^ You're right to a certain extent. A couple of $100-150 tens would be all that is needed in almost any SQ system.

^^x2, one of the nicest sounding systems I've had just used a single 12" kicker cvr getting 160 watts rms in a large (2.4 cubes) ported box tuned to around 33hz. It got more than loud enough to shake the mirrors, and move the seats...but it sounded really good overall...kind of like a good pair of headphones..very balanced.

Best SQ sub? I love my 18" Focal 46KX4 in a 5.5 cu.ft. ported enclosure tuned below 30hz. Not saying there aren't other good options, but I challenge anybody else out there to show me a sub that plays as low, loud, and accurately as that thing. Crossed over at 51hz at 24db/oct. for anyone who cares. And I'm sure we could squeak one of these into a Mazda without giving up hardly any space, :cheeky4: !!!

^^ Ya, five and a half cubes in a Mazda, you won't even know it's there, totally stealth.....

I read a sealed box is better than ported for SQ ?
Also, dont get a sub bigger than 10"'s 12's and 15's are sloppy.

^^not true on both accounts...has much more to do with box design and system set up than woofer size and box type.

I helped judge a couple of cars this weekend....and this is what I learned...
First as a sales guy, what kind of music do you usually enjoy...and don't say everything...be honest with yourself and the sales guy (I hate country and it falls under the catagory as "everything". This is important because a ported 15" on classical music makes about as much sense as techno on an 8" sealed.
Also if your competing the system, then the specs of a sub in a sealed box is the way to go...Why??? Because you want a sub with a flat response from 20 -120, and hopfully you have a pair of mids to pick up from there. When systems are being tested, how does the sub respond to a low 20-25hz foot stomp, or a 60-80 bass kick...Do you hear it??? So check the specs, if you want a true SQ performer, all subs perform different and all boxes do as well. By the way my two cents I am not a physics guy but, 15" subs do move more air than 10s thus creating more sound pressure which = more annoying bass.

Define flat :dunno:

OK....my understanding of flat and correct me if I'm wrong. If a sub is testing 90 db at one watt one meter on a spectrum meter, it should not spike at certain frequencies... One note wonders ie. bandpass boxes, are not good for SQ, therefore a flat response will win in SQ competitions, because the sound curve is slight, and the slope is suttle no more than a 12db / octive...The tighter the sound the better the points in SQ...Although I like to build stuff that is fun, and a sealed SQ sub is not a nice sound in my opinion. I like to feel the bass, and so I tune most of my stereos to enjoy techno....but to the "judges" its about what can be heard.

Since our hearing becomes less sensitive as the frequency decreases, would it not make sense that a system that had a rising response as it got deeper would sound more 'flat' or 'even' than one that looks flat on a meter? I think so. And for sure while vehicle transfer function helps in this respect, I find that sealed boxes still seem to sound a little on the light side in the bottom two octaves. I contend that a vented enclosure with it's low peak perks up that bottom end and makes things sound more solid and even overall.

See where I'm going with this?