Description
JL Audio AP300/4 – 4-Channel Class-D Marine Amplifier
The JL Audio AP300/4 is a compact 4-channel Class-D amplifier from the AP marine series, designed to deliver up to 300 watts of clean, efficient power in a small, IP67-rated chassis. It can drive multiple pairs of full-range speakers or a mix of speakers and a subwoofer using its flexible bridging and onboard crossovers, making it ideal for small to mid-size boats and powersports builds where space and reliability are critical.
Compact Class-D Power for Multiple Zones
As the 4-channel model in the AP lineup, the AP300/4 is engineered to power up to four pairs of speakers or a combination of two pairs of speakers and a subwoofer using bridged channels. Its efficient Class-D topology delivers strong output while minimizing battery drain, a key advantage on marine and powersports electrical systems.
At 14.4 V and less than 1% THD, the AP300/4 is rated for 50 watts x 4 into 4 ohms or 75 watts x 4 into 2 ohms. For higher-output configurations, channels can be bridged to provide 150 watts x 2 into 4 ohms, giving you flexibility in how you allocate power between full-range zones and low-frequency channels.
- 4-channel Class-D amplifier designed for full-range or mixed speaker/subwoofer systems.
- Rated continuous power of 50 W x 4 @ 4 Ω or 75 W x 4 @ 2 Ω (14.4 V, <1% THD).
- Bridged output capability of 150 W x 2 @ 4 Ω for higher-output speaker or subwoofer channels.
- Full-range frequency response from 20 Hz–20 kHz (+0, -1 dB) for clear, wide-band audio.
- Signal-to-noise ratio >70 dB (A-weighted, 20 Hz–20 kHz, referred to 1 W) for low-noise performance.
LCD On-Amp Control, Easy Tune & Marine Durability
A built-in LCD display gives you direct access to key amplifier settings at the amp itself, simplifying setup and adjustments during installation or service. For further optimization, the AP300/4 supports JL Audio’s Easy Tune feature when paired with a compatible Fusion® stereo that has built-in DSP and the Fusion® Audio app, allowing quick, profile-based setup to help protect speakers and maintain consistent system tuning.
Designed for harsh marine environments, the amplifier chassis carries an IP67 water and dust rating (excluding cables) and is ignition protected. Its compact footprint and low idle current draw make it easy to mount and integrate in tight compartments without putting unnecessary strain on the battery system.
- Built-in LCD display for manual control and amplifier setup right on the unit.
- Easy Tune feature supported when used with Fusion® stereos with DSP and Fusion® Audio app.
- IP67-rated amplifier chassis (excluding cables) for water and dust resistance.
- Ignition protected design for use in appropriate marine engine compartments.
- Physical dimensions: 1.86" (H) x 10.43" (W) x 4.90" (D) / 47 x 265 x 125 mm.
| Part Number | 010-03429-00 (AP300/4, 4-channel model) |
| Channels | 4-channel |
| Amplifier Class | Class D |
| Operating Voltage | 9–16 VDC |
| Water/Dust Rating | IP67 (amplifier chassis, excluding cables) |
| Operating Temperature | 4° to 149°F (-20° to 65°C) |
| Rated Power @ 4 Ω (14.4 V) | 50 W x 4 / 150 W x 2 bridged (<1% THD) |
| Rated Power @ 2 Ω (14.4 V) | 75 W x 4 (<1% THD) |
| Frequency Response | 20 Hz – 20 kHz (+0, -1 dB) |
| Signal-to-Noise Ratio | >70 dB (A-weighted, 20 Hz–20 kHz, referred to 1 W) |
| Standby Current | <1 mA |
| Idle Current | Approximately 700–750 mA |
| Fuse Rating | 35 A (AFS, AGU, or MaxiFuse™ recommended) |
| Minimum Power/Ground Wire | 4 AWG copper wire |
| Protection Circuits | Input under/over voltage, over-temperature, output short circuit |
| Amplifier Dimensions (H x W x D) | 1.86" x 10.43" x 4.90" (47 x 265 x 125 mm) |
| Warranty | 3 years |
| High-Pass / Low-Pass Filters | Yes – full-range filters, user selectable |
| Filter Modes – Channels 1 & 2 | Off, High-pass (HP) or Low-pass (LP) |
| Filter Modes – Channels 3 & 4 | Off, High-pass (HP) or Low-pass (LP) |
| Filter Slope | 12 dB/octave (all channels) |
| Filter Frequency Range | 20 Hz – 500 Hz (HP or LP, channels 1–4) |
| HP Variable Crossover | Yes – 4-channel, 12 dB/octave |
| LP Variable Crossover | Yes – 4-channel, 20–500 Hz |
| Bass Boost EQ | 0 to +18 dB @ 37 Hz |
| Input Sensitivity | RCA inputs switchable: 200 mV–2 V RMS (Low), 800 mV–8 V RMS (High) |
| Input Impedance | 11 kΩ (High), 20 kΩ (Low) |
- JL Audio AP300/4 4-channel marine amplifier
- Four amplifier mounting screws
- Documentation and installation information
Used Frequently Asked Questions
- What does used mean? Used products may be unused customer returns that are essentially "new" items, or they may be previously installed products that were returned under warranty or during our return policy period.
- What is the warranty? All of our used items come with a 90-day warranty.
- What's it look like? All of our used items are inspected and graded by our returns team at our facilities. They will test them and grade them to one of four standard gradings: Used Open Box, Used Very Good, Used Good, and Used Acceptable. Please see the following descriptions of each grade - also note that if an item falls under ANY of the criteria for a certain grade, even though the rest of the product is better, we will give it the lowest grade.
- Used Open Box An item in perfect working condition. Original protective wrapping may be missing, but the original packaging is intact and in good condition with minor damage possible. Instructions are included.
- Used Very Good A well-cared-for item with limited use, remains in good working condition. The item may show some limited signs of wear,small scratches,cosmetic blemishes. Item may arrive with damaged packaging or be repackaged and could be missing some accessories.
- Used Good The item shows wear from use, remains in good condition and functions properly. May have damaged packaging or be repackaged. It may be marked, have identifying markings on it, have minor cosmetic damage. It may be missing some parts or accessories.
- Used Acceptable The item is fairly worn but continues to function properly. While repackaged; signs of wear can include aesthetic issues; scratches, dents. The item may have markings on it or show signs of previous use. Item may be missing some parts or accessories.
- Have more questions? Call us, send us a chat, or an email. We'll be able to answer any additional questions you may have.