Advice on sonotube with a 15" PPI car sub?

[cjsmith]

I've been reading about the sonotube subs, and I'm wondering if I could build one with a sub that I have lying around. This is an older car audio sub - Precision Power (PPI) Pro 15, flat piston. T/S, that I found from WinISD, are posted below.

One of my concerns is Fs. After plugging into WinISD and pumping up the tube volume and tuning to around 22Hz ... dropoff at 16hz was about -12dB - how would this compare to the other setups?

Any thoughts on whether it would be worth the effort to try and make this thing work or ditch it and go with one of the known good configs?

Qts = .31
Vas = 108 l
Fs = 31.0 Hz
Xmax = .006 m
Z = 4 ohm
SPL = 90.51 dB
Pe = 600W
BL = 18.73

[WillyD]

I'd be more concerned about the extremely low excursion than the Fs. 6mm is way too low.

[ThomasW]

It's a woofer, trying to make it function as a sub is probably not the best idea