How to Count Polyphony Motif XS

How to count POLYPHONY:
It is just not as easy as counting Elements to tell how much polyphony is used in a Voice. You have to determine how many Elements are actually making a sound at the same time. The Element is the basic component that makes up a VOICE. The Motif XS can use up to as many as 8 Elements to construct a VOICE. If an Element is stereo, it uses 2 notes of polyphony. Elements can be complex multi-sampled instruments with as many as 128 samples arranged in what are called “Keybanks” (see the manual for details of how samples are constructed and assembled into Elements).

A maximum of 2 samples can share the same Keybank - this accommodates stereo. A Keybank is defined by Note Range (horizontally) and Note Velocity Range (vertically) within an Element. Those are the important factors to consider.

Also to be considered in the XS-series is the XA CONTROL (Expanded Articulation Control). This can determine when/if an Element is to sound. For example, the XA Control setting for Element 8 on the Full Concert Grand requires that it only sound when notes are let go… it responds with a “Key Off” sample. Or, as we’ll see below, a group of Elements can be Muted and an entire orchestral bowed string section can be swapped for a pizzicato articulation. This is handled by switching which Elements are sounding.

And an Element only uses polyphony when it is actually sounding.

Take the Voice PRE4: 015(A15): Medium Large Section. If you press the EDIT button and view the active Elements you would assume this is a 7 Element Voice (and there is a stereo element in there). But if you conclude that it takes 14 notes of polyphony for each note played ...you would be WRONG. Way WRONG. It actually uses only a maximum of 2 notes of polyphony for every note struck.

Each of the Elements can be note limited as to key range and limited to respond to a specific range of key-on Velocity, or to only sound at Key Off, or only to sound when a particular “articulation” is required.

Let’s Explore:
While in EDIT you can MUTE and UNMUTE the Elements so that you isolate them one at a time and hear their individual contribution. (Use Track buttons 1 - 8 to SELECT Elements for viewing. Use track buttons 9, 10, 11, 12, 13, 14, 15 and 16 to MUTE OFF/ON Elements 1, 2, 3, 4, 5, 6, 7 and 8, respectively).

Element 1 = Key Range = C-2/G8 = Velocity Range = 1-74 [all AF Off]
Element 2 = Key Range = C-2/G8 = Velocity Range = 1-74 [all AF Off]
Element 3 = Key Range = C-2/G8 = Velocity Range = 75-109 [all AF Off]
Element 4 = Key Range = C-2/G8 = Velocity Range = 75-109 [all AF Off]
Element 5 = Key Range = C-2/G8 = Velocity Range = 110-127 [all AF Off]
Element 6 = Key Range = C-2/G8 = Velocity Range = 110-127 [all AF Off]
Element 7 = Key Range = C-2/G8 = Velocity Range = 1-127* [AF1 on]
Element 8 = not used…

*Used only when [AF1] is lit (this Element sounds alone as a “Large Stereo Pizzicato” wave is called up). That is when you press [AF1]; the first 6 Elements are muted and only Element 7 sounds.

You can learn what you need about a Voice’s polyphony by checking the Element’s OSCILLATOR page:
Press [EDIT]
Press Track [1] to select Element Edit parameters
Press [F1] OSCILLATOR

On this screen you can find out all about the tone source for an Element. You can determine if the wave is stereo or not… a suffix of “St” denotes stereo. In this particular string sound on Element 7 “Large Pizzicato St” is a stereo wave.

This particular string sound uses Element 1 and 2 as a L/R combination for low velocity (Element 1 is panned left and Element 2 is panned right). It uses Elements 3 and 4 as a L/R combination for medium velocity. And it uses Elements 5 and 6 as a L/R combination for hard velocity strikes.

Each of these first six Elements will sound under the following Xpanded Articulation Control conditions – when both [AF] buttons are OFF (not lit)

Just knowing how many elements are in a Voice doesn’t tell you its polyphony, not by itself. You have to know if they are indeed sounding simultaneously. If all this sounds very time consuming when you are looking to select a Voice, well, yes it is but included with your Motif XS is a handy chart that will tell you exactly how many Elements are required per note pressed.

In your Motif XS Data List booklet there is a very convenient VOICE LIST which will tell you the exact number of Elements that sound per key struck. You will find that only a handful of Voices actually use 8 Elements simultaneously (obviously those are best used for “live” performance and not when sequencing).

VOICE LIST with Element column

Use this handy chart when you are in danger of using more than 128 musicians (er, sounding elements) simultaneously. In the real world you’d have to pay each musician – which is the natural control against using too much polyphony. In synthesizers you must spend your polyphony wisely. You may find that knowing about the number of simultaneous Elements can help you pick an appropriate Voice to accomplish your musical goals.

Hope that helps