Kenwood eXcelon X303-4 4-Channel Class D Car Amplifier

Four channels of clean power

The X303-4 is a 4-channel Class D amplifier from the Kenwood eXcelon line. Kenwood rates it at 50 watts x 4 RMS at 4 ohms, 75 watts x 4 at 2 ohms, or 150 watts x 2 bridged at 4 ohms, with 600 watts maximum. Its CTA-2006-D rating is 50 watts x 4 at 4 ohms and 1% THD or less, with an 84 dBA signal-to-noise figure. Frequency response reaches 20 Hz to 50 kHz, and the amp is certified to the Hi-Res Audio standard.

Flexible crossover controls

Channels A and B each have a filter switch with high-pass, off and low-pass positions, and a frequency control from 50 to 200 Hz at 12 dB per octave. That lets one pair run full-range or high-passed speakers while the other drives a bridged subwoofer. Channel B adds a bass boost of 0 to 18 dB at 40 Hz. Input sensitivity adjusts from 0.2 to 5.0 volts for RCA inputs and 4 to 12 volts for speaker-level inputs.

Built for easy installs

All power, speaker and input connections sit on one side for tidy wiring. The included speaker-level input harness and signal-sensing turn-on let the amp work with a factory radio that has no RCA outputs. Set-screw terminals take 4 to 6 gauge power wire and 8 to 16 gauge speaker wire, two 20 A fuses protect the circuit, and a resin terminal cover is fitted. The output coil has a magnetic shield and PMLCAP capacitors are used in the filter circuit. The amp measures 8-3/8 x 2-1/16 x 5-7/8 inches and weighs 3.1 pounds.

• eXcelon Class D 4-channel amplifier for front and rear speakers
• Rated 50 watts x 4 RMS at 4 ohms and 75 watts x 4 at 2 ohms
• Bridgeable to 150 watts x 2 RMS at 4 ohms for a subwoofer or larger speakers
• CTA-2006-D compliant: 50 watts x 4 at 4 ohms and 1% THD or less, 84 dBA
• Hi-Res Audio certified with a 20 Hz to 50 kHz frequency response
• High-pass, off or low-pass filter on channels A and B, 50-200 Hz at 12 dB per octave
• Bass boost on channel B adds 0 to 18 dB at 40 Hz
• Speaker-level input harness and signal-sensing turn-on included for factory radio upgrades
• One-side connections with set-screw terminals and two 20 A fuses

• Power and ground wiring, an inline fuse, RCA cables and speaker wire are not included.
• The amplifier draws up to 19 A; use 4 to 6 gauge power wire as Kenwood specifies.
• Speaker impedance is 4 ohms (2 to 8 ohms allowable); bridged loads must be 4 to 8 ohms.
• No wired remote level control is supplied with this model.

• Kenwood eXcelon X303-4 amplifier
• Speaker level input cable
• Self-tapping screws 4 x 16 mm (4)
• Hexagon wrench 2.5 mm
• Hexagon wrench 4.0 mm

• Kenwood X303-4 instruction manual (PDF, English/French/Spanish; shared with X3001-4 and KAC-334)