Hi David

I worked it out, bit of a head scratcher.

Logic X won't let you send on two midi channels to the Polaris at once unless it is set up as one multitombral output. The Polaris looks like it gets confused by two streams coming in as in having two separate logic instruments connected to two different midi channels.

So the solution is create one multitimbral external instrument which then links two tracks together and sends information presumably down one stream as it were instead of two separate standalones or one non multimbral track.

Got there!

Many thanks