[quotePost id=123825]On the web page for the Montage M8X it says this:

GEX also provides key repetition behavior typically found in grand pianos.

What are they referring to?

I can't find anything in the quick guide or operation manual that provides any info about 'key repetition'.[/quotePost]

A friend of mine had a vertical piano and I was
really surprised at the fact of not being able
to play a song I had made days before using
my Yamaha CVP-96 (still alive and well).: the keys on her piano not returning quickly enough for my next note...!!!!

Frankly, as my song was about catching a mouse, it was obviously on a quick tempo, presto; presto ma non troppo, hence my surprise..

So the reference to "key repetition behavior typically found in grand pianos" in the context of the Montage M8X is likely describing a feature or mechanism designed to mimic the behavior of the keys on a traditional acoustic grand piano.

In a traditional grand piano, when a key is pressed (struck by a pianist's finger), there is a mechanism that allows the key to quickly return to its original position, ready for another strike. This mechanism is called "key repetition." It enables rapid and repeated note playing, making it easier for pianists to play complex passages or trills.

Key repetition in grand pianos is achieved through a combination of mechanical engineering, including a unique design of the key lever, hammers, and springs. It's an important feature for achieving the responsiveness and playability that pianists expect from acoustic grand pianos.

The statement on the Montage M8X webpage suggests that the GEX (Grand Expression) feature in this keyboard provides a digital emulation of this key repetition behavior found in acoustic grand pianos. It likely means that when you play the Montage M8X keyboard, it's designed to provide a level of key repetition behavior that mimics the feel and response of playing a grand piano, making it easier for pianists to perform complex or rapid passages with authenticity and expressiveness.

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[quotePost id=123827]the key repetition rate in a grand piano is almost entirely due to gravity. the hammers hit up and fall back down.[/quotePost]

We have arrived at the meaning of GEX !!!!

The higher the latitude, the higher the gravity. hence tempo ceiling is increased.

Get your tempo upper limit finally gravity independent thanks to Montage M8x, where key repetition is granted and Gravity EXcluded.

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The keyboard action is one of my favorite subjects and I too would be very interested to learn more about the key repetition behavior and also what are the eventual differences to Montage 8. I'm not a trained pianist but some time ago I recorded (a rather bad..) version of the Flight of the Bumble Bee (Rimsky-Korsakov; transcr. by S. Rachmaninoff) which also has some repetition. I usually record classical piano pieces with my old beloved Korg SGProX which IMO has an awesome fast and expressive weighted action, but this I wanted to play with the superb Montage 8 keyboard with the result that IMO I could capture the repetitions etc. pretty well (at least I don't remember having any big problems with them). I think it goes to show that you can play almost anything with the Montage 8 keyboard. So it would be awesome to get my hands on the new M8X, and it would be great to see some reviews about the action.
-Vintage

[quotePost id=123829]... some time ago I recorded (a rather bad..) version of the Flight of the Bumble Bee ....
[/quotePost]

Don't say so...it is your own version. Enjoy !!!!

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Say we set tempo to 5 and then 300.

We place equipment on a key to repeat strikes.

We set speed to 10 strikes per second and record.

Will there be any difference when played
back or simply the names assigned to the notes will change from X to X/60 or from X to X×360 ?

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Hmm.. interesting. I'm not an expert on this, but with respect to the the physical keyboard, all I know is that I just tried to play some 16th notes on some single keys of the Montage 8 and I managed to play a few 16th notes in a row in the tempo of 260 bpm (FYI I played with both hands of course). So if I'm not wrong that would be 17.33 16th notes per second?

So it seems that the Montage 8 keyboard is already pretty fast and I think you can play pretty repetitive stuff with it, but you have to be pretty careful for it to succeed. On the other hand, I have to say that my old 1997 Korg SGProX weighted keyboard is also extremely fast in that respect. It would be awesome to learn more about the GEX in this regard. For example, are there some major physical changes that have been made to the keyboard action after the Montage 8 to enable a grand-piano-like repetition behavior? And does the new electromagnetic induction key sensor technology possibly play some role in this, or is it more related to the polyphonic aftertouch?

Typically this faster repetition is accomplished with 3 sensors. The typical synth action will have two sensors. One near the start of key travel and another one closer to the end of travel. The time it takes to trip both sensors determines velocity (which is aptly named).

The problem with this configuration is that if you don't lift the key all the way before striking again, you may never reach that first sensor and so no note will be registered.

3 sensors sticks a sensor between these extremes so you only have to let off the key "half way" in order for the keyboard to have two sensors (middle and end) in order to determine velocity.

The GEX is said to have more of a continuous system where I imagine three sensor or even different configurations can be simulated. I would imagine these key positions are scanned in a periodic fashion (i.e. polling).

The CP88 has 3 sensors which should provide slightly better performance than the Montage classic.

Jason's got it right (as usual). I'll just add a bit... it's not so much about "fast" repetition as it is about "soft" (or fast and soft) repetition. If you listen to the introduction of Billy Joel's "Angry Young Man," assuming you can play it at all, you can do it just fine on a 2-sensor board, because it is being played at high velocity, which means his fingers come way up between strikes, to achieve that velocity (in fact, he uses two hands). But if you were trying to do a much quieter repetition where you didn't want/need to lift your finger so high between strikes, a 2-sensor board will limit you. Trills are probably where this comes most into play.

Even 2-sensor boards can have their "top sensor" placed low enough that you can achieve much of this ability, or at least much more of it than on some other boards (I believe the Korg RH3 action falls into this category), though that also means their release point is low, so it alters another aspect of the way the board plays. Also, if you want to re-strike a note without silencing it first, and you don't have the damper pedal depressed, you would need that middle sensor to do that, as well... and a lower-than-average top sensor placement won't provide that 3-sensor ability.

3-sensor system boards can vary a lot in how high or low that middle sensor is placed. There's a video online comparing a 3-sensor Casio to a 3-sensor Kawai that illustrates this well. The middle sensor of the Casio is placed so high that it rarely provides much benefit, certainly compared to the Kawai. So it's one of those things where you can't just see the feature listed in a checkbox and assume the implementation is as good as it is on some other board. Kind of like aftertouch in that way... not all boards that have it implement it equally well.

Anyway, back to the topic at hand, yes, if the M8 sensor is optical/continuous, then it should be possible to support all of these kinds of behaviors, or even have the board's behavior in these respects vary depending on the patch. In theory. 🙂

Yeah, key repetition. Sorry, I was watching football yesterday (and playing out). 😀

These Youtube videos were posted on Piano World Forum (How a Grand Piano Works and How an Upright Works):

https://youtu.be/vFXBIFyG4tU
https://youtu.be/2kikWX2yOto

Nothing in the digital realm frightens me, but this mechanical stuff is voodoo. I will not try to explain actions and make a fool of myself. 😉 The acoustic/digital piano section of the Yamaha web site has good videos, too. If you can't get enough of this, please visit the piano fashionistas (fascistas?) on Piano World Forum. 😮

I'm shopping for an 88 something with an action that will help me transition to an acoustic grand when I need to fill in as pianist. In the end, I accept that key repetition is a thing and keep trying/comparing different digital pianos/keyboards.

BTW, "Grand Expression Modeling" is a Yamaha digital piano thing. It includes the software side of the sensor system and is part of the DP synthesis engine. For now, M8x only does PAT tricks.

All the best -- pj

This picture might help explain what other folks are saying about triple-sensor. I found this picture in a Yamaha training course that included GH3 actions.

Basically, triple-sensor detects only three discrete positions. The electromagnetic shutter system lets software track along the entire continuous key movement curve.

-- pj

Gentlemen, as usually, your posts have been very comprehensive and informative.

I think the developments they have done with the M8X keyboard seem pretty impressive. I would still like to ask however, does anybody know whether the actual keyboard mechanism of the M8X is or feels the same or different as the one in the Montage 8 (GEX v. balanced hammer mechanism)? I mean, apart from the fact that there now is the electromagnetic induction key sensor technology and PAT etc.

Also I'd like to know, does the M8X now have the escapement/double escapement system in the piano sounds?

I thought I'd post this question to this thread, since it is also related to the key repetition behavior.

-VK

Other reports indicate that the Montage M8x does feel different from the BHE in the Montage 8, lighter. (Which, to me, sounds like a good thing, and the reports I've read so far have been positive.) As for escapement, that's about feel, not sound (except to the extent that it affects note repetition, which is something that is supposed to have been enhanced in the GEX).

I haven't done much research into this, but I had thought that Yamaha's GEX approach was optical and not inductive/magnetic. I just base this of of the pictures that show LED lights and my thought was that there's a "flap" that will start to cover up an LED from an "optical sensor" on the other side of the "flap" (shutter) and the "optical sensor" changes resistance as a result. Greyscale is because what we're measuring is intensity of the LED as received by the "optical sensor" is not concerned of wavelength but rather amplitude so the "picture" this "optical sensor" receives and relays is only a greyscale representation of the source LED.

Here's Kawai's internals where you see the LED side of the equation:

What looks like an LED isn't really the light source. There's a light pipe connected to a fiber optic "line" that has refractive properties such that an LED's wavelengths are transmitted through the line and then are spread out to the light pipe. This gives slightly better mechanical control and also means that electronic components (at least on the transmit side) can stay on PCBs away from the key mechanics.

... so out of all of this description, I'm not sure what to make of the "magnetic" references. Open to learning.