Here's my car, 97 White Honda Civic EX Coupe.

Audio system:
Alpine CTA-1505 HU
Alpine CHA-S604 Changer
Alpine MRV-F407 4-channel amp
Alpine MRV-T757 2-channel amp
JL Audio XR650-CSi 6.5" comp set
JL Audio 10W7-3 10" subwoofer
1.7cf sealed enclosure
Monster wiring, distribution

From the front, I have an Alpine "System Commander" (CTA-1505). Basically it is a tuner, receiver (26x4 RMS .8% THD @ 14.4V, pretty high power for a deck in those days) and changer controller (no internal CD player). Also has some processing features. BBE, 7-band EQ, spectrum analyzer. And RDS.

Signal originates at an Alpine 6-disc changer (CHA-S604) and then to the commander.

A Low-level, full-range signal goes to an Alpine 4-channel amplifier (MRV-F407). The amp is rated for 40W/channel @ 12V, was specified at 60W/channel @ 12V. I should be running somewhere in the vicinity of 60~90x4 (120~180W/side) depending on operating voltage.

The amplifier power a JL Audio 6.5" component set (XR650-CSi).

Channels 1 & 2 are sent full-range to the high inputs of the JL XR passive Xovers (XR650/570-CSpxo). The signal is then hi-passed for tweeter duty and attenuated (currently -1.5dB). JL XR tweeters (XR100-CT) are installed in the sail panels of each door.

Channels 3 & 4 are sent high-passed (60Hz or so) to the low inputs of the Xovers. The signal is then low-passed for midbass duty at 2~3kHz. JL XR 6.5" mid woofers (XR650-CW) are installed in the lower front of each door.

The sub-out of the CTA-1505 goes to an Alpine 2-channel amplifier (MRV-T757). This amp is rated at 75W/channel @ 12V, specified at 109W/channel @ 12V. I should be running somewhere around 450~600W (bridged) to the sub depending on operating voltage.

The sub signal is low-passed around 60Hz (24dB/octave) to a single JL Audio 10" subwoofer (10W7-3) in a 1.7cf sealed enclosure. The enclosure has a removable vent plug that tunes the enclosure at 32Hz for extra output if necessary.

Trunk images. (10W7 in enclosure, Alpine amps, JL XR Xovers)

Odds & ends:
JL XR650-CW midbass vs JL 6W0 subwoofer.

JL 6W0 @ full excursion. I plan to have a pair for up front bass to play between midbass and sub.

10W7 enclosure design & 3D model.

My trunk w/Brahma 12.

Other Brahma images.

12A prototype version images.

12A production version images.

Comparison images:
(clockwise from upper left - 10W7, 12W3, Solo 12, 12A proto)

Justin's graphics work: