Maybe this is the first real REW 4.0 graph posting.

Here are my measurements of the
sealed sonotube subwoofers I built a while back. For those who didn't follow the earlier thread (I've also posted the graph there as well) these are four 15" TC-2000 SVC drivers in two 20" diameter 4' high sonotube enclosures powered by a Behringer EP2500 and boosted/filtered by a Behringer DCX2496.
I used an ECM8000 with Sonny's calibration file, extrapolated to -12dB at 5Hz.
Thanks, John, for building this program that let me reliably calibrate my subs. I guess the donation I made back on version 3.0 did help a little.
