The 8Z is not 8 Velocity Zones, (good guess, but incorrect)... here’s what’s happening.

The 8Z is 8 Note Limit Zones... a Normal Voice in the Yamaha AWM2 (sample based engine) consists of 8 Oscillators (called Elements). An Element is a set of parameters including a Waveform. Each Waveform is a made from a set of samples mapped to the keyboard. It can be a complete musical instrument or a layer or building block to create a complete musical instrument.

For example, the pianos in the MX might feature 3 Waveforms, a soft strike, a medium strike and a hard strike set of samples that when layered recreate a dynamic piano. Each Waveform could have a maximum of 256 samples.

A Drum Kit is a Voice where each Key between C0 and C6 (73 Keys) has a different Waveform. A multi sample drum kit would stack 4 or 5 snare drums on the same key and use Velocity to switch soft, med soft, medium, med loud, loud for example...

A Normal Voice is 8 Elements
A Drum Kit Voice is 73 Elements

Normal Voices sustain as long as you hold a key
Drum Voices you do not have to hold the key for the complete sound to play

Normal Voices each Key is one part of making an instrument
Drum Kit Voices each Key is a separate instrument

The details in programming a Normal Voice are different from those for programming a Drum Kit Voice...

The 8Z “Drum Voices” are what would happen if you used the Normal Voice architecture for eight percussion type Waveforms... this allows the programmer to take advantage of the programming details available in the Normal Voice (more control in the Envelopes and Filters, for example)

There are only eight sounds - each is regions to the general area where you would find the principal drums of a standard kit.

C1 and below are the KICK
D1-F1 are very snare like
F#1-A#1 are recreating a hihats Type Sound
Etc...
Play across the keys you see/hear that there are eight distinct regions... and when played with a drum Arp basically conform to where the principal drums are located. After all, as a performing musician you probably never played in a band with a drummer with a 73-piece Kit... more likely they had a 5-6 piece kit...

They have “creatively” mapped 8 Waveforms to create a drum Kit that “behaves” like a normal instrument.

Listen to the 8Z sounds they are highly stylized and have plenty of thump for EDM use. They are using the architecture of a Normal 8 Element to fashion a uniquely controllable “Drum Kit”.

Using the power of the Normal Voice to create a “Kit”
Hope that helps.

Velocity Zones are available in the proper Drum Kits as the kicks, snares and hihats are typically multi-samples velocity wise.... if you are playing a drum groove using C1 kick, D1 or E1 snare, and F#1 hihats closed, you typically will get four or five different velocity switches as you play harder on those keys. The PwrStdKit1 (Power Standard Kit 1) the snare on D1 is a five-way Velocity swap, the hihats is a 4-way velocity swap, etc.,

On the MOXF and Motif (on which the MX is based) you get more detailed control over the Arpeggio playback in real-time. Via the so called “Arp Play FX”, if you are working with an MX and an external Sequencer you can play around with this response by increasing and decreasing the velocity of the triggering notes.