Help needed for active wireless loudspeakers

Discussion in 'Analog & Mixed-Signal Design' started by AMandler, Nov 4, 2018.

  1. AMandler

    Thread Starter New Member

    Oct 27, 2018
    I am in the process of building a set of 2way active wireless loudspeakers. I must say however, that I need guidance and help in certain areas of speaker building, especially with regards to active speakers.

    I am here because I need help designing the schematics diagram of the involved systems. In other words, a schematic diagram specifying how the respective modules/systems will be connected schematically on a completed unit (active loudspeaker). See specs below-

    Per Sealed Cabinet unit-

    1. Amplifier - TDA7396 bridged class-AB amplifier
    2. Crossover – 2 way
    3. Connectivity - AirPlay 2, Play-Fi, Bluetooth.
    4. Tweeter - 1 X Tweeter (4 ohms)
    5. Woofer - 1 X Dayton Audio ND91-8 3 -1/2" (8 ohms)
    6. Power - 1 X Switching power supply = 24V, 2500mA
    7. Battery - 4 cell Rechargeable Lithium Ion 16.8 V Batteries plus Lithium Battery Charger and Balance Protection Board (voltage detection and cutoff circuit).
    8. Cabinet - 1 X Internal volume: approximately 0,8 liters / 0.03cubic feet

    I will be eternally grateful, and offer a set of the loudspeakers above in appreciation of services rendered to anyone who can help me accomplish my goal.

    Thank you.
    Last edited: Nov 7, 2018
  2. Sensacell


    Jun 19, 2012
    (sound of crickets chirping)

    You are asking for high-level engineering design that would cost $20,000.00 - $60,000.00 if you hired a professional.

    - In exchange for a speaker I can buy for $20.00
  3. crutschow


    Mar 14, 2008
    To minimize power consumption you might want to consider Class-D switching amps.
    TI, among others, make several versions of such amps.

    Are you interested in doing some added things that might improve the sound or do you just want a minimal system that sounds okay.
  4. AMandler

    Thread Starter New Member

    Oct 27, 2018
    Thank you for your reply.

    And please allow me to start by stating how much I appreciate your assistance.

    I started out with a desire to implement a Class-D amp, but was advised against it. You are welcome to read the grounds on which this was based here:

    I am a novice on the subject, and was inclined to follow the advice. I am however prepared to track back to my original choice, which was the Class-D amp.

    Specific areas of importance are above all else; quality audio, relatively compact pcbs´, the avoidance of too much heat, and last but not least, a highly stable system, with quality components and low distortion.

    P.S. A definite choice of tweeter has not been made at this time.
    Last edited: Nov 7, 2018
  5. Audioguru


    Dec 20, 2007
    The new 3.5" woofer is not the original 4" one selected before. Its sensitivity is fairly poor at only 82.1dB/1W/1m so with a TDA7396 bridged amplifier powered by a 16.8V fully charged battery feeding its 8 ohms at 13W then it will not be loud, but the tiny woofer in a small sealed enclosure doesn't produce any deep powerful bass anyway.

    A review of an ebay Bluetooth input class-D stereo amplifier board said its rated 100W was actually only 20W but it sounded fine. One of its cheap connectors fell apart.
    But this wireless speaker is for mono. The Bluetooth receiver has two outputs for stereo. One Bluetooth receiver can be used for the left channel and another Bluetooth receiver can be used for the left channel, then there will be stereo.