Description
JL Audio AP300/1 – 300-Watt Class-D Marine Monoblock Subwoofer Amplifier
The JL Audio AP300/1 is a compact Class-D monoblock amplifier from the AP marine series, purpose-built to power a dedicated subwoofer channel in boats and powersports systems. It delivers up to 350 watts of continuous power at 2 ohms from a small, IP67-rated, ignition-protected chassis that is designed to survive in harsh marine environments.
Dedicated Subwoofer Power in a Compact Chassis
As the monoblock model in the AP lineup, the AP300/1 is optimized to drive a single subwoofer or subwoofer array with stable Class-D power and sub-bass-focused signal processing. It is designed to run from a 9–16 VDC marine electrical system, providing strong output with lower battery drain than traditional Class-AB amplifiers.
At 14.4 V and less than 1% THD, the AP300/1 is rated for 200 watts x 1 into 4 ohms and 350 watts x 1 into 2 ohms. Its 10 Hz–500 Hz bandwidth is tailored for subwoofer duty, with onboard crossovers and filters aimed at low-frequency control and driver protection.
- Monoblock Class-D design specifically engineered for powering a subwoofer channel.
- 200 W x 1 @ 4 Ω and 350 W x 1 @ 2 Ω (14.4 V, <1% THD) for strong, controlled bass output.
- Subwoofer-focused frequency response from 10 Hz–500 Hz (+0, -1 dB).
- Signal-to-noise ratio >70 dB (A-weighted, 20 Hz–20 kHz, referred to 1 W) to help keep system noise low.
- Compact footprint: 1.86" (H) x 10.43" (W) x 4.90" (D) / 47 x 265 x 125 mm.
On-Amp Control, Easy Tune & Marine Durability
A built-in LCD display on the amplifier provides direct access to key settings, simplifying setup and fine-tuning without needing external tools. For further optimization, the AP300/1 supports JL Audio’s Easy Tune feature when paired with a compatible Fusion® stereo with built-in DSP and the Fusion® Audio app, enabling profile-based configuration focused on sound quality and system protection.
The amplifier chassis is built to IP67 water and dust standards (excluding cables) and is ignition protected, making it suitable for demanding marine environments and appropriate engine compartment installations. Its compact size and low idle current draw also make it easier to locate and power in small compartments.
- Built-in LCD display for manual control and amplifier configuration on the unit itself.
- Easy Tune compatible when used with Fusion® stereos that include DSP and the Fusion® Audio app.
- IP67-rated amplifier chassis (excluding cables) for water and dust resistance.
- Ignition protected design for compliant installation in suitable engine compartments.
- Operating temperature range from 4° to 149°F (-20° to 65°C).
| Part Number | 010-03428-00 (AP300/1, monoblock model) |
| Channels | Monoblock |
| 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) | 200 W x 1 (<1% THD) |
| Rated Power @ 2 Ω (14.4 V) | 350 W x 1 (<1% THD) |
| Frequency Response | 10 Hz – 500 Hz (+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 (monoblock/4-channel) |
| 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 – low-pass full-range filter for subwoofer channel |
| Filter Mode | Low-pass only (monoblock) |
| Filter Slope | 12 dB/octave |
| Filter Frequency Range | 20 Hz – 500 Hz (low-pass) |
| LP Variable Crossover | Yes – 20–500 Hz, 12 dB/octave |
| Bass Boost EQ | 0 to +18 dB @ 37 Hz |
| Infrasonic Filter (Subwoofer) | 20–50 Hz, defeatable |
| Output Polarity Switch | Yes – for subwoofer phase alignment |
| 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 AP300/1 monoblock 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.