Hifonics ZD-2550.1D Compact Mono Class D Amplifier

The Hifonics ZD-2550.1D is a compact mono Class D mobile amplifier designed for subwoofer-focused car audio systems. It concentrates its output into one channel, making it suited to powering a properly matched subwoofer system rather than a full-range speaker array. Its adjustable low-pass crossover, subsonic filter, and bass controls help tailor bass output to the vehicle and enclosure.

This amplifier is intended for listeners building or upgrading a dedicated low-frequency section in a universal-fit vehicle audio system. It offers manufacturer-listed output ratings at 1, 2, and 4 ohms, allowing installers to select a compatible subwoofer wiring configuration. The mono-only layout keeps the setup focused on bass reproduction and simplified subwoofer amplification.

A PWM MOSFET power supply and Class D topology support high-output operation in a compact chassis. Hifonics also specifies a Simpatico dual-coil pulse-width-modulated power-supply design intended to help maintain voltage through the output devices. The aluminum heat sink is designed to assist with heat dissipation during operation.

Signal and tuning connections are arranged for practical installation, with nickel-plated RCA inputs and molded, angled power, ground, and speaker terminals. The amplifier accepts speaker-level audio inputs as well as RCA signal input. A built-in bass control and wired bass remote provide convenient adjustment of low-frequency output.

For systems without a conventional amplifier remote lead, DC Signal Sense can switch the amplifier on when it detects a signal at the RCA inputs. Illuminated diagnostic indicators monitor overload and speaker-short protection conditions. With its compact item dimensions, the ZD-2550.1D can fit installations where dedicated subwoofer amplification is needed without using a large amplifier footprint.

Key Features

• Mono Class D Design: Delivers a single amplified channel for subwoofer-oriented systems.
• 2550-Watt Maximum Rating: Manufacturer-listed maximum output is 2550 watts at 1 ohm.
• Variable Low-Pass Filter: Adjusts the low-pass crossover from 50Hz to 250Hz.
• Subsonic Filter: Adjustable 15Hz to 40Hz filtering supports enclosure-specific tuning.
• DC Signal Sense: Can turn on from an RCA input signal.
• Wired Bass Remote: Included remote provides convenient bass-level adjustment.

Design & Installation

The ZD-2550.1D uses an aluminum heat sink, a black finish, nickel-plated RCA inputs, and high-temperature impact-resistant connection hardware. Its power, ground, and speaker terminals are housed in a molded, angled terminal arrangement to support organized wiring access. LED diagnostic circuitry provides illuminated indication for overload and speaker-short protection.

Match the connected subwoofer load to one of the amplifier's listed 1-, 2-, or 4-ohm output ratings, and use the onboard low-pass, subsonic, gain, and bass-boost adjustments during setup. The amplifier uses 4 AWG 12V and ground terminals, 12 AWG speaker terminals, and an external 125A fuse specification. It can be installed using RCA or speaker-level audio inputs; DC Signal Sense is available when using RCA signal input.