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Cabinet Effiiciency - How important is the horn?

Discussion in 'Amps and Cabs [BG]' started by Phil Smith, Mar 5, 2004.


  1. Phil Smith

    Phil Smith Mr Sumisu 2 U

    May 30, 2000
    Peoples Republic of Brooklyn
    Creator of: iGigBook for Android/iOS
    My question is when cabinet efficiency is measured what effect or better yet what contribution does the horn make to the overall loudness of the cabinet?
     
  2. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    None at all. The efficiency is measured with the speaker outside the cab in free-air and far enough from any reflective surfaces to prevent sound reflections. They pump a 1k sine wave through it at 1 watt and measure the dB from 1 meter away.

    You'll find the horns have their own seperate sensitivity rating. Aftermarket horns certainly do, though you may have trouble finding this spec on a commercial cab. In a lot of cases, the horn is a lot more efficient than the coned speaker. Have a look at a crossover in a production cab and you'll notice that as well as capacitors (to cut lows) and inductors (to cut highs), there's usually a couple of resistors as well. These resistors are basically an attenuation device to turn the horn down, bringing the output down to something that matches the coned speaker. Most will also have an L-pad to allow you to turn it down further.