FA1-400.4 Formula 400 Watt Amplifier

MB Quart FA1-400.4 FORMULA 400 Watt Amplifier 4 Channel Car Audio Amp.

$ 189.99

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SKU: 806576230120 Category:

MB Quart Formula series four channel car audio amplifier featuring innovative sound quality and power technology. The FA1-400.4 is a 400 watt bridgeable car audio amplifier. Formula amplifiers feature DC Sensing to allow any amplifier to be easy integrated into an OEM system by simply adapting a RCA cable from the source unit.

Weight 8.9 lbs



MB Quart










1 Year

Amp Class

Class SQ (Class A/B)

Amp Total Channels


Amp Max Power (watts)


Amp Power @ 2 Ohms (ch x watts)

4 x 50

Amp Power @ 4 Ohms (ch x watts)

4 x 100

Amp Crossover


Amp Variable High Pass Crossover 12dB per Octave

CH1 & CH2: Switched Full/HPF 50Hz-500Hz, CH3 & CH4: Switched Full/HPF 50Hz-500Hz

Amp Variable Low Pass Crossover 12dB per Octave

CH1 & CH2: Switched Full/LPF 50Hz-250Hz, CH3 & CH4: Switched Full/LPF 50Hz-250Hz

Amp Bass Boost


Amp Variable Voltage


Amp Signal to Noise

> 90dB

Amp Frequency Response


Amp Total Harmonic Distortion (THD)

< 0.5%

Amp Speaker Level Audio Inputs

RCA Jack

Amp Power Terminal 12v/GND


Amp Speaker Terminal Wire Gauge

12 AWG

Amp Fusing

20A x 2

Proposition 65 Notice ​WARNING: This product can expose you to chemicals including LEAD, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
Low Noise Preamplifier Circuit

Q-Stasis Pre Amplifier Stage: Maximum low voltage signal from the source unit comes into the amplifier circuit with minimal distortion.

RCA Inputs

Nickel Plated: High temperature impact resistant with hex screw terminals that allow for secure connections and is erosion resistant.

High Level Inputs

DC SIGNAL SENSE: The DC SIGNAL SENSE switch will allow the amp to turn on when a signal is received on the RCA inputs, so an amplifier remote turn on wire is not needed to turn on the amplifier. This feature can also be turned off.

Operation Mode

4 channel operation mode allows either stereo or mono bridged operation.

Crossover Type

Variable electronic crossovers allow for complete control of the sound.

Electronic Equalizer

Control of amplifier output with on-board electronic crossover to tailor specific frequencies to speakers and subwoofers. Check specifications for specific frequencies for this amplifier.

Class / Topology

Class SQ: Multi-channel amplifiers utilize the unique MB Quart Class SQ topology. Matched with Q-Stasis the sonic accuracy and clarity exceeds standard Class A/B amplifiers.

Output Device Technology

FLUID-FETS: MB Quart output devices, FLUID-FETS are painstakingly selected for their ability to efficiently produce power and mimic the sound quality of the highest end home amplifiers.

Heat Sink

Heavy duty heat-sink efficiently moves heat from the MOSFET where it can be cooled.

Power Supply

Rugged MOSFET Pulse Width Modulation power supply: Allows amplifier to product efficient power without taxing the vehicle electrical system.

Output Connections

Heavy duty connections allow for secure electrical signal to pass into wiring and resist erosion which will add longevity to the amplifier.

Connection Type

Secure connection for all power, ground and speaker connections.

LED System Protection Circuitry Diagnostics

Monitor overload and speaker short protection with illuminated indicators on the amplifier end panel.

View/Download (12.5 MB)

MB Quart Formula Amplifiers (FA1) Quick Start Guide (Rev3)

View/Download (1.1 MB)

MB Quart Autosense Technical Guide (Rev3)