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MB Quart

MB Quart RA1-280.4 Reference Series 4-Channel Car Amplifier - 50W RMS x 4

MB Quart RA1-280.4 Reference Series 4-Channel Car Amplifier - 50W RMS x 4

Regular price $199.95 USD
Regular price $300.00 USD Sale price $199.95 USD
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MB Quart RA1-280.4 Reference Series 4-Channel Car Amplifier - 50W RMS x 4


MB Quart's Reference Series RA1-280.4 four-channel amplifier provides 50 watts of power to two pairs of speakers, so you can hear and feel your music clearly over road and engine noise. Designed to power high-quality aftermarket speakers, like their Reference Series speakers and components, this Class D amplifier utilizes MB Quart's unique Q-Stasis (Class SQ) circuitry to improve the accuracy and clarity of your music.

Versatile features

The amplifier's features include speaker-level inputs with signal-sensing amp turn-on, so it's ready to work in almost any system. A high-pass filter shapes the signal to fit your full-range speakers for their best-sounding output. You can also configure this amp for two-channel operation to power a pair of subwoofers with up to 140 watts each or for three-channel operation to power a pair of speakers with 50 watts each while powering a sub with 140 watts. A low-pass filter and a bass boost EQ help dial in just the right kind of bass bump you like.

Product highlights:

  • 4-channel car amplifier
    • 50 watts RMS x 4 at 4 ohms
    • 70 watts RMS x 4 at 2 ohms
    • 140 watts RMS x 2 bridged at 4 ohms
  • variable low- and high-pass filters (50-250 Hz, 12 dB/octave)
  • variable bass boost (0-9 dB at 45 Hz)


More Info:

  • preamp and speaker-level inputs
    • speaker wire-to-RCA adapters required for speaker-level input
    • DC offset-sensing turn-on with speaker-level input
  • wiring, fuse, and hardware not included with amplifier
    • 4-gauge power and ground leads and a 40A fuse recommended
  • dimensions: 12-1/2"W x 2-1/4"H x 5-7/8"D
  • warranty: 1 year
  • MFR # RA1-280.4


What's in the box:

  • 4-channel amplifier
  • 4mm Hex key
  • 2mm Hex key
  • Four 5/8" screws
  • MB Quart logo badge (taped to the top)
  • Quickstart guide