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Don't try this at home!!!!!

Discussion in 'Amps and Cabs [BG]' started by Wxp4759cb, May 18, 2001.


  1. Wxp4759cb

    Wxp4759cb

    Nov 23, 2000
    Kansas City, MO
    I got this 10hz Bass test from some where, and I was like sweet I want to try this through my bass amp, I bet it will rock. Anyway I hooked it all up and started it playing, at first I couldn't hear anything so I cranked it way up. I still couldn't hear it to well but I sure as hell could feel it. I was like this is pretty cool, but then I looked done at the speaker cabs! The speakers were moving in slow motion back and forth about an inch each cycle!!!!!!!! They looked like the woofers on those huge 18s you see at concerts where it looks like the speakers are ripping themselves apart, but these were 10s and a 15! I quickly shut it off. Did I destroy my cones?!?!?!?!?!?!?
     
  2. rickbass

    rickbass Supporting Member

    Well, does it sound okay? No rattles or distortion?

    They don't spec cone excursion for customers on these things. Some speakers can tolerate a lot of travel if they aren't being subjected to it for a significant amount of time.
     
  3. Wxp4759cb

    Wxp4759cb

    Nov 23, 2000
    Kansas City, MO
    They're Peavey, and it was only for about 5 seconds.
    They seem fine now ,but I want to make sure next time I'm playing somewhere important they don't all self-destruct.
     
  4. I´ve several times made an amp "dance" to my music... :D

    that was just cool! :cool:

    I just used my bass though... no 10 hz stuff... :p
     
  5. Wxp4759cb

    Wxp4759cb

    Nov 23, 2000
    Kansas City, MO
    Yeah, the 15 is definantly blown to hell, but it was under warranty so it is "fixed" now, but it still sounds pretty bad! I don't know what is wrong with it! They even put in a entire new speaker, and basket! Also now the 4x10 makes these weird sounds. Its like if you put your lips together and blow like your playing a low note on a tuba! If I turn the tweeter off the sound goes mostly away! But it only is happening on low notes, so why does the tweeter make a difference!
     
  6. Angus

    Angus Supporting Member

    Apr 16, 2000
    Palo Alto, CA
    And what was the point of the 10 hZ bass test?
     
  7. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    To see if his amp could produce the E two octaves below his E string, why else?
     
  8. maybe its just a blown tweeter in the 4x10 then© obviously if the problem goes away when you turn off the tweeter, than the problem is the tweeter©

    lession learned© DONT DO 10HZ TESTS ON YOUR CABS!

    just wondering©©© if 10HZ is an E two octives below a regular E ¥on a bass guitar¤, at 440hz for an A, what woudl a low F# be? ¥e©g© JT¤ ?
     
  9. Oysterman

    Oysterman

    Mar 30, 2000
    Sweden
    You know, I wouldn't even have come up with the idea.

    There are factory specs for this sort of thing. If they say that your speaker won't go down to 10 Hz, it probably won't in real life either.

    Just wondering... don't you feel, sort of, you know, stupid right now?
     
  10. mwlaurenson

    mwlaurenson Guest

    Feb 5, 2001
    scotland
    human hearing begins at 20 Hz anyway, so you wouldnt have been able to hear much.
     
  11. rickbass

    rickbass Supporting Member

    Uh...have you seen BassMasterG? ;)
     
  12. Wxp4759cb

    Wxp4759cb

    Nov 23, 2000
    Kansas City, MO
    10hz isn't that much lower. A low note on piano is like 20 something. I think a low B is 20hz, so just think what JT's basses do!
    P.S. I think I fixed it. The 15 was blown, but I think the 4x10 sounded bad because of some dead batteries.
     
  13. A low B is 30Hz if I recall correctly.
     
  14. Low B is 31 Hz. John Turner talks about some of his esoteric basses that go down to low F# which is 23 Hz.

    It takes a special type of design to get down this low, and yours wasn't it. The speaker destruction occurred because there is no acoustic loading on the cones down that low. I assume your cab is a ported type, so acoustic loading goes away entirely below the tuning frequency of the box. This leaves the drivers literally flopping in the breeze, as you observed. The lack of loading also lets them tear themselves apart as you also observed.

    The only commercial system I am aware of that will reach down this low is the Bag End ELF system. Everything else need not apply.
     
  15. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    The low E on a bass is 40 hz. An octave below that is 20 hz. An octave below that is 10 hz, give or take a little. A low B is 30.9 hz.
     
  16. Angus

    Angus Supporting Member

    Apr 16, 2000
    Palo Alto, CA
    Isn't the low F# about 26 hZ?

    Regardless, I still don't understand WHY the 10 hZ test! Munjis answer made the most sense so far...but do you just not LIKE your speakers? Where did you get this 10hZ test, and what is it normally for?!
     
  17. Possibly some subwoofer test-CD or something.

    Trying to get a bass cabinet this low is plain stupidity.
     
  18. rickbass

    rickbass Supporting Member

    Angus - There's a couple of sources;

    - One is these system test recordings for audiophiles. Sometimes they are 24k gold records that let the stereo system owner drive their speakers into crazy low Hz's/high kHz's and see if their Klipsch speakers are really worth $2k.

    - The other is recordings made by artists like Power Supply who make music with bass tracks so low it seems people are trying to see how long it takes before their car stereos make their transmissions drop onto the street.
    If you play a sample at someplace like CDNOW through your PC speakers the bass track is either inaudible or non-reproduceable.
     
  19. If we are splitting hairs, based on the A440 even tempered scale:


    F# = 23.12465 Hz
    B = 30.86771 Hz
    E = 41.20344 Hz

    Approximately
     
  20. MikeyD

    MikeyD

    Sep 9, 2000
    Test signals at extremely low frequencies serve a purpose - primarily for speaker designers or those who want hi-fi systems that have extended response. However, it becomes very difficult to hear a fundamental below 27.5 - 31 Hz. (low A or B - bottom of the piano's range). Below that, it's very difficult to discriminate pitch. And below around 20 Hz. (varies from person to person), it's difficult to hear anything at all (if a pure sine wave). If you want the shake effect, it might be more effective to get a shaker table to attach to your floor or walls.

    bgavin - thanks for setting it straight again (Pitch Frequency Lesson #334,792)! It's probaby not worth having more precision in the number than about 1 cent of pitch (1/100 of a half-step, I think) for musical purposes. At low B, two decimal places is sufficient. :)
    - Mike