Infinity Reference 3004A 4-Channel Car Amplifier

The Infinity Reference 3004A is a four-channel car amplifier designed to add dedicated power to front and rear speakers in an aftermarket or factory-integrated audio system. It delivers 75 watts RMS to each of four channels at 4 ohms, giving compatible speakers more headroom than a typical built-in radio amplifier. Its compact footprint helps make an amplified speaker upgrade practical where mounting space is limited.

This amplifier suits listeners building a clearer, more controlled full-range speaker system without replacing every source component at once. It accepts both low-level preamp signals and speaker-level signals, supporting use with many aftermarket receivers as well as factory radios. Separate front and rear input controls help match the amplifier to the source signal.

With 100 watts RMS per channel at 2 ohms, the Reference 3004A can support compatible low-impedance speaker loads. It can also operate in bridged two-channel mode, producing 200 watts RMS per channel into 4-ohm loads. This flexibility supports a staged system build, such as powering a pair of speakers or compatible subwoofers before expanding the system later.

Variable high-pass and low-pass filters are provided for both the front and rear channel pairs. The filters adjust from 32 to 320 Hz at a 12 dB-per-octave slope, allowing the amplifier to be configured for full-range speakers or appropriate low-frequency duties. Balanced differential inputs are designed to reduce noise and distortion and help resist radiated engine noise.

The Reference 3004A includes full-range preamp outputs for passing signal to an additional amplifier without using splitters. Selectable DC or remote turn-on operation provides options for high-level and low-level installations. Protection circuitry monitors for shorts, overheating, overvoltage, and undervoltage, with an LED indicator to show a protection condition.

Key Features

• Four-Channel Power: Delivers 75 watts RMS to each channel at 4 ohms.
• 2-Ohm Stable Operation: Provides 100 watts RMS per channel into compatible 2-ohm loads.
• Bridgeable Channels: Runs as two channels at 200 watts RMS each into 4 ohms.
• Variable Crossovers: Front and rear high-pass or low-pass filters support system tuning.
• Flexible Inputs: Accepts low-level preamp and speaker-level source signals.
• Protection Circuitry: Helps guard against shorts, heat, and voltage-related faults.

Design & Installation

The Reference 3004A uses a compact amplifier chassis measuring 12-5/8 inches wide, 2-3/16 inches high, and 7-1/8 inches deep. Its control layout includes separate front and rear gain and crossover adjustments, while the top panel can be removed to access controls. The design also includes power and protection status indication for system monitoring.

Use 8-gauge power and ground wiring as recommended by Infinity, and mount the amplifier where airflow is not blocked. Select low-level input operation with a receiver's RCA preamp outputs, or use the supplied bare-wire-to-RCA adapters for a speaker-level connection. Configure the front and rear filter modes and frequencies for the speakers or bridged 4-ohm loads being powered; power wiring and installation hardware are not included.