Data/Manual question MX61

[RRNY]

New here, so sorry if this is not the correct area to post this question. I have an MX61 and the data manual contains a column headed as "polyphony" along with the midi control codes for each patch. This column does not seem to represent the actual polyphony of the voice, does anyone know what it really means?

 

[SeaGtGruff]

It shows how many elements are used by the voice. Each element uses a tone generator, so each note you play with a given voice will use that number of tone generators. For example, every note you play with a voice that has 4 elements will be equivalent to playing 4 notes with a voice that has only 1 element, or 2 notes with a voice that has 2 elements, etc.

 

[RRNY]

Thank you, that makes sense. So it is not "polyphony" in the traditional sense, but rather how that particular voice contributes to the polyphony of the keyboard? Said differently, the sum of the tone generators used for all the voices across the channels cannot exceed some polyphonic value for the keyboard, right? The MX is advertised as 128-note polyphonic -- which would only be achievable if each voice in each part used a single tone generator? In reality, "note" polyphony would be potentially less than stated given many of the voices use more than one tone generator.

 

[SeaGtGruff]

That's correct, and there's often a comment at the beginning or end of the voice list stating that the actual number of notes that can be played at once depends on how many elements are used per voice, as well as whether 2 voices are layered together, etc.

The "maximum polyphony" represents how many inidividual tone generators the instrument has in all, and each tone generator can play 1 sound sample at any one time. Each voice element is a separate sound sample, so playing a voice that uses 2 elements is just like layering 2 single-element voices together.

So if you were playing only with voices that use 4 elements each, the maximum polyphony would essentially be reduced to 128/4=32 notes. Of course, most of the time you'll be playing with voices that use different numbers of elements, and some voices will be used for playing more notes than others-- e.g., a clarinet voice that's playing a monophonic line of melody, versus a piano voice that's playing a polyphonic part-- so the calculation isn't that simplistic.

 

[RRNY]

Outstanding. Thank you for the explanation.

 

[SeaGtGruff]

Someone on another keyboard forum once posted about how he tests the "real" polyphony of digital pianos and other keyboards (whether Yamaha, Casio, Korg, Roland, Nord, etc.) by banging the lowest key with sustain on, then going down the keys from higher to lower (with sustain still on) to see when the low note gets dropped. As I recall, he mentioned one model (not a Yamaha) that has a maximum polyphony of either 128 or 192 notes, and with the default acoustic grand piano voice the bass note got dropped after something like 24 high notes because of all the tone generators that went into playing a single note of that voice! I think piano voices are particularly prone to this sort of thing, because manufacturers generally use everything in their bag of tricks to make the piano voices sound as good as possible, which usually means combining a lot of elements or layers together.