JBL Marine A1504 4-Channel Marine Amplifier

The JBL Marine A1504 is a four-channel marine amplifier designed to add substantial, controlled power to a boat audio system. It can drive four full-range speakers from one compact chassis, making it a practical upgrade when a marine receiver alone does not provide enough output. Its Class D design is intended to provide high output while managing current draw.

This amplifier is suited to boat owners building a louder multi-speaker system or upgrading existing marine speakers with dedicated amplification. It delivers 150 watts RMS to each of four channels at 4 ohms, with higher output available when using 2-ohm speaker loads. For systems that include subwoofers, the amplifier can also be configured in bridged two-channel or three-channel arrangements.

Variable high-pass and low-pass crossovers on the front and rear channels help tailor the signal for the speakers being used. Each crossover section adjusts from 32 to 320 Hz with a 12 dB-per-octave slope, allowing full-range speakers to be high-passed or bridged channels to be low-passed for subwoofer duty. Full-range operation is also available when no crossover is needed.

The A1504 supports both low-level preamp inputs and speaker-level inputs, helping it work with aftermarket marine receivers as well as many factory systems. Its selectable turn-on mode supports remote turn-on with low-level inputs or DC-sensing operation with high-level inputs. Balanced differential inputs are designed to reduce susceptibility to induced engine noise.

Marine-oriented construction includes a conformal-coated circuit board and corrosion-resistant stainless-steel connections. Built-in protection circuitry monitors for short circuits, high temperature, overvoltage, and undervoltage conditions, with a power/protection indicator for status. Full-range preamp outputs also allow a second amplifier to be added without relying on signal splitters.

Key Features

• Four-Channel Class D Power: Supplies 150 watts RMS to each channel at 4 ohms.
• Flexible Bridging: Provides up to 450 watts RMS per bridged channel pair at 4 ohms.
• Variable Crossovers: Front and rear high-pass or low-pass filters support system tuning.
• High- And Low-Level Inputs: Works with RCA preamp outputs or speaker-level signals.
• Marine-Focused Construction: Uses a conformal-coated board and corrosion-resistant connections.
• System Expansion: Full-range preamp outputs can feed an additional amplifier.

Design & Installation

The A1504 uses a low-profile chassis measuring 14-3/16 inches wide, 2-1/16 inches high, and 7-1/8 inches deep. Its Class D platform, conformal-coated circuit board, and corrosion-resistant stainless-steel connections are intended for the environmental demands of marine installations. On-board protection covers short circuits, overheating, overvoltage, and undervoltage conditions.

JBL recommends 4-gauge power and ground wiring; the amplifier wiring and hardware are not included. Make all wire connections before final mounting, use a location with adequate airflow, and do not mount the heat sink facing downward. The box includes high-level bare-wire-to-RCA adapters, fuses, mounting screws, an owner’s manual, JBL stickers, and a logo badge.