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Discussion in 'Amps and Cabs [BG]' started by fatsobasso, Jan 6, 2006.


  1. fatsobasso

    fatsobasso

    Dec 24, 2005
    Ormond florida
    can someone define or explain cabinet SENSITIVITY,lets say you have a 2-12 cab,with 105dB SENSITIVITY?
     
  2. K2000

    K2000

    Nov 16, 2005
    Brooklyn
    It's the efficiency of the cabinet... it's ability to project volume (so to speak).

    Example of low efficiency cab would be 90db
    Example of high efficiency cab would be 105 db

    What that means to you... all things being equal (same head to drive both cabs, same number of speakers etc) the high efficency cab will sound louder.

    My terminology may be deficient, but that is a quick explanation from a layman.
     
  3. fatsobasso

    fatsobasso

    Dec 24, 2005
    Ormond florida
    Thanks
     
  4. BbbyBld

    BbbyBld

    Oct 13, 2005
    Meridian, MS
    Let's say you have a 2-12 cab that has a sensitivity of 105 dB @ 1 watt @ 1 meter, and this imaginary cabinet is rating is 300 watts RMS:

    Every time you double the power you will gain 3 dB of sound pressure. So:

    1 watt = 105 dB
    2 watts = 108 dB
    4 watts = 111 dB
    8 watts = 114 dB

    and then.....

    64 watts = 123 dB
    128 watts = 126 dB
    256 watts = 129 dB

    Let's say you added another identical cab and drove both cabinets equally. This would only give you an additional 3 dB.
     
  5. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    Going from memory when I was dinking around messing with making a cab of my own. So exact I don't recall but I'm sure someone knows to the T.

    Anyway, when I first ran across it I thought it was a misunderstanding or misprint. I recall it being with every spl digit increase it's like doubling amp wattage. I ran across a thread not long ago that said it was 2 digits of spl.

    Regardless, bottomline is it's a lot more practical to increase output with more efficient speakers than bigger amps.

    And that's all I figured I needed to know about it. 3db by the way is basically an audible difference and that's about it. Most onboards preamps are like max 12 - 15db boost/cut so that gives some scale as to a difference that matters.

    There's plenty of technical definitions on the net from a google search. I ran across a bunch of audio/engineering/studio glossaries when I assembled the Bass Tone Glossary in the pup forum.
     
  6. A boost or cut of 15 db EQ is HUGE.
     
  7. Steve Clark

    Steve Clark Supporting Member

    Jan 9, 2004
    London ON
  8. fatsobasso

    fatsobasso

    Dec 24, 2005
    Ormond florida
  9. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Not really. Sensitivity is almost meaningless when its not linked to frequency. For instance, 105dB sensitivity sounds wonderful, but at 3kHz it's pretty meaningless as far as electric bass is concerned. 95dB sensitivity doesn't seem so impressive, but at 50Hz it's quite good, better than most speakers on the market. The difficulty lies in finding out where in the spectrum a speaker's quoted SPL was measured. Most manufacturers aren't saying,
     
  10. Excellent information. Thanks.
     
  11. luknfur

    luknfur

    Jan 14, 2004
    DIXIE

    Yep, concur.

    ==========
    K2000
    Registered User Join Date: Nov 2005
    Location:

    It's the efficiency of the cabinet... it's ability to project volume (so to speak).

    Example of low efficiency cab would be 90db
    Example of high efficiency cab would be 105 db

    ===========

    But try getting the same oucome from an amp and see the difference in size/weight/cost compared to ones exisiting amp vs doing the same with a cab. Breakdown for lessor variation is fairly proportional in my recall.