I'm quite happy with my CLP 170 and GH3 keyboard.

Usually I like the touch, even if a little heavy. But now I'm studying (try to... ) Schubert Impromptu op. 90 n 2 and I find the that weight is a limit in fast and light passages. Touch control to "light" doesn't help.

So, I wonder if GH3 is suitable for classical or there is something better. What are the opinions of PHAIII or RH3 owners in classical playing?

I agree, heavy actions can be an impediment to some playing. There happens to be a thread on this at the moment at
http://www.pianoworld.com/forum/ubbthreads.php/ubb/showflat/Number/1842681

I know these actions have their fans, and most DP actions have their shortcomings of one sort or another, and to some extent these things depends on what you're accustomed to and the demands of what you're playing, but that's why I disagree with posts which unequivocally say that some heavier feeling action is superior to some lighter feeling action. There are trade-offs...

I think PHAIII is significantly lighter than GH3 - but that's based on fairly brief experiments in a shop (I have Roland PHAII at home - also relatively light). My question to you would be about the Promega 3 - how does the action feel compared with GH3?

Promega 3 is a great keyboard!

But not suitable for classical playing as well. I felt the keyboard a good compromise of weight but suffers on quick note repetition. GH3 and its 3 sensors makes better job on this point.

Why do some posters say heavier actions are better?

What are the advantages and disadvantages of heavier actions and lighter actions?

Hmmm. For some reason all the light action advocates are coming out of the woodwork today.

I think super concert grands must actually be balanced lighter than the typical piano people play in homes and churches. Go to a piano store and play some acoustics, then a Yamaha digital, then a Roland digital and then back to the acoustic. I did this and found that the Roland felt much lighter than the acoustics and the Yamaha felt about right--of course various acoustics in the store felt different from each other, but sort of on average that was how I felt. Also I wouldn't say the Yamaha felt "like an acoustic," because there are differences, but the total work it takes to play was comparable.

The notion that GH/GH3 are heavier actions than acoustics seems questionable to me. Certainly they are heavier than some acoustics, but to me, not a typical acoustic. The downweight measurement in the other thread supporting this notion seems questionable, but even if it's spot on, downweight is by no means a reliable indicator of how "heavy" an action will feel when you play it. For example they might increase the downweight to compensate for a lighter moment of inertia so the overall impression of weight is about right.

If you want to know how heavier actions are better, go ahead a step further and play a semi-weighted keyboard and then report how good your experience is.

Now, I'm not saying heavier is always better. In fact I feel like my Kawai MP8 is too heavy, but it's substantially heavier than a Yamaha GH action, which I have also owned. (Kawai lightened their action up after the AWA PRO in my keyboard). Heavy actions feel very satisfying to play, and they allow easy pianissimo and legato. Not so great for a long practice session with a lot of bombastic notes. Also not so great for people liable to injure themselves.

Over time (since their invention) acoustic actions have gotten heavier and heaver for a variety of reasons. It may well be that the current acoustic de facto standard is heavier than is optimal, but I don't see evidence in the GH action of digitals really departing from the range of normal weights for acoustics.

As a side note, since there is a range of acceptable weights for acoustics, I think it is true that the GH and some other digital actions don't want to get too close to the light side because light actions are associated with cheapo digital keyboards, which are light to save money.

Roland's actions seem to be an exception and compare with the lightest acoustic actions. I suspect this may be because Roland has a different clientèle. It has an exceptionally strong presence among electronic musicians and near zero presence among classical musicians (since it makes no acoustics). Electronic musicians I can imagine being much more willing to depart from the feel of a typical acoustic in order to approach an ergonomic ideal. Stuffy acoustic sticklers who are dragged into digital pianos kicking and screaming will be afraid of their pianos feeling like cheap keyboards and gravitate toward known acoustic brands (Yamaha and Kawai) and keyboards with a more substantial feel. These also tend to be classical music people.

Maybe some day when acoustics are a rarity all digitals will gravitate toward some ergonomic ideal (which I imagine would be lighter than acoustics, not graded, and lacking letoff simulation).

A more fair minded and well considered appraisal of the matter than this ^ it would be difficult to imagine

Some "semi-weighted" boards feel worse than some "non-weighted" boards. The issue of how a key plays isn't strictly a matter of the weight. And "semi" doesn't simply mean "less weight than a fully-weighted" -- one thing they all seem to have in common the distribution of the weight seems different from a piano-style weighted action. That is, they don't simply feel like weighted actions except with less weight, they feel entirely different, the weight doesn't appear to be generated from the same place. (Semis can also feel quite different even from each other, for that matter.)

I think part of what you want from a keyboard, for playing piano, is some sense that you are causing something to strike something that creates a sound (even if that's an illusion), rather than simply pressing a key down, regardless of how heavy or light the key feels. You also want the key to return very quickly, yet not feel like it has a spring in it. Key touch is complicated, and weight is just one piece of it. Saying that I find lightly weighted piano actions more realistic (closer to the pianos I've played) than heavier ones does not mean that I think all light weighted actions feel good. There are all kinds of ways for actions to disappoint!

Very true. I wish there was an easier way to measure and report the meaningful characteristics of an action so we could discuss it easier and so it could be more easily standardized. I have always thought that travel length, upweight, downweight, and rotational inertia would be sufficient, but I'm not actually sure that's true. Of course, no one gives you rotational inertia numbers and it's hard to measure, so even these three would be hard to get. I guess at the end of the day we just have to go with our gut on these things.

Thanks for your contribution guys, but, please, stay in topic!

I'm not interested in haevy is better/worst than light action in general. I think it's a matter of personal flavour.

The point is: has any classical musician played fast and light passages on own digital piano with gratification (as would have played on a std piano)? In that case, what keyboard was it?

I think there are enough examples on youtube of fast classical pieces played on a digital piano.

Kawai CA13 (RM3)- Chopin Fantesie Impromptu
Yamaha Clavinova (probably GH3) - Chopin Etude Op.25 No.1

I'm sure you can find more videos from all digital piano brands. I think in a conservatory most of the practice pianos are uprights [with heavier action?] and yet the students do just fine.

I don't actually own a PHAIII action, but the people I know who use them indicate that they are perfect for this type of playing.

Got this from the V-Grand thread:

http://www.youtube.com/watch?v=w0-dC7eT_Oo

That's the same action found on heaps of Roland models.

Of course, it comes down to how good your technique is. There are dozens of videos of Jordan Rudess ripping it up on the Korg Kronos - an action which most people find to be deficient. Yet if you have enough technique up your sleeve, you can make it work.