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Usable low frequency???

Discussion in 'Amps and Cabs [BG]' started by brother bean, May 20, 2005.


  1. brother bean

    brother bean

    May 23, 2003
    How are all the cab manufacturers determining the usable low frequency of there product? Is there some kind of acceptable standard test?
     
  2. It used to be -3db. I guess now it is like 10db, and that is if they are being honest. Most simply omit. That said, not always a good idea to pick a speaker by numbers. A standar ported cab will have a tuning frequency, whcih you can consider its usable low end limit. Sealed cabs have smooth rolloff and can play lower frequencies but at an attenuated level. Not sure how transmission lines are spec'd. I know they supposedly play lower than tuning frequency- but only EA makes them.
     
  3. brother bean

    brother bean

    May 23, 2003
    Not to sound ignorant or anything but when you say -3db and 10db, what does that mean? Is this judged from the avg spl?
     
  4. Well, frequency response is plotted out on a graph. It looks like a jagged montain. It should look like a plateau- nice and flat and high. Being up high shows how loud it is (SPL). The peaks and dips represent how loud it is playing a particular frequency. From left to right it goes from bass to mids to highs across the sound spectrum. It is usually measured from 20 cycles/per second (hertz or hz) to 20,000 (khz). So if you want bootay bass you feel in your gut, you are looking for the response down low like 40-60hz. If you like pucnhy chest thumping bass and good definition, then you lare looking at bass from 70hz-400 hz.

    Don't worry about fundementals, most of the energy is not in the first octave. If you have a five string with a low B, the fundemental is around 31.5 hz. You would be wasting power trying to reproduce 31.hz faithfully.

    In sum, just worry about how it sounds and not the numbers.
    Home hi fi is a little different. You want to carefully examine the specs of a home subwoofer or the flatness of a speaker.

    So the -3db point shows where it starts to "roll off" and get softer. down by 3 decibles. You probably know that db is a unit of measurement for sound. But it is algorythmic so even though 3 db may seem like much of anything, it can be as much as twice as loud or little as half as loud.