Yamaha NU1X "loud note" fix seems to cause another problem

Hallo dear PianoClack members,

I discovered your forum as an alternative to pianoworld and thought I would share the problem I have with my new Yamaha NU1X, as some of you may be interested in this.

I copied and translated the description of the problem out of the Mail to my dealer:

While playing, I noticed that some tones that I play forte / fortissimo do not sound as expected, but quieter and more muffled, as if I had only played mezzo forte or even mezzopiano. This does not refer to specific individual keys, but can occur with all keys. At first I didn't think anything of it, but it became more and more annoying to me.

Today I tested it very systematically: I played several keys fortissimo one after the other. For example, the first two notes played sound as one would expect - but the ln the third key is much more muffled and quieter, so as I would have only played it mf. If I then play this key one or two more times, even with very high intensity, it only stays with mf instead of f / ff. If I now take a short break and start again, then the key that has just caused problems and did not want to be louder reacts normally as f / ff. If I then repeat the whole thing again with other keys, the next few keys sound again quite normally ff and suddenly dull / mf again.

I wanted to take a closer look at the MIDI outputs of the keys and connected the NU1X to my laptop with Pianoteq. The program allows me to see the MIDI output (between 0 and 127; the higher the louder) of the keys being played. And then I could observe the following: When I play a key f / ff the MIDI output is around 110-120. If, however, suddenly there is one key that is quieter, the MIDI output is much lower, at around 70, as if it were limited by the software. Since the sensors work with every key, and this problem can occur with every key, I assume a software-related problem.

Before the firmware update 2.10, the NU1X was affected with the so-called "loud note issue", where sometimes very loud notes suddenly appeared while playing. Examples of this can be found on youtube or forum.pianoworld. The cause of the problem was probably due to the fact that the NU1X only uses one key movement sensor, which does not work as precisely as three-sensor systems. The problem does not occur with the N1X / 2 / 3X or with the Kawai NV-5/10 with three (Kawai two) sensors incl. hammer sensor. After the problem was first denied by Yamaha, the "loud note issue" was "fixed" with the firmware update - apparently a kind of algorithm was added to the software to detect very loud MIDI velocities and reduce them to avoid the sudden occurrence of loud notes... I guess this mechanism contributes to the fact that the software in the Yamaha sometimes recognizes very high MIDI sensor velocities as "loud notes" and reduces them, which explains the sudden duller tones. Again: The problem does not relate to certain individual keys, which could then be assumed to be a fundamental fault in the sensor or the like, but affects all equally (or not).

Until I discovered this problem it was a fantastic instrument. But my impressions really make sense now in the retrospective, in some pieces where I had do play f/ff I sometimes had the feeling my strike didn't translate very well in a nice, loud, growling/piercing tone. I thought it was my playing and I have to adjust to the new instrument…

Today I visited the next big piano store in Berlin to test if this happens with their NU1X - it does! It seems to be a systematic error due to the "loud note issue" firmware-update "fix". The software/algorithm seems to detect intentional hard strikes sometimes (and way too often) as an unintentional "loud note" and lessen the MIDI-value, resulting in a too soft sound... But it's a false alarm. I can't believe it, how can Yamaha still produce and sell these pianos with this systematic error due to their non-sufficient one sensor system? And I can't believe how nobody has noticed this until now? It's less noticeable than a sudden out of place loud note of course, so for Yamaha this may seem to be a better "solution" than the loud note issue.

I will send it back - that the keyboard responds accurately to my input is the minimum requirement for any piano, and even my Roland FP-30 can do this.

Seems that there is no alternative to a NV-5S/10S or N1X, but they are much more expensive…

porco_rosso faulty firmware brought down Volkswagen, brought down Boeing, and now Yamaha!

That's one more reason not to own an NU1X.

They better not have used the single sensor design in their upcoming models.

porco_rosso
I’m on the road, so can’t elaborate now but I think what you describe makes perfect sense and is a sad consequence of the general design of that piano 😢

Welcome to the forum. You are one of the firsts to come here through a google search (was it a google search?).

I don't have a nu1x so I will fire up some ideas just for troubeshooting: your ff notes are done with fast or slow repetition? Do you think that the muffled notes occur when playing a key that has not yet completely stopped and may still be bouncing? Try to see if you find a pattern like "it occurs everytime I press a key at ff and the key is still halfway up", or "... when the key is bouncing after reaching the top". If you can pinpoint the exact conditions, maybe the engineers can fix it... But since you cannot access the sensor values (only the final midi output) your hands are tied. Alternatively, if you really pinpoint the cause, there may be an action regulation tht solves it (less/more rebound, faster/slower key reset, etc).

vagfilm Thank you! No, I didn't find with with google. I discovered the forum a few weeks ago when that ban thing at pianoworld happened. I think someone in the modartt forum mentioned it. I just didn't sign up until now.

I'm very sure it's a software/sensor issue, not a regulation issue (the action is regulated very well and even). The muffled notes also occur without repetition, for example when hitting a new, not already played note with ff intensity.

I was not saying that it was a regulation problem. I thought maybe it was a firmware problem related with the starting position of the key: if the key travel was less than expected, the firmware would translate your midi 110 into midi 70 to avoid a loud note. But if the problem can also occur at first strike, then it is as you suspect: either a sensor problem (not likely) or a consequence of the loud note safety firmware (very likely). Maybe CG has another clever idea...

porco_rosso I will send it back - that the keyboard responds accurately to my input is the minimum requirement for any piano, and even my Roland FP-30 can do this.

Good for you and thank you for sharing this fault for others to be aware of. Hopefully, Yamaha will be motivated to address this issue as more noise is made (pardon the pun) by owners and potential buyers.

God Bless,
David

If you do a factory reset, will that take you to the original firmware or the revised? Probably the revised... And can you flash the original firmware?

My guess is that Yamaha is using some AI to figure out how loud to make the sound, and that this AI is not infallible. But given that there has not been much criticism of the NU1X since the (presumed) AI was included in a software upgrade, I have a feeling that Yamaha is going to ignore this issue with a vengeance.

David B Yes, that was my intention.

vagfilm I am note sure. The NU1X was delivered with the newest 2.1 Firmware (that supposedly fixed the loud note issue). Now that I agreed with the dealer to return the NU1X I will not start to mess around with the firmware. But it really would be interesting to see if the "muffled ff note issue" (thats how I call it) disappears with the return of the "loud note issue" in an older firmware, as it would prove that this problem was introduced with the "loud note detection" algorithm in the 2.1 Firmware update.

QuasiUnaFantasia Unfortunately I think so too.

I am really frustrated. I decided for the NU1X after many months of testing all DPs from Yamaha, Kawai, Roland and Casio. Just to discover this.

I'm finally at my computer and can elaborate more.

It was me who first proposed a workaround to the loud note problem on the PW forum:

Since the issue happens when the key has not been released fully but just below the top position, the sensing logic assumes it has been released fully and will be ready to detect a repeated strike. However mechanically the jack has not been reengaged under the butt and the key is then very easy to be pushed with a high velocity (no weight to throw under your finger) and so the sensing logic is fooled into thinking this is a regular strike with a high velocity. So, my suggestion here is that this can happen in different situations. Of course one of them is to do it deliberately as I have demonstrated:

However it can also naturally happen in quick repetition, such as e.g. single key repetitions or trills when the key hasn't returned fully and you're pressing it again. And so for this particular case my proposal is for the sensing logic to detect the time between two or more activations of the same key (even if there is another note in between) and if one of the repeated strikes has a velocity higher than say 125 while the duration is shorter than a threshold (hence the repetition is quick), then assume this is the "loud note issue" happening, so then take the velocity from the first strike (or average it for multiple such strikes) and apply it to the "offending" one. This can work in many situations but unfortunately may affect genuinely loud strikes...

Anyway, a member on PW implemented my proposal (I forgot his name, wasn't that actually @xooorx ?) and published it on GitHub by just using a script interpreting the MIDI data, similar to @vagfilm MIDI filter. He said it was working OK for him and soon he was contacted by Yamaha and they provided him with a beta firmware that implemented the same logic for him to try. Later on they made it official and also created one for NU1 (but it's not published, people should ask Yamaha for it).

As has been discussed so many times, there's no easy solution to this problem if using only key sensors. I believe the only simple and good solution for Yamaha would be to add mechanical repetition springs as in https://pianoclack.com/forum/d/171-feurich-high-speed-kamm-upright-action

This way the key will repeat as a grand piano and the mechanical jamming won't occur in the first place.

porco_rosso (quoted) The cause of the problem was probably due to the fact that the NU1X only uses one key movement sensor, which does not work as precisely as three-sensor systems.

It is not pertinent to compare hybrid numbers of sensors with usual digital piano action. Alpha pianos has only 2 sensors (hammer pressure, damper), the N1X only 2 sensors (key position, hammer strike).

The issue is that there is nothing on a NU1X to measure if the escapement action has been rearmed and if we can play a sound.

The fact that 3 sensors on usual digital piano is enough deals with the absence of escapement.

Frédéric L The cause of the problem was probably due to the fact that the NU1X only uses one key movement sensor, which does not work as precisely as three-sensor systems.

This is not correct. Even if it is only one sensor, it is an optical sensor that is able to continuoulsy measure distances, and is used to calculate velocities between multiple distance points (how many, I am sure that Yamaha did not disclose). So, it should be, at least, as precise as a 3 sensor (if it calculates 3 distances) and has the potential to be much more precise if it calculates from more than 3 distances. And, if I remember correctly, Yamaha may use angular readings of the key rather than distances... but it boils down to the same principle. So, it is definitely not a "one sensor" system.

CyberGene the sensing logic assumes it has been released fully and will be ready to detect a repeated strike

But eddiepiano stated that he could create a muffled note by a single ff stroke, without repetition. So, if this is reproducible, it is note a jack issue. My bet is that at some fffff strikes, the Yamaha logic calculates very high velocities, and as a safety measure assumes that to be a "loud note issue" and puts the note at m... (you can hear Yamaha engineer say: "no, no, no... no pianist can play this hard... if it is this high speed it should be a misreading due to repetition, and in that case make it a midi 70 and he should be happy").

But my point is that the number of sensors is not the key factor. NU1X has 1 analog sensor which count for 3 (1 for the damper, 2 for the velocity), and the Alpha has a damper sensor (1?) and a hammer pressure which could count for 2 since it is analog and measure the velocity.

No the key point is the measure of hammer movement which should verify the hammer has been moved. A configuration : 1 key sensor (damper) and 2 hammer sensors (hammer, velocity) could be more pertinent than 3 sensors at the keys like the shaded gray flag of the NU1X can emulate.

Sorry Frédéric: I quoted eddie from your post and somehow the quote was atributed to you.

vagfilm But eddiepiano stated that he could create a muffled note by a single ff stroke, without repetition. So, if this is reproducible, it is note a jack issue.

Hmm, if Eddie really meant that a single fff note would be muffled without a recent prior strike for the same note, then something is very wrong with the Yamaha algorithms.

I had other problem with my NU1X which was ultimately the reason to return it: two of the keys in the middle consistently produced slightly higher velocities than the surrounding keys, which could be confirmed by pressing the keys together with an object and observing the MIDI velocities. I reported that to Yamaha and they sent me instructions on how to activate the key calibration procedure but it didn't help. Unfortunately the NU1X has its quirks. Luckily my N1X is perfect in that regard.

What puzzle me is that the N3 service manual (sorry it is the only Aventgrand Service Manual I have), has no procedure for calibration, only a « test » which verify if each threshold is at the good height. But if the test fails, we are out of luck.

Note : there are 4 thresholds…

Hey, thank you all for the answers and the clarification regarding the sensor systems!

CyberGene Hmm, if Eddie really meant that a single fff note would be muffled without a recent prior strike for the same note, then something is very wrong with the Yamaha algorithms.

Yes, I mean it like this. A f/ff/fff strike on a note can send the right MIDi value and sound like it's supposed to, but a f/ff/ff strike on the same note can also only send a MIDI value of 70ish and sound muffled. It can happen on any key and it can happen with or without repetition. But this disbalance between input and output only happens when striking the key hard in the f+ range, thats why I think the software/algorithm that "fixed" the loud note bug detects a supposedly "loud note" (false alarm) and softens it. It does not happen the other way around (making a softer input louder as as it is) nor are they any other irregularities with die MIDI output when playing vom ppp - mf, it's very precise. And it's also very precise in the f+ range when the algorithm isn't involved.

Today I practiced on my good old Roland FP-30 (+ Pianoteq) and it was a good feeling to get reliable sounds also in the high dynamic range… But I missed the real action and especially the escapement.

Eddiepiano,: So you saved $5grand? 😆 Or will you get something else?