BLX4 - 120 Watts RMS x 4 @ 4 Ohm Full Range Bluetooth Amplifier

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$ 279.95

Massive Audio NANO "BLU" Series Amplifiers. Our CTA 2006 certified NANO BLU amps are only 4.25” W X 1.6” H and range from 6.5" to 10.86" L. All models feature Digital Platforms, Built In OEM Line Converters, Up to 9V In, Line Out, Auto Turn (no turn on wire needed) with 12V out and support a USB which accommodates the optional UBT1 Bluetooth Dongle for audio streaming. All Nano "BLU" Amps use nickel plated RCA inputs and circuit boards are sprayed for water resistance and then everything gets shielded in a rust proof aluminum housing. Each model supports a "Docking Port" to plug in an optional custom matching Railcap Booster (RCLX).


  • Extreme Power in a Mini Compact Footprint
  • Conformal Coated PC Board to Resist Moisture, Dust and Extreme Heat
  • 1 Ohm Stable Design (BL1, BL3, BL4)
  • 4 Layers PCB design with SMD parts
  • Built-in Noise Reduction Circuitry
  • Full MOSFET with High Grade Switching Devices
  • Bluetooth Audio Streaming with (Optional) UBT1 Dongle (BLX2, BLX44, BLX48, BLX5)
  • Built-in Auto Sensing Turn On Function (Hi-Inputs)
  • 12V Remote Output for External Devices (Hi-Inputs)
  • -3 ~ + 12DB Variable Bass Boost 40 Hz - 100 Hz (BL1, BL3, BL4)
  • -6 ~ + 12DB Variable Bass Boost 40 Hz - 200 Hz (BLx5)
  • Advanced 5 Way Protection Circuitry
  • RCLX ~ Railcap Booster (Optional)
  • World Wide Standards Compliant (RoHS, E-Mark, CTA-2006, CE)


    Peak Output Power @ 14.4V 480W x 2 Max
    1 Ohm RMS n/a
    2 Ohm RMS 240W x 4
    4 Ohm RMS 120W x 4
    4 Ohm Bridged 480W x 2
    Input Level 0.2~9.0v
    Freq. Response 10Hz~25KHz
    THD at 4 Ohm Load 30% Rated Power <0.03%
    S/N Ratio >90dB
    Bass Boost N/A
    Minimum Load 2 Ohm Stereo
    Gain Remote n/a
    Dimensions 1.6"H x 4.25"W x 8.50"L

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    • What gauge wires (Power, Ground & Speaker) do you recommend are used with the BLX4?

       4 Gage power and ground ......... 100% pure copper (AK-4 kit) on the BLX4    14 -16 gauge speaker wire   Thank you for your Massive Audio support.

    • For the Massive Audio BLX4: What channels pass through the line out? Are the RCA inputs really speaker level inputs? Do you provide hardware to adapt speaker wire to RCA inputs? Can you send me a manual for this amplifier? Thank you very much for your time!

      Yes the RCA inputs will take speaker level up to 9V direct in turning on the ATO (Auto Turn On). the Line out is Full Band from both channels. The RCA hilevel speaker leads used are called "UW-1" and is an optional accessory. The user guide is located on the TAB next to this Questions Tab - or use this link - 

    • I just installed the BLX4 on my 2010 Victory Cross Country. when the amp is powered up there is a loud hissing sound coming from the speakers. we have trouble shot everything to see what is causing the noise and have not figured it out. the only thing I haven't done yet is change the audio source to see if the noise goes away. If the voltage coming from the stock radio is higher than 9 volt can that cause the noise problem. I am using a basic speaker wire to RCA adaptor.

      I suggest using a Ground loop noise isolator.   


      it may also help ( depending on your setup ) if you connect the negative from your head unit directly to the negative (ground) of the amplifier.

    • Can I add the UR1 bass controller to the BLX4?

      So sorry but our BLX4 is a 4 channel amplifier and does not use a UR1 remote knob. Only our mono amplifers and our 5 channel. Thank you.