This discussion is locked
renegade47n

Q: Confused about signal flow in aux busses

I'm using Logic Pro 9, and I guess I don't understand how it's routing the signal to Aux channel strips. Based on what I know and what's in the user manual, this is what I would expect to happen:

I set up an aux channel strip with a delay effect, and want to run multiple signals through it to save processor power and time messing with individual plug-ins. I choose to route a guitar through this aux strip using the Post Fader or Post Pan setting, and drag the send knob up to max. This should mean that the entire signal from the guitar is routed to the aux channel, and I should hear no dry signal coming through the mains.

However, I seem to be getting the same amount of dry signal, no matter how high or low the send knob is set. Instead, what seems to be happening is that the signal isn't "splitting" when I turn up the send knob, with part of it routed to the aux and part still flowing through the guitar channel, but doubling. I.e. if I turn up the send knob all the way on the guitar and mute the aux delay channel strip, there is absolutely no change in the amount of dry signal I hear coming through the guitar channel. Then if I unmute the Aux delay, I get equally loud signals coming through both channels. The only difference is, the Aux's signal has delay.

Is there something funky about this, or am I just mixed up? I'd really like to know exactly how the program routes signals to Aux channel strips.

Logic Pro 9, Mac OS X (10.6)

Posted on Jul 25, 2010 7:35 PM

Close

Q: Confused about signal flow in aux busses

  • All replies
  • Helpful answers

  • by the-design-guy2,

    the-design-guy2 the-design-guy2 Jul 26, 2010 8:44 AM in response to renegade47n
    Level 1 (35 points)
    Audio
    Jul 26, 2010 8:44 AM in response to renegade47n
    I'm not sure I understand your question correctly, but I think you have a misunderstanding of the Send knob. The Send knob does not attenuate the direct signal, it (in addition) sends a percentage of the signal to the Aux bus. The signal sent to the Aux bus comes back to the main I/O with the effect on it. In general, you should have the effect set to 100% wet in the Aux bus.

    If you want the effect's mix control to control the amount of dry signal as well, then you need to instantiate the plug-in on the guitar track itself.

    The effects from the Aux channel add to the dry signal the output of the Aux track...which, if you have the effect mix set to 100% wet, is just effect. Hence your main outs carry dry signal from the guitar track plus effect from the Aux track.