Just a quick update since I've been running this sub hard for almost a month.
Absolutely love it. Sounds even better now than it did when I first installed it. Fits nicely behind the screen (barely). Really pumps out the nicest, lowest, cleanest bass that I've ever enjoyed.
I've got a bunch of music performances from Palladia that I've saved to a hard drive... plugs into the USB port on the front of my Sony Blu-ray player... Crossroads, Jools Holland, Unplugged, Live at Daryl's, etc. Great stuff.
I don't know if it's from cranking the sub or just the house settling due to the recent temperature changes, but I've actually cracked the seams between a couple of sheetrock panels on my walls.
Anyways, without knowing what I'm doing I ran my first tests in REW:
1) no subwoofer
2) one of my old 15" subs (Cerwin Vega LW15)
3) my other old 15" sub (DefTech Powerfield 15)
4) my new F20
5) F20 plus the stronger of the 15" subs (CV15)
The biggest surprise is that F20+CV15 has lower measured output than the F20 alone? Why?
Really nice build!
As for the mic, I have that one too, did you download and use the calibration file for your mic?
As far as I am aware, once the mic is calibrated the SPL measurements are accurate.