Infinity Primus 9004A Car Audio Amplifier – SoundHub

Infinity Primus 9004A Car Audio Amplifier

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  • Regular price $299.00
Tax included.

Value Engineered

Primus amplifier provides true Infinity performance at an affordable price while now lacking the features needed to properly tune and optimize performance.

Compact footprint

With it becoming more and more difficult to find spacious locations for amplifier mounting, Primus has been developed in a small compact form factor to allow more location versatility. 

Full On-Board Protection

Primus amplifier has on-board circuitry to protect them from shorts, temperature, overvoltage and undervoltage. An LED indicator is included on all four models to let you know when one of these conditions exists. 


Infinity is one of the best selling car audio brands in the world. This is not a coincidence given the arduous testing and quality control. We take our craft seriously and want every consumer to have a world-class experience that lasts and lasts. 

Input Sensitivity

An input level control adjusts input sensitivity. When low level inputs are used, this control can adjust the input between 200mVrms and 5.0Vrms. When high level inputs are used, the control adjusts the input between 0.5Vrms and 15Vrms. This allows Primus amps to be connected to virtually any factory system or serve as the foundation for a trophy-winning aftermarket competition system. 

Switchable bass EQ

This provides an available bass boost at 45Hz of 6dB or 12dB, serving as a great tool to optimize subwoofer and loudspeaker performance based on location and enclosure type.

Crossover mode switch

LPF crossover controls are switchable between 0dB to 12dB at 45Hz giving user ability to adjust the sound to the environment and/or application. 

Crossover control gives user additional fine tuning

Adjusts the crossover turnover frequency between 32Hz and 320Hz. (One knob for each stereo pair.)

General Specifications

Primus 9004a Operating voltage 9 – 16V

RMS power @ 4 ohms 90W

RMS power @ 2 ohms 110W

RMS bridged power @ 4 ohms 220W

Total peak power 880W

Frequency response 20Hz – 20kHz @ -1dB THD + N at rated power (20Hz – 20kHz) <1% Line-in signal-to-noise ratio (reference to 1 watt) >75dB