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Ampeg B-15 Portaflex Frequency Response Curve

Discussion in 'Amps and Cabs [BG]' started by AlexFeldman, Aug 22, 2005.


  1. AlexFeldman

    AlexFeldman

    Jun 18, 2000
    Chicago, IL
    Can anyone post frequency response data for the vintage Ampeg B-15 cabinet?

    Thanks!
    Alex
     
  2. ESP-LTD

    ESP-LTD

    Sep 9, 2001
    Idaho
    I bet the response curve wouldn't sell a lot of amps these days. I'm guessing 3db down at 90hz and 20db down at 40hz. I'll be interested to see the actual measurements if someone has them.
     
  3. AGCurry

    AGCurry

    Jun 29, 2005
    Kansas City
    I believe that some were made with ports. Mine, circa 1964, is not ported. If it's not ported, it would really depend on the driver installed. I believe in general that the B15-N really is heavy in the low midrange area, light below 80 hz, and, if it uses the CTS square-magnet driver, virtually nonexistent above about 1600 hz.
     
  4. morebass!

    morebass! I'm listening

    May 31, 2002
    Madison WI
    I have a '64 too. It's not ported in the strict sense of the term but is not sealed either. The baffle is "leaky". I'm a big fan of it's tone and have tried to replicate it with larger cabinets for more volume, albeit unsuccesfully. There is a string on that effort from a while back.
     
  5. AlexFeldman

    AlexFeldman

    Jun 18, 2000
    Chicago, IL
    I'm trying to hit that low mid bump with my amp's EQ section (sweepable midrange). I'm working with an engineer to try and emulate the B15 cabinet with a 2x10. Maybe I should quit screwing around and just buy a real portaflex. :)
     
  6. morebass!

    morebass! I'm listening

    May 31, 2002
    Madison WI
    In my quest for B-15 tone I was told by the tone gods here on TB that the EA Whizzy cabinet was the way to go. I never got one because I need more volume than that. Even 2 whizzys would probably not be enough for me. So I've been playing around with EQ too. Not much luck so far. I had some success with a GK 400 RB with the low-mids boosted but my cabinets are the weak point. 4x10s don't seem to do it. I have a '64 B-15N for reference. Another idea would be a Mesa-Boogie D180 with their single 15". You might have to find one with the EQ. The cost of that rig would probably be as much as a B-15R but it would get louder. I never tried it though so it's just a guess.