tweeter whistle?

Discussion in 'Amps and Cabs [BG]' started by shatner, Mar 3, 2005.

  1. shatner


    Sep 22, 2004
    Isle Of Wight, UK
    I still have a whistle through my rig when I turn up the treble and volume. I thought it was microphonic tubes originally but I've got rid of my Ampeg. I now have a Sansamp RBI going into a QSC RMX power amp then into Ampeg SVT cabs (2x10 and 1x15). The 2x10 has a tweeter. Do tweeters often give out high pitched feedback-like whistles when cranked?

    All I have to do is crank the treble slightly on my EMG BTC pickups for it to feedback. Funnily enough, the Dimarzio ultra jazz/J retro combo doesn't do the same thing. Maybe the treble isn't as boosted on the John East.

  2. Figjam


    Aug 5, 2003
    Boston, MA
    Yes tweeters often hiss.
  3. shatner


    Sep 22, 2004
    Isle Of Wight, UK
    It's not a hiss. It's a very loud high pitched scream.

  4. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    If you have highs cranked, "normal" hiss can sound like a more pure tone.

    Hiss is wide band noise. If you boost a narrower band, and there is hiss, it sounds progressively more like a tone the narrower the boost is.

    Feedback will be a tone, usually a fairly pure tone, like whistling if at a higher frequency. And it will often change drastically if you move, adjust volume, etc. The amount you turn the gain won't be "proportional" to the change, and the tone usually changes a bit with gain also. I am sure you have had feedback before...

    When you say it sounds like a "scream", that doesn't suggest a tone, like whistling. It suggests a "ragged" sort of whistle, which is what you might get if you just have a lot of boost, between the horn and whatever is on the pre.

    I wouldn't suggest turning the horn up ALL the way. I'm not fond of turning up any of those little horns very far, I don't think ours or anyone's little horns sound great except maybe as a little bit of "gloss".

    Besides, why risk having the local "save the bats" committee calling on you?

    Of course, tastes differ.
  5. Bassic83


    Jul 26, 2004
    Texas, USSA
    Unplug the 210, try it. If there is no scream, then it's your horn, or it's the L-pad. If it still screams, check the preamp. There is a small trim pot for the highs I believe- turn it down 50%. Button it up and try it again. It could be your pre is overdriving the treble it's receiving.
  6. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis

    Neither the horn nor the L-pad can "make" sound where there isn't any. The amp has to supply it.

    Usually a bad horn will sound really scratchy, or make no sound. But it won't make noises on its own, it just reproduces or distorts what comes in.

    It might distort pretty badly.....that COULD be it.....I suppose. Distorted noise?

    If you un-plug the 210, its pretty unlikely that the 15 will even reproduce that same range. So I'd reckon that would get rid of most of the scream. You might have to listen hard to see if the same character is in the sound from the 15.

    I'd start by turning the horn down, then I'd see if you really needed all that treble boost.
  7. ashbory


    Jun 13, 2000
    The Hammer
    Originally Posted by shatner
    It's not a hiss. It's a very loud high pitched scream.

    Is it a sound like "tweet tweet?"

    - If it is, then its probably your tweeter. :bag:

    Sounds to me like it might just be good old fashioned feedback. Does it go away if you keep the volume the same and move the bass far away from the speaker?