Essentially the same vocoder effect (without as much options to edit the effect):

https://www.youtube.com/watch?v=SvojM_Qs3do

For choir, the general suggestion is to limit the bandwidth of the filter. This can likely be translated into the settings -- I don't have my keyboard setup to check it out.

Although not Yamaha - a really cool demo of the vocoder-choir thing:

https://www.youtube.com/watch?v=RBG8T2f3uBE

Also, there's a an article here:

http://www.easysounds.eu/MusicProductionGuide_2019_05_EN.pdf

That doesn't quite spell out the settings for a choir style vocoder - but does mention it. I reference the article because there is mention of promotional (free) content involving vocoders. Maybe it's still available and maybe there's something in there that's a better starting point than the few available presets. At least it would give you some chance to test-drive the wider full pack and see if there's enough goodness there to see what the full set is like. Or maybe just the promo material will guide you in the right direction without going any further. ... assuming it's available.

I'll try to wrap my post

I'm not an English speaker so, I would say sorry for that 😉 From my own experience:

Well if you're looking for a Roland VP-770 or some kind of board.

keep in mind the vocoder of the Montage is capable do about the same thing.

The vocoder itself sounds robotic but it's expressive, with a choir waveform as a carrier and finding a sweetspot between vocoder and waveform. The results can be promising but it needs a bit of tweaking to your own taste (bands, balancing vocoder and waveform) 🙂

Also the vocoder is tracking dynamics really well so volume swells and velocity yes it's all possible 😀 + I only have use it with just in 1 part with 1 element. So it's capable to do more 🙂

@Jason

Wow, this video you posted below is exactly what I am trying to do on the Montage using Choir voices, except my attempts make the Choir waveforms sound very mono & robotic, and not like a choir as is heard in this video. This is exactly what I am trying to figure out, but I don't know how the BPF Gains 1-8 should be set, nor what the Formant & other parameters should be to achieve the same type of Vocoder effect..!?

Although not Yamaha - a really cool demo of the vocoder-choir thing:
https://www.youtube.com/watch?v=RBG8T2f3uBE

I have emailed Easysounds as per the article you posted & hopefully something will come from that. I'm hoping someone can either give guidance on how the various parameters should be set to achieve a choir-like vocoder effect, or there is already a programmed performance that has the exact right settings to achieve this.

http://www.easysounds.eu/MusicProductionGuide_2019_05_EN.pdf

Thanks!

I am wondering if anyone has some experience with &/or knowledge of how the Montage's vocoder effect could be used (with a mic as the modulator - via AD Input), so that is sounds less like a robot, and more like actual singing/harmonies when using Choir Voices as the waveforms in the Elements of the PART?

I think you rather need an Harmonizer rather than a Vocoder.
In the video given by Jason, it's the Roland VP-550. It has different presets : Classical, Gospel, Pops, Male/Female, Vocoder. So the Vocoder is only one part. What we hear in the video is not the vocoder preset but the Gospel preset.
If you look for natural sounds, have a look to hamonizers.

Note I found a youtube demo of the easysounds set - nothing jumped out as being characteristically different than the presets. They sounded very similar.

In the video given by Jason, it's the Roland VP-550. It has different presets : Classical, Gospel, Pops, Male/Female, Vocoder. So the Vocoder is only one part. What we hear in the video is not the vocoder preset but the Gospel preset.
If you look for natural sounds, have a look to hamonizers.

Ah, so I might not quite be able to get the harmonizer type effect I was hoping for from a Montage via the Vocoder effect. Thanks for the info, I wouldn't have known that wasn't a vocoder part being used in the video & was a harmonizer...

Note I found a youtube demo of the easysounds set - nothing jumped out as being characteristically different than the presets. They sounded very similar.

I'll have to check out some YouTube vids of easysounds and the ones that are presets on the Montage. Hopefully there is one that is kinda close to what I'm trying to do...
It doesn't have to be perfect, but as close to a harmonizer as possible. There's an idea for a new effect ... if Yamaha could add a Harmonizer effect to the Montage that would be a nice gift. Meanwhile, I will work with what I have and tweak it.

If I burn 2 PARTs with Choir waveforms & the Vocoder effect, separating them by subtle detuning & panning L/R, I could potentially gain back the stereo, since the vocoder tends to make things sound more mono. I could use a chorus/stereoizer effect but after playing with the vocoder, it seems to needs some compression, so I was thinking of adding the 'VCM Compressor 376' as the second Insert B effect...

Also, I might do a comparison of the choir waveform sounds with the vocoder disabled, to it with the vocoder enabled, and then put it through a spectrum analyzer...maybe I can EQ it to be a bit closer to the original sound..!?

Here is another video with the great Roland VP 550 : Title https://www.youtube.com/watch?v=U51mdb9whRk