Rockford Fosgate M2-300X4

Features
Controls
Connections

Features

Overview: The Rockford Fosgate Prime M2-300X4 is a 4-channel full-range Class D amplifier. It's effectively two full range 2-channel amps built into one chassis, labeled Front and Rear. Each section of the amp is bridgeable, so it can be wired as 4-channel, 3-channel, or 2-channel.

CEA-2006 Compliant: CEA-2006 is a system of testing and measurement for mobile audio amplifiers. This voluntary standard advocates a uniform method for measuring an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring amplifier power uses a DC input voltage of 14.4 volts and the RMS power output is measured over a frequency range of 20 Hz to 20 kHz (for full range amplifiers), 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 standards allow consumers to compare amplifiers and receivers under the same conditions (apples to apples).

CEA-2006 Specifications:

• Power Output: 50 watts RMS x 4 into 4Ω
• Signal to Noise Ratio: >70 dBA (measured at 1 watt into 4Ω)

Other Specifications:

• Power Output:
  • 2Ω: 75 watts RMS x 4 (14.4 volts)
  • Bridged: 150 watts RMS x 2 (14.4 volts, 4Ω)

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.

Cast Aluminum Heatsink: The cast aluminum heatsink dissipates heat generated by the amplifier's circuitry. Casting improves cooling efficiency approximately 30% over conventional extruded heatsink designs.

Marine Amplifier: The M2-300X4 is designed for the harsh marine environment. The amplifier features a conformal-coated PCB and UV-resistant finish.

LED Indicator: The amplifier has a top-mounted LED indicator that lights blue when the unit is turned on. The LED lights red when a protection circuit engages (thermal, short circuit, etc.). The amplifier automatically mutes if this occurs.

MEHSA (Maximum Efficiency Heat Sink Application-4th Generation): MEHSA is a Rockford Fosgate proprietary process that increases the heat transfer from the MOSFET devices to the heatsink. The multi-layer insulated metal MEHSA substrate operates with minimal thermal resistance, spreading heat both downward and outward to quickly dissipate heat from each device across the heatsink. This allows greater power output, enhanced thermal stability, and maximum reliability.

NOMAD (NOn-Multiplying Advanced Decision): NOMAD is an intelligent protection circuit that uses an analog computer to make real time decisions regarding temperature, voltage, current and impedance. The amplifier is protected without limiting sound output unless needed.

CLEAN Set-Up: Rockford's integrated level setting technology, CLEAN (Calibrated Level Eliminates Audible Noise), replaces sophisticated test equipment with input/output clip LEDs, allowing you to match the source unit's output to the amp's gain, and optimize the amp's output. The input clip indicator works in conjunction with the audio source volume, illuminating red when the source reaches it's clipping point. The output clip indicator works in conjunction with the input level dial on the amp, illuminating the appropriate color depending on the audio content used for the setup.

Balanced Differential Inputs: Differential inputs eliminate noise picked up by signal cables by measuring the voltage of both the (+) and (-) input signal, then subtracting the voltage common to both conductors (noise), resulting in only the clean signal entering the amplifier.

Controls

Input Switch: Set this switch to match the number of inputs used, 2-channel or 4-channel. In 2-channel mode the signal on the front input feeds all four output channels.

Independent Controls: The M2-300X4 has independent, top-mounted controls for the front and rear channels:

• Gain: rotary gain controls; labeled 0 to 11 (equivalent to 150mV-4V line level or 450mV-12V speaker level)
• Crossover: 3-position switch; choose low-pass, all-pass, or high-pass; low-pass and high-pass crossovers are 12 dB/octave Butterworth
• Frequency: rotary dials; continuously variable from 50-250 Hz

Auto Turn-on Switch: When using speaker level inputs, this switch can be set to On and the amp will turn on when it senses an input signal (DC offset on the left front input). When using the RCA inputs a remote turn-on wire must be connected.

Connections

Power Terminals: The power and ground terminals are nickel-plated set-screw terminals, and will accommodate up to 4-gauge wire. The set screws are tightened/loosened with the included 3mm hex key.

Fuses: The amplifier does not have on-board fuses. A 60-amp fuse should be placed on the power wire within 18" of the battery.

Remote Turn-On Terminal: The remote turn-on terminal is a nickel-plated set-screw terminal that will accommodate up to 8-gauge wire. The set screw is tightened/loosened with the included 3mm hex key.

Speaker Terminals: The speaker terminals are nickel-plated set-screw terminals that will accommodate up to 8-gauge wire. The set screws are tightened/loosened with the included 3mm hex key.

RCA Input Jacks: There are two pair of RCA input jacks for the front and rear channels. The balanced differential inputs are nickel-plated to resist signal degradation caused by corrosion.

RCA Pass-Thru: A pair of nickel-plated RCA pass-thru jacks provide a convenient way to connect an additional amplifier without running an extra set of RCA cables from the source to the amplifier location. The signal from the inputs is passed directly to the RCA outputs. The RCA output is active only when using line level inputs.

Speaker Level Inputs: There are ports for the two included speaker input harnesses, front and rear. If speaker level inputs are used, nothing should be connected to the RCA jacks.