i 2 like the bigger subs.
Headunit: Pioneer AVH-P2300DVD
Subwoofers: (2)15" RE Audio XXX(05 model)
Sub Box: Undecided..
Sub Amp: Crescendo bc3500
Speakers: 6.5" RE Audio XXX Components(soon to be 2nd pair in kick panels)
Speaker Amp: Hifonics HFi100.2(for now...)
Wiring: 2 runs of 1/0 throughout, XS Power battery in trunk,big 3 done, 270a alt, 1/0 accesories throughout
Deadner: 75sq ft AT 60mil, 20sq ft Alphadamp
Security: Crimestopper 2way alarm/remote start
(b):hoxie08, dacheatham, RetroAudioInc, pro-rabbit (t):dave_damage, j.clark90
subs-Sundown Nightshade v1 18's
Amp-AQ 3500d.1 (running 1/4 ohm daily)
electrical-1/0 tsunami everything, yellow top up front, 4 deka intimidator 9a78dt's behind the front seats
enclosure-10 cubes at 35hz
Best tl score to date-154.1 (hoping to see 55's soon)
Subwoofer size and Fs are only two aspects as to how low a sub will play, and not even the most important. Box design is the most important factor in how low a sub will respond.
Within the same sub line using the same motor, the larger sub is going to have a lower Fs, higher Qts, higher Vas...basically the larger it gets the better it will work in a sealed box compared to its smaller counterparts. Some beefier subs such as the BL, BTL, etc can still maintain a lower qts and vas value that will still allow the larger sized subs to be very capable ported box woofers.
This isn't 100%, but a pretty good generality.
Loudness is determined by alot of things not just size of woofer. If you have a 10 that is in the proper enclosure tuned closer to the resonant frequency of the vehicle with less impedance rise. The ten will be louder than a 15 on a improper enclosure tuned to the wrong frequency.
Assuming you are buying a properly designed woofer, have decided on a make and model, and can build a proper box, size is only relevent when deciding how much cone area you need. The tradeoffs from there are how much power you need to handle (more smaller woofers will handle more thermal power than few larger ones) and box volume (larger woofers need larger boxes to function properly).
lot of bad info here.
As I said in another thread earlier, is it fair to say heavier cars tend to be slower than lighter ones? Logic tells us lower moving mass will respond faster, so it should stand to reason that lighter cars are generally faster than heavier ones. But this leaves out some crucial details, like power applied to that mass.