srodrigo Kawai's actions are the most realistic representations of acoustic actions
I don’t believe so. They feel light and nimble, making them ideal for extended practice sessions. Naturally, one’s initial impression of their quality is influenced by their low inertia, which feels great, a subconscious feeling that’s understandable. I’ve been impressed with the Kawai light actions for years too. However, I’ve also consistently encountered issues with their exaggerated dynamic response. It wasn’t until I started working on the Cybrid DIY project and understanding the physics of static and dynamic weight (inertia) more, when I realized that their actions are actually unrealistic, as absurd as it may sound to many.
The perception of weight in an action is a complex phenomenon, and it’s not always evident whether an action is comparable to the acoustic piano next to it. Acoustic pianos have a real escapement mechanism that fortunately eliminates the back pressure on your fingers when you release the keys. Nevertheless, they possess high inertia due to their relatively heavy hammers. Digital piano actions lack this real escapement, so they have two options: maintain the high hammer weight to replicate the high inertia of acoustic pianos and (unfortunately) retain the high back pressure, as Yamaha does. Alternatively, Kawai reduces the hammer weight, thereby decreasing the inertia of the keys, which naturally reduces the back pressure as well. At first glance, it might seem that the net effect of the Kawai action is that they are light and similar to the acoustic piano next to them. However, once you start playing more and demanding all the dynamics, you’ll quickly realize that on the Kawai, it’s too easy to accelerate the hammers and achieve high dynamics, while on the acoustic piano, you’ll have to exert significant effort.
srodrigo Yamaha's are the worst of the lot with unreasonable heavy actions and they seem fixated on carrying on with this
I understand this but I also think it's a common misconception, as I explained above.
Ultimately, the choice between Yamaha and Kawai actions comes down to personal preference. Some pianists prefer the realistic inertia of Yamaha actions, even at the cost of the constant back pressure, while others prefer the lighter and more nimble feel of Kawai actions. Neither option is inherently „better“ than the other.
Let's not say which digital piano action is more "realistic" because neither is 🙂 Only a real acoustic action in a real piano, or in a hybrid digital piano, is realistic.
