Hi Zuki,

If you want to use only the styles of the BK7m, then the hookup is easy. Once you have your midi and audio cords plugged in, then turn you PA on in split mode and put the Bk7m in midi wizard mode. When it asks you to play upper 1 and 2 just push a key to the right of the split zone. For lower and mbs just push a key to the left of the split zone. Now you should be all set. If you want to use the BK7m, just turn on the sync start button and it will play and follow the chords you play in your left hand on the PA. The hardest thing to remember is if you want to use the PA arranger, you need to turn off the sync button or else you'll have the Bk7m playing too. I use a Bk7m with my DGX 670 and it works well (I plug the Bk7m outs into the input of the Dgx 670).

If you want to use the voices on the BK7m, then I recommend using a second midi keyboard with the PA. I have a PA 5x (and had a 4x in the past), and from my understanding if you wish to use the BK7m voices you need to make a dummy voice on the PA that sends the correct midi signal for Upper 1/2 and that does not play the "local" voice on the PA. For me it's much easier to just add an inexpensive second midi board set to the channels of Upper 1 and 2. You can even use MBS as a third voice channel and also play that on the keyboard. There are some midi boards with pads where you can program in the Roland sounds you like best at a push of the button. And of course you still can use the Roland app to easily select voices from an iPad.

I hope that helps. I have 2 BK7ms and just decided to sell the second one of them today since I really don't need 2 and they are hard for people to find.