I have a Performance on my MoXF8, where I wish to split piano from note C1 upward (for left hand chords & right-hand lead), and a bass from B0 downward only to trigger the bass arpeggios. The bass arpeggios use higher notes than the trigger note, so if I set the voice note high limit to B0, I only get the part of the arpeggio from B0 down, and not the whole arpeggio.

Fortunately, the PART Note Limits can be set separately from the ARP Note Limits.

Instead of using the PERFORMANCE CREATOR > SPLIT function... set your split point manually here's what I mean

Press [EDIT]
Press [COMMON]
Press [F1] GENERAL
Press [SF2] PLAY MODE
Set the SPLIT SWITCH = OFF
This will allow you to manually set the PART Note Limits - within each PART>

The PART Note Limits determine which pitches are going to sound... so you can set the Bass to full range, if you'd like.
The ARP Note Limits determine which Keys on the keyboard are going to control what the Bass plays.

Set your PART Note Limits: C-2 through G8
Set your ARP Note Limits: C-2 through B0

Press [EDIT]
Press the Track button [1]-[4] that corresponds to the Bass PART
Press [F1] VOICE
Press [SF3] LIMIT
Here you can set the PART Note Limits for the Bass: C-2 through G8
While you are here, press the button that selects the LEAD sound and Set the PART Note Limits for the Lead to C1 through G8

Next:
Press the dedicated [ARP ED] button
For the Bass PART you want to:
Press [F4] LIMIT
Here you can set the ARP Note Limits for the Bass: C-2 through B0

If the Bass line that is output by the arpeggiator is an octave too high or too low, while in the ARP ED area > Press [F3] MAIN button and find the parameter "OUT OCT SHIFT". This does just what you think... it will shift the octave of the Bass arpeggio line.

Hope that helps. Let us know.

That did it! So much ability on this fine machine.