Hi I have a bit of a hard time grasping the poly config.
I have a kit where I want track 1 to be douphonic (play two notes at the same time) and all other tracks monophonic.
As I understand it I have to borrow one voice from another track and the best track to borrow from is track 4. But when I set track 1 to use track 4’s voice, track 4 also becomes duophonic and I don’t want that.
Have I completely misunderstood this? What should I do?
I think what you need to do is set track 1 and 4 as poly, but not activate ‘use track sounds’
Then, you can play duo-phonically with track one, mono on track 2 and 3, and just don’t use track 4
Unfortunately I need to use track 4 to.
I’m playing the verse of the song with a duophonic pad but when the refrain comes I play the same pad monophonicly with a bass on track 4.
I’m a little confused… 
If you need track 4, then jst make 2 of the other tracks polyphonic.
You have to ‘give up’ one track, if you want one to be duophonic.
Keep you bass on track 4 then, and just select 2 others e.g. 1&2
Does that not work for you? You don’t need ‘use track sounds’ or Unison mode.
Another option would be to try and adapt your pad on track 1 to use p-locks to change the chords, that way you might not have to make that track duophonic. If you use p-locks on each trig to change the oscillator tuning in conjunction with the 5th sub oscillator you might be able to get what you want. Worth a try at least