Pioneer GM-DX971 Class D Mono Subwoofer Amplifier

The Pioneer GM-DX971 is a mono Class D amplifier designed to add dedicated subwoofer power to a car audio system. It is built for systems that need stronger low-frequency output than a receiver or full-range amplifier can provide alone. With a stable operating range down to 1 ohm, it offers multiple wiring and power-matching options for compatible subwoofers.

This amplifier is intended for listeners building a focused bass section in a factory or aftermarket audio system. Its output is rated at 500 watts RMS at 4 ohms, 800 watts RMS at 2 ohms, and 1,200 watts RMS at 1 ohm. A variable low-pass filter helps keep upper frequencies out of the subwoofer channel for a more controlled bass blend.

Class D amplification helps the GM-DX971 deliver substantial subwoofer power from a compact chassis. The amplifier covers a 10 Hz to 240 Hz frequency response and includes a 50 Hz bass-boost circuit adjustable from 0 dB to 18 dB. A wired bass remote lets the driver adjust bass boost level from an accessible location.

The GM-DX971 supports both RCA-level and speaker-level signal connections. Its supplied speaker input wire with RCA pin cord can connect to speaker outputs from a factory radio, and the amplifier can automatically turn on from speaker-level signal with compatible head units. Gold-plated RCA terminals and a high-current circuit design support reliable signal and power connections.

For a complete bass upgrade, pair the GM-DX971 with subwoofer wiring that produces a final load between 1 and 8 ohms. Pioneer specifies suitable subwoofer nominal-power minimums of 500 watts at 4 ohms, 800 watts at 2 ohms, or 1,200 watts at 1 ohm. Built-in protection monitors abnormal operating conditions, while the compact dimensions help fit the amplifier in a range of vehicle installations.

Key Features

• 1-Channel Class D Design: Delivers dedicated mono amplification for a subwoofer system in a compact format.
• 1,200W RMS at 1 Ohm: Provides its highest continuous output into a properly wired 1-ohm load.
• Variable Low-Pass Filter: Adjusts the subwoofer cutoff point from 40 Hz to 240 Hz.
• Wired Bass Remote: Lets you adjust 50 Hz bass boost from the driver’s seat.
• RCA and Speaker-Level Inputs: Works with aftermarket receivers and many factory-radio installations.
• Protection Circuitry: Helps protect the amplifier during overheating, DC output, and speaker-wire shorts.

Design & Installation

The GM-DX971 uses a compact 11-7/8-inch-wide chassis with a heat-dissipation-focused structure and Pioneer Total Vibration Control design. Gold-plated RCA terminals are used for the signal connections, and the amplifier includes a POWER/PROTECT status indicator. Three 40-amp onboard fuses are installed in the amplifier.

Mount the amplifier on a flat, rigid surface with open space above it for ventilation; do not cover it with carpet or a floor mat. The manual specifies a separately sold 150-amp battery-line fuse and equal-size battery and ground wiring, with 6 AWG recommended below 11 ft. 10 in. and 4 AWG below 20 ft. 12 in. Set gain and low-pass filtering to match the source unit and subwoofer system, and keep the final speaker load between 1 and 8 ohms.