That's a neat looking little sub, but it'll be at such a disadvantage in terms of raw physics. Even a low cost 8 inch sub is going to dig deeper and louder... Any reason why you want such a small driver?
Yeah there are a few considerations (there are tons, but these are my most important):
1 - volume of air moved (cone diameter, excursion)
2 - low frequency range
I'm part owner of a headphone company (thinksound) and know a bit about audio, but that doesn't extend to car audio for the most part...some principle are consistent but the environment is completely different. The way I approach the above is:
1 - There's no way around this, the little guy is smaller. It does have a ton of excursion though, so pushes more air than other small subs. An 8" would move more though, no question. I'm not too concerned about this, since the cabin is so small - compare the Emira cabin size to a sedan, and it's pretty clear that the relative air being moved by a little sub is far greater than a big sub in a big car.
2 - This thing hits 35Hz! That's kind of perfect and you'd have to go 10" at least to get lower (in the Focal range for example). Below 30Hz would be great, but I'm more a fan a tight bass vs thumping bass, and I feel that tight controlled sound is more aligned with the spirit of a sports car: precision sound for a precision car. Also, since I'm going to run a DSP, I can extend the frequency range a bit lower than 35Hz.
3 - loudness. Everything will be loud enough, this is a non-issue.
I run an 8" sub under the seats of my old Defender 110 (so 2 total) and they are absolutely perfect: punchy, precise, and you feel it in your chest if the bass is turned up even a little. That experience changed how I plan out audio installs. Full transparency, if I can fit this instead, I probably will:
https://www.crutchfield.com/p_091SUBP20S/Focal-P-20-FSE.html?tp=111
I mean, who knows what it will actually sound like...I'll have to install it and report back - car arrives in August...so be patient
