Hifonics ZD-1350.4D 4-Channel Class D Car Amplifier

The Hifonics ZD-1350.4D is a compact four-channel Class D mobile amplifier designed to add external amplification to a vehicle audio system. It can be used to power front and rear speakers independently or configured for two bridged channels with compatible 4-ohm loads. Its full-range design makes it a practical option for multi-speaker upgrades where an aftermarket or factory source unit needs more output capability.

This amplifier is intended for listeners building a clearer, more controlled speaker system without using a large chassis amplifier. It provides manufacturer-rated output of 170 watts per channel at 4 ohms or 335 watts per channel at 2 ohms. For bridged applications, it is rated for 675 watts per channel across two channels at 4 ohms.

Adjustable high-pass and low-pass crossovers allow the ZD-1350.4D to be matched to the role of the speakers it powers. The crossover ranges from 50 Hz to 250 Hz with a 12 dB-per-octave slope, helping separate bass and higher-frequency duties in a system. A built-in bass control is also provided for output adjustment.

The amplifier uses a PWM MOSFET power supply with a Simpatico coil design to maintain operating voltage through the output stage. Its Class D topology and aluminum heat sink support efficient operation in a compact enclosure. A low-noise preamplifier circuit is designed to accept low-level source signals with minimal distortion.

For installation flexibility, the ZD-1350.4D supports four-channel, full-range, and bridged operation modes. DC Signal Sense can turn the amplifier on when a signal is received at the RCA inputs, eliminating the need for a remote turn-on wire when that setup is appropriate. LED diagnostics provide illuminated indication for overload and speaker-short protection conditions.

Key Features

• Four-Channel Class D Design: Powers four speakers independently or supports two bridged channels.
• 2-Ohm Stable Operation: Delivers up to 335 watts per channel at 2 ohms.
• Variable Electronic Crossovers: Helps tailor frequency ranges for speakers or subwoofer applications.
• DC Signal Sense: Can activate the amplifier from a detected RCA input signal.
• PWM MOSFET Power Supply: Supports stable power delivery through the amplifier circuitry.
• LED Protection Diagnostics: Provides visible overload and speaker-short status indication.

Design & Installation

The ZD-1350.4D has a black compact chassis with an aluminum heat sink for heat dissipation. Its RCA inputs are nickel-plated and specified as high-temperature, impact-resistant, and erosion-resistant. Secure molded terminals are angled for access and organized power, ground, and speaker wiring.

Use 4 AWG cable at the power and ground terminals, a properly fused direct battery connection, and a secure bare-metal chassis ground. The amplifier uses an external 60A fuse and accepts up to 12 AWG speaker wire at its speaker terminals. Select four 2-ohm-or-higher speaker loads for individual channels, or use 4-ohm loads when bridging channels; install in a secure location with adequate ventilation.