,
Danny