balance loudspeaker volume

Discussion in 'The Projects Forum' started by yoamocuy, Mar 3, 2015.

  1. yoamocuy

    Thread Starter Active Member

    Oct 7, 2009
    I've got a group of loud speakers that are used to play radio programs from time to time. Each loudspeaker has a different cable length and as a result the loudest loud speaker is drastically louder than the quietest loudspeaker. Ultimately I need to balance the sound. I was thinking of just attenuating the sound of all the loudspeakers so that they match that of the softest loudspeaker but since these are consuming a large amount of power i dont think i can just put a resistance in series with the cable to drop the volume... I was thinking of an l pad but thought id see if anyone had other suggestions
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    It depends on what resistance the speaker cones are, and if they are used on a PA system, or just from an amplifier?
  3. MrChips


    Oct 2, 2009
    How many loudspeakers are connected at the same time?
    How far apart are the loudspeakers?
    How are the loudspeakers wired together?
    Are the loudspeakers the same, i.e., are they identical?
    What is the impedance of each loudspeaker?
    What amplifier or device is driving the loudspeakers?

    The devil is in the details.
  4. wayneh


    Sep 9, 2010
    Cable length should have no impact on volume. If it does, you need a lower gauge (fatter) cable.
    ebeowulf17 likes this.
  5. Denesius


    Feb 5, 2014
    Also make sure the polarity on all the speakers match that of the amplifier output. For example, if one speaker out of 4 is reversed, to the ear it will sound quite a bit lower volume than the others.
  6. #12


    Nov 30, 2010
    Speakers vary quite a bit in quality. It is much more likely that your speakers are not the same quality as each other compared to the connecting wire causing problems.
  7. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    Can you answer MrChips questions in post #3? Can you swap the soft speaker with the loudest one, and see if the problem also moves? This will isolate the problem to either the speaker or the wire and amplifier. Make sure polarity is correct so that you don't introduce another problem.
  8. alfacliff

    Well-Known Member

    Dec 13, 2013
    the normal way to do this is to use a 70 volt wireing system. each speaker has a 70 volt transformer with taps that allow you to set the power available at that speaker. by stepping up the voltage, you reduce resistave losses in the speaker wire.