Aloha! Is there a way to have, for example, Piano as the main voice with Organ as the bottom voice and crossfade between the two?
I.e.: Footswitch open with Piano and closed with Organ. I hope I'm making sense! 😀
Mahalo!
Welcome to the forums.
Don't have access to an MX but it looks like the reference doc, on page 52, describes a way to assign a controller to each voice.
https://usa.yamaha.com/products/music_production/synthesizers/mx_bk_bu/downloads.html
Up to six Controller Sets can be assigned to each Voice. Select a Set from Sets 1 – 6 by using the Cursor /[d]
buttons, then press [ENTER]. The Controller Set display is called up.
For each voice:
1. select the foot controller as the source
2. select volulme as the destination
3. select a depth of -64 for one voice
4. select a depth of +64 for the other voice
Moving the foot pedal from full up to full down should gradually lower the volume of one voice and increase the volume of the other.
Here is one video that has a tutorial on editing voices that may help you.
https://youtu.be/8SNlBaghKN8
Let us know if that works for you.