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nice to find out the truth sometimes

Discussion in 'Amps and Cabs [BG]' started by K Dubbs, Nov 5, 2002.


  1. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    Tell me if the fault is actually on my end as far as this goes. I hooked up my rig to a frequency generator and sweeped the frequency from 55hz-300hz. My speakers are supposedly rated from 55hz-13khz +-3dB. -3 dB's means a third less volume by my understanding. Well the tone was way louder at 100hz and up than under 100hz. In fact, at 55hz, the tone was barely even audible. If I understand quoted specs incorrectly, that's one thing. If the case is actually that the thus far unnamed bass cabinet manufacturer quotes false frequency response, then that ticks me off. Maybe some of the rest of the TB'ers have tried this and can offer some insight.

    There are very few things in this world that really get me on fire, and one of them is fire, and the other is when someone lies.
     
  2. Could be the nature of human hearing, depending on how much power you were pushing. The Fletcher-Munson curves show that at lower volume levels, bass sounds much lower than midrange or treble. I think the only way to factor out your ears is to use a test microphone and actually measure the signal that the microphone "hears".

    Do a search for Fletcher-Munson curves and you'll see what I mean. It's the reason most stereo's have a "Loudness" button that boosts Bass and Treble at lower volume levels, so the ear will hear what sounds like a "flat" signal.

    Having said all that, my guess is that your cabinet does not live up to its specs, although it probably gets pretty close. Also, don't sweat it, because everything under 80 Hz is not as important as people seem to think it is.

    Chris
     
  3. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    thanks throbbinnut for your insight. Yeah i'll take a look into the Fletcher-Munson curves.
     
  4. those specs are not always real-world numbers. It was especially bad in car audio in the 70's; they would tell you the amp had 100wRMS. What they did not tell you was that was at 10% distortion!

    It could be your amplifier too, unable to faithfully reproduce signal content in the freq. range below 100Hz.
     
  5. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    at any rate, my power amp shouldn't be the problem
    i'm using a carvin dcm 1000 power amp and running it through a "high quality" name brand 210 cab
     
  6. Well 55 to 13K + or - 3 db doesn't leave much room for BS. The manufacture probably never counted on someone actually testing the product to see how it really worked. My SWR Triad is rated -6 at 37 - 16K and it is a 3 way cab with a 15-10-and horn and a passive x-over. So I just think your cab has BS for specs. But, does it really matter?
     
  7. fast slapper

    fast slapper

    Dec 11, 2001
    Fresno, CA

    What 2x10 is it?
     
  8. fast slapper

    fast slapper

    Dec 11, 2001
    Fresno, CA
    I recently tried that with my Epifani 2x12 and the results were what the specs said it would be. A little under 40 hz is where the most dramatic drop in volume took place.
     
  9. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    worry more about how the cab sounds then it's specs. yeah it sucks being lied to (i know how you feel) but the way it really sounds is what matters... right? ;)
     
  10. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    actually it might be higher than 13khz, i dont remember, but im' positive of the 55hz mark
    its an ernie ball hd210. great sounding cabinet to my ears, and i'm going to keep on using it, but i hate when people lie.
     
  11. The only way to tell if the response is -3dB at 55Hz is to get an accurate SPL meter, and measure the SPL at a bunch of frequencies through the sweep. They're probably not lying, there's a huge difference between the perceived loudness of a certain SPL at 100Hz and at 55Hz. Like Chris said check out the Fletcher/Munsen equal loudness curves. You might be surprised. Of course, they may be lying! :D