Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards Presto: From a Kawai MP10 to a Yamaha AvantGrand N2...

Schooling TIME readers after having "just unwrapped the thing" and having "only had a few hours with the N2" is kind of a rash move IMO. We've owned the NX for going on a year now and I'm still not completely sure what I think about the piano sounds.

Well... the piece is headed, "First Impressions of Yamaha's N2...". That's kind of hard to misread.

Maybe you should try playing it? ;p

James
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James, Do you know the length of the MP-10 keys? What size of grand action is it intended to emulate?

kippesc, I'm afraid I cannot remember the key length off the top of my head. I have measured the keys in the past and posted the data here, but am unable to find the thread, unfortunately.

As for your second question, the 'RM3 Grand' action itself does not attempt to emulate any grand piano in particular.

Cheers,
James
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They are just under 13 inches long as measured in a picture on this thread.

Ah, well remembered.

James
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That was a very memorable thread for me. I keep thinking of opening up my MP8 and taking similar pictures for comparison but I'm not sure how much value added there will be...also I'm just a teeny bit scared that I might accidentally break something.

Someone needs to do a thorough AvantGrand nekid pictures thread so we can see some of the oft contested things like the true length of the keys (verify manufacturer claims), what's up with sensors on the hammers *and* the keys and the like.

gvfarns, Thanks. That Kawai thread is really surprising and interesting. It seems to me that the distance from the front of the key to the pivot point may be the most important dimension in determining the feel of an action because the mass on the back end of the lever (key) can be adjusted to accomodate varying leverage ratios. I may be wrong, though. I'm no engineer. In any event, compare the pivot point on the MP10 keys with the pivot point on a 7-foot (I think) Steingraeber (at 00:24) in the following video.

http://vimeo.com/21494671

Yeah, I've always kind of wondered about that. Your notion seems intuitive.

At the same time, I've always thought piano feel is about rotational inertia (and down-weight, but that's a simple thing). Rotational inertia seems like it would be the same whether created through weights or length. I may be wrong, though. Engineers?

I've been doing some investigations into this for my own edification and really need to do a post on it.

A key is a lever, and levers rotating over small angles can be linearized without too much error, which means (to a first order) we can dispense with moments and the like. So imagine a key as a lever with a mass counterweight on the other end.

Accelerating the mass takes a force, which is felt through the lever. Mass also exerts a return force due to gravity, but the acceleration of a mass by gravity is independent of the mass itself, so this means the return time of the key is purely a function of the square root of the leverage ratio and not at all on the mass, which is kind of surprising (at least it was to me initially).

Long story short, you can make the key feel "heavier" by either increasing the mass counterweight or the leverage ratio, but the return time will slow down if you increase the leverage ratio.

So for portability you want little counterweights geared up through large ratios, but that means the keys return more slowly. But since the return time is related to the square root of the leverage ratio, you can play with the leverage somewhat without significantly impacting the return time. However, I believe "sluggish" DP keys have counterweights that are too small coupled to leverage ratios that are too high.

Also, the density of the key itself isn't very important, which is also a bit surprising, though for portability you generally want to keep it low.

Kapish?

I like your summary, Dewster, but I wouldn't dispense with the role of momentum of the key system (key + hammers/weights/counterweights). Counterbalancing what is on either side of the pivot point on the lever has a certain effect on the perception of key weight (touch weight) but I think equally so, if not more, so is the rotational mass of the whole system. In short, how hard is it for the key to stop and change direction? If the rotational mass is high, it will be hard to play a note, release it and then play it again. Similarly when you press a key and it bottoms out, the felts on the keybed have to absorb the momentum before gravity or springs are able to send the key in the opposite direction. I think this is why a keyboard can feel relatively easy to play a few chords on, but the faster you play, the more the effect of rotational mass will become apparent - it's the effort to are expending into stopping and starting a mass. I have such a keyboard in my old Korg T1 - it's easier to press down and hold than my acoustic piano, but to play for longer periods, and to play faster it is quite exhausting.

My piano has a heavier touch weight, but is more agile with direction changes. For this reason, a good action with needs both aspects to feel pleasing to the player. I think this is a big part of what we are affected by when we try different DPs. They all have their own formula with regard to key length, mass, leverage, rotational mass, materials, etc. The formula also plays a big role in how expressive we feel we can be with a given action. We need to feel that we get reward for every physical effort we make and that we aren't expending effort just fighting against a resistant mechanism.

Interesting discussion.

Yes, I agree entirely, I was trying to keep my response here short and hopefully sweet. I'll do a full independent post soon.

Real piano actions often have counterbalance weights in the played ends of the keys, presumably to reduce the static downward force necessary to hold the note after being played, but this increases the mass that must be accelerated when the note is played quickly. It also increases the return time of the key, making it more sluggish that way.

DP keys generally don't need counterbalance weights on the played ends of the keys because the mass on the other end isn't really doing anything practical. So the designer can independently vary the key return time via the ratio, and the static weight via the mass & ratio.

Great analysis. Only here's the question: how (if at all) does this analysis support the notion that longer keys are better? For example, wouldn't the 9 foot grand keyboard feel more sluggish than the baby grand? And the baby grand more sluggish than the MP10? According to what I read here, it seems like piano designers (at least, acoustic piano designers) would be trying to minimize key length. I guess maybe they do that, subject to making the hammer hit in the optimal place.

So we should be happy that the smaller grand action was used in the AvantGrands, rather than the concert action?

Leverage is a ratio. Imagine a teeter-totter constructed in the usual way from a single board and pivot located in the very center. A weight on one end will the be felt 1:1 on the other end. It doesn't matter how large the actual board is if the leverage is 1:1 and you only press on the end.


Just the opposite. As Kippesc brought up above, the distance from the front of the key to the pivot point dictates how much the leverage ratio varies as you play closer to the end of the key or closer to the pivot point. Keys with more distance here ("longer keys" I suppose) will have less variation in this respect, which most would likely argue is a good thing, as the touch will vary less depending on where on the key you play. Thus, the revelation that the AG has the keys of a small grand rather than the nine foot CFIIIS as implied by Yamaha's press release likely isn't good news.

The full title of the article is "Piano or Pretender? First Impressions of Yamaha's AvantGrand N2". Even a quick first impression could easily reveal the audible looping on the low notes if one were looking for immediate evidence that the AG somehow fails in the complete realism department. Real pianos don't loop. Call me a serious nitpicker, but for me it's a pretender because you can't use it for critical intimate recording - though by most accounts a very well done one as these things go. In conclusion, Chick Corea and Glenn Gould something something.

Ahh. I hadn't been thinking about how hard it is to play at the front of the key vs the back. Good reason to have long keys. Thanks for that explanation.

You are a SERIOUS nitpicker!

OK, now back to your short-keyed, mechanically-disadvantaged, recording-challenged, 438 lb, £8000, quadraphonic looper!

Hello,
this is indeed interesting intuitive idea. I think you are right, since perhaps the action "feel" is also partly formed by consistency in between different fingers. I'll explain: more longer keys you get, you get longer distance from key top to the turning point and the ratio between distance of turning point to end of the key as you see it from the top of the keyboard and distance from the turning point to the top of the key, so this ratio is higher if you do have longer keys. Man's hands are curved and you can see a lot of people naturally playing not with fingers in the row, but forming an arc on the keyboard. This means some fingers need to press with more power (those longer fingers which are usually nearer to the turning point) then others (short fingers which are just playing on top of the keys and so their distance to turning point is longest). So from this it looks like the "feel" of action might also depend on this consistency of required press weight and this purely depends on the length of the keys from their top to the turning point. Longer the distance, better should be the "feel" -- at least from this point of view.
There are also another aspects like key's weight, their inertia etc, which all combined together make the actual man feel of the action. Also there is a possibility that some of us put higher priority on some of the action property (e.g. key length and hence consistency in weight in between fingers) while others put more priority on another property of the action....
This all is so interesting indeed...
Karel