Infinity PRIMUS3000A Mono Subwoofer Amplifier

The Infinity PRIMUS3000A is a compact mono car amplifier designed to add dedicated power for a subwoofer system. It delivers up to 300 watts RMS through its single channel into a 2-ohm load. This makes it a practical choice for drivers who want stronger low-frequency output without replacing the entire audio system.

This amplifier is intended for use with a single subwoofer or a compatible pair of subwoofers wired to a final impedance of 2 ohms or higher. Its low-pass crossover keeps higher frequencies out of the subwoofer signal, helping the bass system blend more naturally with full-range speakers. A variable phase control can also help optimize bass response relative to the front speakers.

The PRIMUS3000A supports both RCA line-level and speaker-level signal connections. That flexibility allows it to work with many aftermarket receivers as well as factory audio systems that do not provide dedicated preamp outputs. Its adjustable input sensitivity helps match the amplifier to the signal level supplied by the source unit.

For system tuning, the amplifier includes a variable low-pass filter from 32 to 320 Hz and a bass EQ adjustable from 0 to 12 dB. The bass EQ center frequency is adjustable from 40 to 100 Hz, allowing the boost range to be tailored to the subwoofer enclosure and vehicle acoustics. A variable 0 to 180-degree phase control provides another way to refine bass integration.

The PRIMUS3000A includes built-in protection for DC, over-voltage, under-voltage, over-current, and overheating conditions. Its power/protect indicator shows blue during normal operation and red when protection is active. The amplifier can serve as a focused bass upgrade in a factory-radio system or as the subwoofer channel in a larger aftermarket build.

Key Features

• Mono Subwoofer Channel: Supplies dedicated amplification for a compatible subwoofer system.
• 300W RMS at 2 Ohms: Provides continuous power for low-frequency reproduction.
• Variable Low-Pass Filter: Adjusts the subwoofer crossover point from 32 to 320 Hz.
• Adjustable Bass EQ: Adds 0 to 12 dB of bass emphasis.
• RCA and High-Level Inputs: Supports aftermarket and many factory audio sources.
• Protection Circuitry: Helps guard against electrical faults and excessive temperature.

Design & Installation

The PRIMUS3000A uses a compact black amplifier chassis with a grooved center panel, polished Infinity badge, and black-painted end panels and bottom. End-panel controls and connections place the gain, crossover, bass EQ, phase adjustment, power terminals, speaker terminals, RCA inputs, and high-level input connection within reach during setup. A blue/red power-protect indicator provides visible operating-status feedback.

Mount the amplifier in a dry location with adequate airflow, such as a trunk or under-seat area, and do not install it with the heat sink facing downward. Infinity specifies a minimum 8-gauge power and ground connection, plus an inline 30A fuse within 18 inches of the battery for the PRIMUS3000A. Connect the subwoofer at a final load of 2 ohms or higher, then set gain, low-pass frequency, bass EQ, and phase to suit the vehicle and speaker system.