Topic by johng

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Topic: Midi velocity issue with Kawai CA65

I originally posted this issue on the Pianoworld forum but didn't get it resolved. Interested to know whether anyone has seen the same problem on this keyboard or other Kawai keyboards, for example the VPC1, and has any theories about why this occurs. Original posting from Pianoworld forum is reproduced below:

"I purchased a Kawai CA65 digital piano last year. I recently noticed there is a problem with several keys around middle C. There appears to be a ‘notch’ in the midi velocity response for certain keys, by which I mean that a certain range of midi velocities is not attainable.

For example, for middle C, if I hit the key repeatedly with gradually increasing force and monitor the midi velocities output, I observer that midi velocity values in the range approximately 47 to 55 are not attainable. In other words the velocity jumps from less than or equal to 47 to greater than or equal 55. However, midi velocity values below and above this range do occur. This behaviour is perfectly consistent for that particular key. The problem is annoying because it causes the affected keys to stand out when playing a run on the keyboard if the key velocities are in that range.

The range of missing values is not identical for all the affected keys, for example the low end of the range varies from 36 to 47 depending on the key.

I find it hard to imagine that the problem could have a mechanical cause. For example, I would expect a ‘sticky’ key might prevent low midi velocity values being achieved but would not lead to a gap in the middle of the velocity range. Before I contact Kawai support have any Kawai owners encountered a similar problem ?"

The full thread is at: http://www.pianoworld.com/forum/ubbthre...ost2281798

John

Reply by kalessin

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Re: Midi velocity issue with Kawai CA65

Hm. 47-55 is actually a very small range. This is about 6 percent of the full range; I doubt many people are actually capable of playing that precisely. You would probably need a robot to really make sure those velocities are really 'impossible'... or you are indeed a very skilled and advanced player with a heck of a lot more control than I have.

Be that as it may, I have never noticed anything like what you describe on my VPC-1, or on the MP-6 I had before the VPC. I have not checked every single key, but I have seen velocities of 50 and 52 on middle C in the MIDI log just now.

Last edited by kalessin (30-07-2014 20:45)
Pianoteq 6 Standard (Steinway D&B, Grotrian, Petrof, Steingraeber, Bechstein, Blüthner, K2, YC5, U4, Kremsegg 1&2, Karsten, Electric, Hohner)

Reply by johng

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Re: Midi velocity issue with Kawai CA65

kalessin wrote:

Hm. 47-55 is actually a very small range. This is about 6 percent of the full range; I doubt many people are actually capable of playing that precisely. You would probably need a robot to really make sure those velocities are really 'impossible'... or you are indeed a very skilled and advanced player with a heck of a lot more control than I have.

It may be a small range but it's sufficient to produce a noticeable change in timbre as well as volume when trying to play a run smoothly, causing that note to stand out. That's why I started investigating the issue. I don't claim to be able to accurately reproduce velocities within that range but by playing the same note a large number of times at different velocities and building up a histogram of velocities it is possible to confirm that the gap is there. This applies to about 6 of the keys out of the 88 on my CA65, and it is perfectly repeatable, i.e. if I try the test again I see the same few notes have a gap present.

Reply by kalessin

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Re: Midi velocity issue with Kawai CA65

Have you contacted Kawai?

Pianoteq 6 Standard (Steinway D&B, Grotrian, Petrof, Steingraeber, Bechstein, Blüthner, K2, YC5, U4, Kremsegg 1&2, Karsten, Electric, Hohner)

Reply by johng

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Re: Midi velocity issue with Kawai CA65

kalessin wrote:

Have you contacted Kawai?

I did send an email to Kawai Technical Support via a website about 3 months ago but didn't receive a reply. I can't now remember where I found the contact details. If you read through the pianoworld thread you will see that someone checked their own CA65 and found the same issue but on different keys. If they had found the issue on the same keys I would have suspected a firmware problem.

I circumvented the issue in the meantime by writing a bit of software to remap the midi velocities for those keys to close the gap. For example, if the gap is 47-55 I rescale velocities 56 to 127 to map onto the 47 to 127 range. The software then passes the modified messages onto Pianoteq via a virtual midi port. This isn't ideal but for now it seems to do the job. I may still follow it up with Kawai in future.

Reply by Cute James

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Re: Midi velocity issue with Kawai CA65

johng wrote:

I did send an email to Kawai Technical Support via a website about 3 months ago but didn't receive a reply.

Hello johng, I'm not sure why you did not receive a reply, but can only assume that your message was somehow lost in the system.

If you're willing to send me a PM with your email address, location (Country), and a copy of the email sent, I will attempt to forward it on to the relevant technical support staff.

Kind regards,
James
x

My mind says Kawai, but my heart says Nord.

Reply by johng

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Re: Midi velocity issue with Kawai CA65

Cute James wrote:

Hello johng, I'm not sure why you did not receive a reply, but can only assume that your message was somehow lost in the system.

If you're willing to send me a PM with your email address, location (Country), and a copy of the email sent, I will attempt to forward it on to the relevant technical support staff.

Hi James,

Thanks. I have sent you a PM.

John

Reply by rookie

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Re: Midi velocity issue with Kawai CA65

Hi John,

just to let you know: I tried to constantly hit the middle C at the velocity range you suggested, and I could not observe a gap. All values appear, within a rang of 45-55 - which I find hard enough to stay within (but I am a rookie).

Your solution is impressive to me. To program an intermediate MIDI-"plugin" to smoothen things is not exactly straight forward, in particular concerning latency I would imagine.

Cheers

rookie

johng wrote:

I originally posted this issue on the Pianoworld forum but didn't get it resolved. Interested to know whether anyone has seen the same problem on this keyboard or other Kawai keyboards, for example the VPC1, and has any theories about why this occurs. Original posting from Pianoworld forum is reproduced below:

"I purchased a Kawai CA65 digital piano last year. I recently noticed there is a problem with several keys around middle C. There appears to be a ‘notch’ in the midi velocity response for certain keys, by which I mean that a certain range of midi velocities is not attainable.

For example, for middle C, if I hit the key repeatedly with gradually increasing force and monitor the midi velocities output, I observer that midi velocity values in the range approximately 47 to 55 are not attainable. In other words the velocity jumps from less than or equal to 47 to greater than or equal 55. However, midi velocity values below and above this range do occur. This behaviour is perfectly consistent for that particular key. The problem is annoying because it causes the affected keys to stand out when playing a run on the keyboard if the key velocities are in that range.

The range of missing values is not identical for all the affected keys, for example the low end of the range varies from 36 to 47 depending on the key.

I find it hard to imagine that the problem could have a mechanical cause. For example, I would expect a ‘sticky’ key might prevent low midi velocity values being achieved but would not lead to a gap in the middle of the velocity range. Before I contact Kawai support have any Kawai owners encountered a similar problem ?"

The full thread is at: http://www.pianoworld.com/forum/ubbthre...ost2281798

John

Reply by johng

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Re: Midi velocity issue with Kawai CA65

rookie wrote:

Hi John,

just to let you know: I tried to constantly hit the middle C at the velocity range you suggested, and I could not observe a gap. All values appear, within a rang of 45-55 - which I find hard enough to stay within (but I am a rookie).

Your solution is impressive to me. To program an intermediate MIDI-"plugin" to smoothen things is not exactly straight forward, in particular concerning latency I would imagine.

Cheers

rookie

Thanks for checking this out. It certainly suggests the issue cannot be a firmware problem if the behaviour is not consistent across different CA65s. I don't know how prevalent the issue is. The person who responded on the pianoworld forum discovered the same issue on different keys but had not noticed the problem prior to seeing my posting. My problem has now been referred to Kawai Support, I will provide an update on this thread if there is any progress on resolution.

My 'solution' is really pretty simple (I have a software background). It's just a standalone program that reads  midi messages from the digital pianos's usb midi port, remaps the velocities, and outputs them to a virtual midi port created by a freeware program called loopMIDI. Pianoteq then receives the modified messages via the loopMidi port. There's no user interface, the mapping paramaters are hardcoded in the source code, so it's very specific to my setup. I haven't noticed any perceivable effect on latency but modern PCs are very fast and the code is not computationally intensive.

John