Why Choose Crutchfield?
Great gear and expert advice
Our experts help you pick the ideal gear for your needs.Meet our advisors
Free tech support for the life of your gear.Read about our one-on-one expert help
You may return items that are complete and like new for any reason within 60 days.See the details of our return policy
Earn one point for every dollar you spend and use those points to save on future purchases.Get full details on Crutchfield Rewards
Deep discounts on car installation gear
We offer vehicle-specific installation instructions, dash kits, wiring harnesses, and speaker accessories at deeply discounted prices with car stereo and speaker purchases. Available for most vehicles.Learn more
Trusted since 1974
Our customers have trusted us with their business, and they’ve helped us win awards for our service.Check out our most recent awards
The manufacturer’s warranty always applies.See more details
Rockford Fosgate M750-1D
Mono marine subwoofer amplifier — 600 watts RMS x 1 at 2 ohms
Item # 575M7501D | MFR # M750-1D
This item is no longer available.
Our take on the Rockford Fosgate M750-1D by Crutchfield's Ken Nail
Big power, small chassis
Rockford Fosgate's compact marine amplifiers provide high-efficiency Class-D power for your boat's marine audio system. They meet tough UV and Salt-Fog protection standards, so you can install them with confidence in your pleasure craft, whether you're blasting across inland waterways, or cruising out to your favorite salt-water fishing grounds.
All the inputs you need
Up to 750 watts
The M750-D1 mono amp delivers the power you need to belt out the bass, sending 250 watts continuous power to a 4-ohm load, 500 watts to 2 ohms, and 750 watts to a 1-ohm setup. It's ideal for multi-sub applications. A variable low-frequency filter adjusts the amp's output to your system, and you can use Punch EQ to add a little low-end bump when you need it. You can install this compact amp in a small storage locker or other tight spot.
- marine mono subwoofer amplifier
- 250 watts RMS x 1 at 4 ohms (500 watts RMS x 1 at 2 ohms)
- 750 watts RMS x 1 at 1 ohm (1-ohm stable)
- efficient Class-D design
- conformal-coated circuit board and UV-resistant finish
- variable low-pass filter (50-500 Hz, 12 dB per octave)
- variable bass boost (0-12 dB at 45 Hz)
- CEA-2006 compliant
- preamp-level inputs
- preamp outputs
- 4-gauge marine-rated power and ground leads recommended wiring and hardware not included with amplifier
- 9-1/8"W x 2"H x 6-7/8"D
- warranty: 1 year
- Our 60-day money-back guarantee
What's in the Box:
- Mono marine subwoofer amplifier
- Punch Level Control module
- 16.5' Punch Level Control cable terminated by an RJ25 connector on each end
- 2 Small self-tapping screws (1/2" length)
- 4 Large self-tapping screws (1-1/2" length)
- 3mm Allen wrench
- Installation & Operation Manual (Eng / Spa / Fre / Ger / Ita)
- Amplifier Verification Certificate
Features and Specs
|RMS Power Output (Watts x Channels)||250 x 1|
|Frequency Response at Rated RMS Power||20-250 Hz|
|THD at Rated RMS Power||1%|
|Signal to Noise Ratio||75 dB|
|Peak Power Output (Watts x Channels)||N/A|
|Power at 2 Ohms (Watts x Channels)||500 x 1|
|Bridged Power (Watts x Channels)||N/A|
|Minimum Impedance Bridged||N/A|
|Minimum Impedance Unbridged||1|
|Low-Pass Crossover Frequency||50-250 Hz|
|Low-Pass Slope (dB/octave)||12 dB/oct|
|High-Pass Crossover Frequency||N/A|
|High-Pass Slope (dB/octave)||N/A|
|Bass Boost||0-18 dB|
|Bass Boost Frequency||45 Hz|
|Speaker Level Inputs||No|
|Preamp Outputs||1 pair|
|Parts Warranty||1 Year|
|Labor Warranty||1 Year|
Overview: The Rockford Fosgate Prime Marine M750-1D is a 750-watt mono Class D marine amplifier. It is optimized to power subwoofers, and is 1-ohm stable. The Class D design is very efficient with a cast aluminum heatsink to keep it in a small footprint. The amplifier has 78% average efficiency at 4-ohms.
Marine Amplifier: The M750-1D is designed for the harsh marine environment. The amplifier features a conformal-coated PCB and UV-resistant finish, and conforms to UV and Salt-Fog protection standards.
CEA-2006 Compliant: CEA-2006 is a system of testing and measurement methods for mobile audio amplifiers. This voluntary standard advocates a uniform method for determining an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring power uses a DC input voltage of 14.4 volts and the RMS power output is measured into a 4-ohm load with 1% or less Total Harmonic Distortion plus noise (THD+N). Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4 ohms. CEA-2006 allows consumers to compare amplifiers and receivers on an equal basis. The CEA-2006-rated RMS power output is as follows (measured with a 14.4 volt input, <1% THD+N, 20 Hz-250 Hz):
- 4-Ohm: 250 watts x 1
- 2-Ohm: 500 watts x 1
- 1-Ohm: 750 watts x 1
Cast Aluminum Heatsink: The cast aluminum heatsink dissipates heat generated by the amplifier's circuitry. The inherent advantage of casting provides a 30% improvement of cooling over conventional extrusion heatsink designs.
LED Indicator: The amplifier is equipped with a top-mounted LED indicator which illuminates blue when the unit is turned on. The LED illuminates red when a protection circuit engages (thermal, short circuit, or too low an impedance is detected at the speaker connections). The amplifier automatically turns off if this occurs.
Mounting: The amplifier can be mounted vertically, horizontally, or inverted using the supplied mounting screws; horizontal mounting (right side up) will provide the best cooling.
Amp Controls: The M750-1D has the following top-mounted controls:
- Gain Control: a rotary gain control that can be adjusted from 1 to 11
- Low Pass Filter: a 12 dB/octave Butterworth low pass filter with a crossover point variable from 50 Hz to 250 Hz
- Infrasonic Filter: a variable 15-40Hz, 12 dB/octave infrasonic filter designed to prevent frequencies below the audio range from being applied to the subwoofer
- Punch EQ: a rotary bass boost control, centered at 45 Hz, from 0 dB to +18 dB
Remote Punch Level Control: The amplifier includes a wired Remote Punch Level Control, which is linked to the gain control of the amplifier. The module allows you to remotely control the output level of the amplifier from the dash or center console of your vehicle. The Remote Punch Level Control features a rotary dial, and comes with mounting hardware and a 16.5' connector cable.
Terminals: The amplifier features heavy duty, nickel-plated set-screw terminals. The set screws can be tightened or loosened with the supplied 3mm Allen wrench. The terminals include:
- Power/Ground: will accommodate up to 4-gauge wire
- Remote Turn-On: will accommodate up to 8-gauge wire
- Speaker Terminals: will accommodate up to 8-gauge wire. Two Positive (+) and Negative (-) terminals are provided for installation flexibility. Both terminals are wired in parallel internally.
Fuses: The amplifier does not have on-board fuses. A 60A fuse should be placed on the power wire within 18" of the battery.
RCA Input Jack: The RCA input jacks are nickel-plated to resist signal degradation caused by corrosion.
RCA Pass-Thru Jacks: The nickel-plated RCA pass-thru jack provides a convenient source for daisy-chaining an additional amplifier without running an extra set of RCA cables from the front of the vehicle to the amplifier location.
Our Product Research Team
At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.