The build

Vehicle

Second-generation Scion xB

Subwoofers

Six DS18 15-inch subwoofers

Enclosure

Fourth-order, behind a B-pillar wall

Amplifiers

Three DS18 HKO-8K

Peak power

7,553 W at 1.4 ohms (on-board meter)

Best score

160.59 dB at 33 Hz

Goal

Maximum SPL (sound pressure level)

The amp wall

The wall has also run in black with a lime green base:

How it is laid out

The cargo area is sealed off behind a wall at the B-pillar, the post behind the front doors. The six DS18 15-inch subwoofers fire into a fourth-order (bandpass) enclosure, where the woofers sit in a sealed chamber and play through a ported one. A fourth-order box trades bandwidth for output in a narrow range, which is what an SPL competition rewards.

Three DS18 HKO-8K amplifiers drive the subwoofers. They hang on a plywood amp wall in the rear hatch, with the power cabling run in green loom along the edges and a battery bank under the shelf.

Power

A watt meter on the wall records the peak the amplifiers deliver. Its best reading: 7,553 watts into a 1.4 ohm load.

From the inside

Results