DC Audio 90.4 4-Channel Amplifier

DC Audio 90.4 4-Channel Amplifier is a 4-channel Class A/B amp with a fully active crossover, engineered for SQ-focused builds that demand precise frequency control and clean power across channels. It provides 90 W RMS per channel at 4 ohms, 130 W per channel at 2 ohms, and 250 W per bridged pair at 4 ohms (500 W total).

Fully Active Crossover : Each channel has independent filtering, letting you tailor front-stage and subwoofer integration for tighter imaging and cleaner bass.

Variable High Pass Filter : Adjustable high-pass to keep mid/treble drivers from shoulders of bass, reducing distortion and voice-coil stress in the lows.

Variable Band Pass Filter : Enables precise midbass/midrange shaping to tighten vocal presence and instrument clarity within a defined frequency band.

8 AWG Speaker Connections : Heavy-gauge wiring support ensures low-impedance paths and consistent current delivery to speakers.

4 AWG Power / Ground inputs : Robust power and ground connections for stable performance under dynamic musical transients.

Input Mode Switch : Flexible setup options to accommodate different source configurations.

Class A/B : Proven efficiency and dynamics suitable for high-fidelity car audio systems.

Remote Control : Optional remote control capability for convenient sub level adjustments (where supported).

Subsonic Filter (CH1/2) : 10 Hz–100 Hz to protect speakers and minimize cone movement on ultra-low bass.

Subsonic Filter (CH3/4) : 10 Hz–100 Hz for additional channel pair bass control.

Crossover Range : 50 Hz (500 Hz) ~ 500 Hz (5 kHz) with selectable stages for tailored limiting.

Multiply : x1, x10 options for crossover calibration precision.

Crossover Selector Switch : HPF / FULL / LP-BP to match each channel’s role in the system.

Bass Boost : 0–18 dB to add tactile warmth at the listening position without saturating the sub.

Frequency Response : 20 Hz–20 kHz for full-range musical fidelity.

Signal to Noise Ratio : 105 dB for low-noise performance in active systems.

Damping Factor : 200

THD @ 4 ohms : < 0.1%

• : On board 80 amp protection

LED Status Lights : Power and Protect indicators for quick health checks.

Heatsink : HD heatsink with dimensions 14.00" (350 mm) length, 9.38" (238 mm) width, 2.35" (59.6 mm) height for solid thermal performance.

Benefits: This amplifier shines in SQ builds that drive a front stage while optionally bridging the rear channels to a sub. The fully active crossover and per-channel filter options provide precise tonal shaping, while the high-current 4/8 AWG connections and rugged heatsink ensure stable, clean power under dynamic music. With a 105 dB SNR, less than 0.1% THD at 4 ohms, and generous headroom across 4–2 ohm loads, it is well suited to systems seeking high-fidelity bass extension and articulate imaging without compromise.