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Saddle ribbon pickup voltage phase compared to guitar top vibration phase

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  • Saddle ribbon pickup voltage phase compared to guitar top vibration phase

    (long message alert, sorry 'bout that)
    I have been doing a lot of testing with a Duet Master system, which is a blender of
    saddle pickup and microphone and determined that when the invert button is up
    that the master's output on XLR is 180 degrees out of phase with the saddle pickup input.
    As a side note the phase of the saddle pickup input and the mic pickup input are also 180 degrees
    out of phase which I expected because electret condenser mics signals are 180 degrees out of
    phase with the sound wave coming in from the front. (If they are wired common source)
    If this makes sense to you then here's my question:
    Do saddle pickups produce a signal that is opposite the motion of the guitar top (assuming that
    when the top moves forward it produces a positive pressure and a microphone picking that up
    would produce a positive voltage)
    So that as the top is moving forward/positive the saddle pickup's signal is moving negative
    and thus the Duet Master inverts the signal of the pickup.
    I am thinking that compression of the saddle pickup causes a positive voltage, meanwhile
    the string is compressing the saddle it is pushing the top backwards.
    And the reason I'm doing all this testing is that I am trying to come up with a blender for my
    mandolin and want the signal from the pickup in phase with the signal from the microphone.
    Whew! Thanks for reading this far.

  • #2
    The LB6 in the Duet Master has 6 individual sensors, and the G and B are always out of phase from the rest of the sensors. So I'm certain that any phase readings between the mic and the pickup will not be entirely accurate. This is just part of the system's design.

    What kind of system are you looking at for your Mandolin?