6.5 speakers (pictured below)
Paper Cone
subkicktest_papercone.mp3 (graph right below) seems to have more air to my ears, I preferred this one
Polypropylene Cone
subkicktest_polycone.mp3 (graph left below) seems a bit harder might be good for metal
Kick Tracks use no processing drums aligned for phase and time using Sound Radix Auto Align. The inside kick mic which is blended with both is a CAD KBM412. Preamp used was a Focusrite OctoPre going into a Digidesign 192 Digital via ADAT lightpipe at 44.1 into Pro Tools 12.6 HD (W/C is Apogee Big Ben). Guitar and Bass using Bluecat Destructor plugin which is the bomb!
Papercone is first 2 images, Polycone is bottom 2 images
Other companies that sell Subkick mics
MDB Northwest Music Deep Kick (sells mostly ebay $150)
https://reverb.com/item/1297892-deep-kick-premium-edition-subkick-microphon
SOLOMON MiCS - LoFReQ - Sells in retailers ($200-$250)
http://www.solomonmics.com/specifications/
DW Drums Moon Mic - $399
http://www.dwdrums.com/moonmic/
Note: popular Yamaha subkick is no longer made/sold and getting harder to find used. Old NS10 woofers are a popular DIY choice for subkick mics