You may need a larger aftermarket amp though. I find it hard to believe that that tiny amp is 440w.
That 440w could be rated at very high distortion levels. Car audio and home audio are rated very differently. You also have to take into consideration the impedance of the speakers, and their spl rating. You can take a 40 watt Punch amp and drive your eardrums mad with efficient speakers. You could also take a 1200 watt Bazooka PMiller amp and not move a JL Audio 13W7 in a sealed enclosure properly.
I've got 7 Polk Audio RTi speakers with a 4 ohm nominal impedance rating at 89dB for my home theater system, and struggle driving them with a $1200 Denon 3805 38lb surround receiver. Had I purchased Klipsch speakers, I could be driving them with a $199 Insignia (Best Buy) AVR at ear bleeding levels. Klipsch are very efficient speakers, but some equate them as fatiquing horn loaded towers.
Like the other posters stated, it's not about volume, but SQ (sound quality) at lower levels. I enjoy both loud, chest pounding rock, as well as Diana Krall at lower levels.
I am pulling my hair out trying to find a way to install a 10" or 12" sub in my '06 DC right now, and some where to mount a large monobloc amp. Four 8" woofers just doesn't cut it for me. There's just not enough room in these Toyota's compared to my F150. Music is my passion, so this will happen one way or another.
