I own a first generation 8inch Kicker Solo Baric (S8 I believe?)

These are car audio subwoofer speakers.  I believe the "Solo Baric" were engineered as a single woofer that acts more like an "isobaric speaker arrangement".  Isobaric is when you place two woofers face-to-face and mount them in the box like that.  As a result, a "isobaric configuration" will require less box volume, hence a smaller box.  I think the Solo Baric was one of the first "small box" subwoofers that have been manufactured over the years.  There were several models of the S8 made with different Thiel/Small parameters (i.e. S-8-4a, S-8-8a, S8-D2, etc.).  They are all available to view in the Bass Box Pro software database.   If you can identify an actual specific model number, I can paste the specs for you.

Thanks that would be great! Its model S8-4a

FS: 34.9 Hz
Qms: 8.72
Vas: 0.886 cu.ft.
Mms: 1.785 oz
Xmax: 8.45mm
Sd: 211 sq. cm
Qes: 0.436
Re: 3.55 ohms
Le: 0.525 mH
Z: 4 ohms
BL: 9.6 Tm
Pe: 300 watts
Qts: 0.415
SPL: 86.2 db / 1 watt