The Part note range are the notes the arpeggiator can use to play, to generate sound, the Output.
The Arpeggiator note range are the notes that can trigger the arpeggiator, the Input.

The way you had it configured was the reason why the arpeggiator could only play a small set of notes. When you play a note outside the Part note range, in your case the Arp would be triggered, but no sound would be heard because the notes the Arp generates are outside of the allowed Part note range.

More info:
https://www.yamahasynth.com/ask-a-question/modx-arpeggio-hold-on#reply-106251

Hi,
I found that when I set a part to a small note range to trigger an arpeggio and then set the 'arpeggio note range' (these are different note ranges)

No, they are not. The Note Limits that trigger the Arpeggio and the Arpeggio Note Limit range are the same thing.

What is different is the Arpeggio Note Limit range — the Notes that start and give input commands as to what key/chord to play.
Then there is the Part Note Limit range — the Notes that the Part in question will actually sound.

These are set in separate places:

On the Performance HOME screen, each Part has a “Range” parameter which sets the Note Limit and Velocity Limit for the Part. These are the pitches and the velocities that will cause sound from this instrument Part.

From the HOME screen > touch “Motion Control” > “Arpeggio” > in the upper right corner touch “Range” > here is the “Velocity Limit” and “Note Limit” for controlling/triggering the Arpeggio for each Part, if one is assigned to the Part.

“Part Note Limit” - what sounds
“Arp Note Limit” - what triggers/controls

If you are working with a Drum Kit Part playing an Arpeggio Phrase... you would set the “Part Note Limits” to restrict which drum notes will sound... say you just want to hear the Kick-Snare-Hihats of the Drum Kit... you might set the Part Note Limits = C1-B1. This will eliminate the Crash, Ride, cowbells, Latin Percussion etc from sounding. Say you only want the Latino Percussion to sound you would set the Part Low Note Limit to C3 and the Part High Note Limit C6

Say you only want the Hihats from a particular drum Arp Phrase setting only F#1 ~ A#1 to sound will mean just that range of Notes in this Part will sound.

Meanwhile the “Arpeggio Note Limit” restricts which Notes will cause the Arp to start play... you could hide this note anywhere on the keyboard... they do not have to be inside the Part Note Range at all... say you wanted to play a rubato piano introduction, and wanted the drums to start only when you played C5 at a Velocity greater than 100... (the last note of your introduction) by setting the Arp Note Limit for Velocity to 100-127 and the Arp Note Limit for trigger and control to C5-C5. Only triggering that Key at 100 or above would start the Hihat Arp Phrase.

Here’s a musical example, the Part Note Limit sets the Split point for your Bass when you are playing the Keys directly. You might create Part 1 acoustic Bass C-2 through B2, and your acoustic piano C3 through G8. But if you do not want your right hand (notes) from instructing the Bass running an Arp Phrase, you would limit the Bass’ Arp Note Limit to just the region not reserved for piano. You don’t want the upper range of the keyboard sending instructions to the Bass phrase.

These two separate parameters allow the notes sounding from the Arp Phrase to be different from those controlling it.

Thank you Bad Mister and rudy for your answers, now I understand this, checked and it is working as expected.

As I wrote above my target is to be able to stop active arpeggio from being heard just by hitting the keyboard on a specific range which can be much more convenient than pressing a scene button, stop button or using a foot switch control.

In my case I created my custom arpeggios as 'fixed' (not drum kits) and each arpeggio is triggered using a single key on the keyboard.

So the trick is to save the arpeggios as "Org Notes" (instead of "fixed") and set the following:
- Set "Org Root Note" to the correct note when creating the arpeggio.
- Set "part note limit" to cover the notes to be heard.
- Set "arp note limit" to cover the triggering key and also go high enough so when the keys are hit then the arp notes will be transposed outside of the "part note limit" and so the arp will not be heard.

Thank you.

There are also other ways. Sometimes I set a keyboard range as a trigger to motion sequence which, in turn, will "mute" a given Part. I may have a fast run I want with a certain set of instruments and the last note at the top of the run to mute a Part so I can quickly come back down the run without that extra Part there (and not enough time to play a double-handed run and also fool with the Scene buttons - and not the desire to carry a foot controller to do it that way).

Or you could setup a one-way switch such as a separate FM-X Part that only has one key it responds to and, once pressed, will "drone forever" that note. You can output this FM-X Part to "Off" (meaning not heard) and use Envelope follower of that Part to squelch another Part's output.

Or ...

There are a number of options available to get from here to there. Creative use of the system is the fun of synth programming.