SIA-1250D

The SIA-1250D is a full-bridge mono amplifier that makes the same 1,250W RMS at 1 ohm and at 2 ohms, plus 800W RMS at 4 ohms. That flat output across two loads is the point: wire a dual 2-ohm subwoofer in series or parallel and you still get full rated power, so coil configuration stops dictating how much bass you end up with.

Thermal management comes from a heavy heatsink paired with a three-speed Smart Cooling fan that steps up only as temperature climbs, staying quiet during casual listening and moving real air when the amp is working hard. The intelligent full-bridge design and power supply layout keep output clean instead of letting the amp clip its way through a long session.

Onboard tuning includes a variable 12dB low pass filter from 40Hz to 20kHz, a variable 12dB high pass filter from 10Hz to 1kHz, a subsonic filter that keeps the woofer from wasting travel below box tuning, and a variable 12dB bass boost at 50Hz. Input sensitivity is 5V max, signal-to-noise ratio is 108dB, and operating voltage spans 10.5V to 15.5V DC. Recommended fuse rating is 120A.

Power, protection, and clipping indicators show status at a glance, and protection circuitry monitors thermal load, voltage, speaker shorts, and DC offset. At 7.25" x 7.25" x 2.45" it fits a trunk rack, a rear-seat wall, or a false floor, and the included wired remote keeps bass level adjustable from the seat.