Tweeter attenuator through expression pedal

Discussion in 'Amps and Cabs [BG]' started by ihaveaquestion, Jun 11, 2019.

  1. ihaveaquestion


    Jan 9, 2018
    Is it possible to control a tweeter's attenuation with an expression pedal?
    Last edited: Jun 11, 2019
  2. rufus.K


    Oct 18, 2015
    I bet you could, a resistive divider to ground.
    ihaveaquestion likes this.
  3. ihaveaquestion


    Jan 9, 2018
    Do you think it could be made by anyone with experience in electronics, or should i trust only someone who deals with musical stuff?
  4. BogeyBass

    BogeyBass Inactive

    Sep 14, 2010
    Use to be able to buy empty crybaby wah cases. And use whatever value needed.

    If you could fit the switch in there. And have a long pointless speaker cord.

    Easier if a amplifier had seperate amp and active crossover. Simply control the volume with the head. Even have expression pedal if necessary

    My opinion on tweets is extremely biased unfortunately. You just use a cab without one or turn it off. Call it a day
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  5. rufus.K


    Oct 18, 2015
    You'd be better off with someone with electronics knowledge.

    Off the cuff, add a shorting 1/4" jack to the cab, and have the tweeter in series with it. The expression pedal would be a resistive divider that would shunt it to ground, generally speaking.
    ihaveaquestion likes this.
  6. Bob_Ross

    Bob_Ross Gold Supporting Member

    Dec 29, 2012
    Back in the 1970s or 80s Electro-Harmonix made a stompbox called the Hot Foot which was simply a remote pedal controller for any potentiometer. There were no active electronics in the pedal, no circuitry whatsoever; it was simply a mechanical connection that transferred the motion of the wah-style pedal to the rotation of whatever pot shaft you snapped the attached cable onto.

    Find one of those bad boys and afix it to the existing tweeter attenuator on your speaker cabinet.
    ihaveaquestion and lz4005 like this.
  7. Crater


    Oct 12, 2011
    Dallas, TX area
    The short answer is NO.

    The tweeter level controls on cabs are not simple potentiometers, but "L-pads" that are: 1) designed to have an even resistance as they're turned through their travel. 2) They are large with large resistance elements because they are dissipating multiple WATTS of amplifier power. L-pads always have an impedance and power dissipation rating.

    So, I doubt you'd be able to get the appropriately rated L-pad attenuator to fit inside a crybaby case, and the little plastic rack & pinion system isn't strong enough to turn it. Negative Nancy, I am.

    Just get an EQ pedal.
    ihaveaquestion likes this.
  8. JimChjones


    Aug 6, 2017
    SE England
    Technically I'm sure its feasible. The mechanical side might be awkward, but there's nothing intrinsically impossible. The trick would be to use a cabinet that already has a tweeter volume control and replicate the circuit.

    Musically... what's it going to give you - the ability of to change the tone mid song... I can imagine using a tweeter on/off I suppose, but is being able to vary the volume of the tweeter going to give you anything you couldn't gain much more simply by altering a wah wah pedal so that its a straight treble tone control? Especially as anything you do to the tweeter will surely not get to the PA.
    Last edited: Jun 13, 2019
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  9. lz4005


    Oct 22, 2013
    I was going to suggest an elaborate system of pulleys, but this is even better.
    ihaveaquestion likes this.
  10. That sounds lile it’s based on Neil Young’s original Whizzer. His tech built it for Rust Never Sleeps so he could remotely set the volume knob on his amp to a specific level. That’s how he gets his massive, barely controlled feedback sounds with Crazy Horse.

    He’s long since upgraded to a digitally controlled unit with presets, and, if I’m not mistaken, control over multiple pots.
    ihaveaquestion likes this.
  11. beans-on-toast


    Aug 7, 2008
    Sure it can be done. Attach a motor to the tweeter’s rheostat, control the motor digitally with a midi rocker pedal. Expensive.
    ihaveaquestion likes this.