Kenwood KAC-D8105 5-Channel Class D Car Amplifier

The Kenwood KAC-D8105 is a five-channel Class D car amplifier designed to run four full-range speakers and a dedicated subwoofer from one compact chassis. It provides a practical upgrade path for vehicles where factory amplification is limited or where separate amplifiers would take up too much space. With dedicated A/B and subwoofer channel sections, it supports a complete speaker-and-subwoofer system from a single amplifier.

At 4 ohms, the KAC-D8105 is rated for 50 watts RMS across each of four A/B channels plus 300 watts RMS for the subwoofer channel. At 2 ohms, its ratings increase to 75 watts RMS x 4 and 500 watts RMS x 1. This makes it suitable for systems that need clean power for front and rear speakers while retaining a separate low-frequency channel for a compatible subwoofer.

The A/B channels have a 20 Hz to 50 kHz frequency response, while the subwoofer channel is specified from 20 Hz to 200 Hz. Variable high-pass and low-pass filters help divide frequencies between speakers and subwoofer for a more purposeful system setup. A variable subwoofer bass boost control is also provided for low-frequency adjustment at 40 Hz.

Kenwood equips the KAC-D8105 with Dual Sigma Drive negative-feedback technology, which is intended to improve damping and control speaker movement. Its Power MOS-FET switching power supply supports the amplifier's efficient Class D design. Independent gain adjustment for the A/B and subwoofer sections allows installers to set levels for the full-range and bass portions of the system separately.

The amplifier accepts both RCA and speaker-level input signals, making it useful with aftermarket receivers as well as many factory-radio installations. Signal-sensing turn-on can activate the amplifier from a speaker-level input signal when applicable. Its compact 9-inch-wide chassis is designed for installations where space is limited, including many under-seat or trunk locations.

Key Features

• Five-Channel Configuration: Powers four speakers plus one dedicated subwoofer channel from one amplifier.
• 1600W Maximum Power: Provides the manufacturer's stated maximum-power rating for the complete amplifier.
• 2-Ohm Load Capability: Supports rated operation with compatible 2-ohm speaker loads.
• Variable Crossovers: High-pass and low-pass filters help direct frequencies to appropriate speakers.
• Speaker-Level Inputs: Supports connection to compatible factory-radio speaker outputs.
• Signal-Sensing Turn-On: Can detect an incoming speaker-level signal for activation.

Design & Installation

The KAC-D8105 uses an extruded aluminum heat-sink design and a compact Class D layout. Its power and ground connections use M6 screw-type terminal blocks, while the speaker outputs use M4 screw-type terminal blocks. The chassis measures 9 inches wide by 2-3/16 inches high by 7-3/8 inches deep and weighs 4.5 pounds.

Plan the installation around the amplifier's dimensions, ventilation needs, and the vehicle's 11 to 16 volt operating range. Connect a source through RCA line inputs or the speaker-level input, then set the A/B high-pass and subwoofer low-pass controls to suit the speakers and subwoofer being used. Match loads carefully: the bridged A/B outputs require a 4- to 8-ohm load, while the amplifier is rated for 2- to 8-ohm allowable speaker loads.