They do look pretty similar and I'm sure would perform better than your average ~$200 woofer. One thing to keep in mind is that the car audio SupremO 6.5 is designed to work in a door so there is higher qts of .57 at 60 Hz vs the .29 at 40 Hz of the SupremE. Lower q means it will have higher damping around its resonant frequency. In other words, the SupremE will have a smooth gradual low frequency roll-off, but will lack midbass resonance compared to the SupremO. Normally, you'd put a SupremE in a box to add back this resonance and punch.