Infinity INFDSP4425AM 4-Channel DSP Amplifier

The Infinity INFDSP4425AM is a compact 4-channel Class A/B car amplifier with integrated digital signal processing. It is designed for upgrading factory or aftermarket systems where speaker power, signal control, and tuning flexibility are needed in one chassis. Four powered channels and two full-range preamp outputs support a complete front/rear speaker upgrade and future system expansion.

This amplifier suits listeners and installers who want to improve the balance and integration of an existing car audio system without adding a separate DSP processor. Its 25 watts RMS per channel at 4 ohms is intended for efficient full-range speakers, while the DSP provides the adjustment tools needed to tailor the system to the vehicle. The result is a more controlled presentation with channel-by-channel setup capability.

Its onboard DSP is accessed through Infinity software on a Windows PC using the included USB tuning cable. The software provides crossover adjustment, time delay, channel gain, phase control, input mixing and summing, clipping indication, and selectable 31-band parametric or graphic EQ. Up to 10 tuning presets can be stored in the amplifier.

Balanced differential inputs help reject unwanted noise, and the amplifier accepts either RCA low-level or speaker-level input signals. This makes it practical for systems retaining a factory radio as well as installations using an aftermarket source unit. Selectable remote, audio-sense, and DC-offset turn-on modes add flexibility when connecting to different vehicle audio systems.

The INFDSP4425AM can also serve as the control center for a larger build. Its two full-range preamp outputs can feed a separate amplifier when more output power is needed later. An optional Infinity RBC wired remote can adjust the level assigned to channels 5 and 6 of the DSP preamp output section from the driver’s seat.

Key Features

• Four-Channel Class A/B Power: Delivers 25 watts RMS per channel at 4 ohms for full-range speaker systems.
• Integrated DSP: Provides crossover, EQ, time-delay, phase, gain, and mixer controls through Windows software.
• 31-Band EQ Modes: Choose parametric or graphic equalization for channel-specific sound tuning.
• Flexible Signal Inputs: Accepts RCA low-level and speaker-level source signals for broad system compatibility.
• Two Preamp Outputs: Sends a full-range signal to an additional amplifier for later system expansion.
• Selectable Turn-On Modes: Supports remote, audio-signal-sense, and DC-offset activation methods.

Design & Installation

The amplifier uses a compact curved-body design with angular end caps and Infinity branding. Its conformal-coated circuit board is intended to help protect the electronics in demanding mobile-audio environments. Red and green status indicators provide power and protection status at a glance.

Mount the amplifier where airflow is available and where wiring will not interfere with vehicle controls, fuel lines, brake lines, or factory harnesses. Use at least 8 AWG power and ground wire, a properly fused power connection, and the included harnesses for signal and speaker wiring. The four powered speaker channels cannot be bridged; use the RCA preamp outputs to add a separate amplifier when additional power is required.