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hi,

Just had this a couple of weeks but I have got a problem that certain notes or groups of notes make the metal grid that cover the speakers vibrate. It has got to the stage where I have to avoid playing those notes.

Anyone had any similar issues? I just thought I would ask before calling the dealer.

Apart form that the kawai is very well built and very easy to use especially compared to the casio PX350 I had.

I had this problem with my FP-7 which is why I went with a stage piano without on-board speakers. One thing that helped this is to fiddle with the EQ to find out which frequencies were the ones that resonated with the speakers and reduce just those frequencies a bit.

Another possible solution is to not use the on-board speakers and attach separate monitors.

Of course, the best solution is to talk with Kawai dealer and let them know this is an issue. I had waited too long to deal with my FP-7's problem and regretted that.

I had that problem with my first ES7. Drove me crazy as it was not a bad speaker but vibration to the right of the left speaker - especially noticeable playing D1. I brought it back to the dealer and fortunately he swapped it out with another new one without hesitation.

Also, look through this thread: http://www.pianoworld.com/forum/ubbthreads.php/topics/1973340/ES7%20speaker%20problems.html

Hello Nigel,



I'm sorry to that. I'm not sure what the cause is, but it obviously shouldn't happen. Definitely give your dealer a call and ask them to rectify the issue or provide a replacement.

Kind regards,
James
x

I had this problem with my Yamaha P250. It was actually caused by a resonance of the chassis. I found that simply loosening/tightening the screws made it go away. I can only assume this changed the boundary conditions for the reflections of the sound inside the piano. I had to play with it a bit to find just the right amount of play for it not to buzz, but after about an hour of fiddling with it I got it. It may not be the same thing in your situation, but it was such an easy fix it might be worth trying. Loosen the screws that hold the thing together a bit and see if it affects the quality of the buzzing. If you can affect it thusly, it might be just a matter of finding the right combination (loosening this screw, tightening that one) to make it go away completely.

Good Luck!

P.S. I can't imagine that loosening the screws as I suggested above would void the warranty, but check and make sure before you try. Maybe Kawai James can shed some light?

fizikisto, yes, I thought the same thing - one or two screws that just need to be tightened or loosened a little.

I had a similar problem years ago with some 70's Wharfedale speakers, whereby a particular bass frequency in a specific song would always cause a screw in one of the speakers to resonate. I eventually fixed it by looping the part of the song and checking each screw.

I'm not sure whether this would void the warranty (I personally doubt it), however it's probably best for musicman100 to take this issue up with the store and allow them to resolve the problem.

Cheers,
James
x

With my FP-7 I opened the thing up and tightening down every screw I saw, put in extra padding with some padded tape to provide for less vibrating with the case, all to no avail. Best to first get the instrument replaced since it's under warranty. Let them figure out what's wrong.

For what it's worth, my ES 7 has never had these vibrations, so it's not a universal design flaw.

Hi,

Thanks for all your replies.

I have only now got the problem sorted because of been away on holiday for 4 weeks. The supplier I got it from was in the end good at sorted at the problem.

After a few e-mails and waiting in a whole day for an engineer I complained and got a new one sent to me.

So far so good and no vibrating noise on the speakers BUT now I have another problem when I play F below middle C ( F3) and put the sustain pedal on I get feedback building up until I take the pedal off.Its like the speakers are distorting. The volume is set to about half way. It sound a bit like this problem

One thing that's for sure is that there are bugs in the way sustain is applied by the HI-XL engine: for instance if you play a note then apply the sustain pedal after a pause, the sound gets louder, which is obviously unrealistic and physically impossible. Also when you play certain notes repeatedly with sustain applied, the sound builds up into a cacophony, but with others it doesn't. I have screenshots of the WAV recordings on my CA95 showing this, and another thread confirmed it was still the case on the MP11. I have shared these findings with Kawai Europe but unfortunately I can't force them to do anything about it.

On this thread

http://www.pianoworld.com/forum/ubbthreads.php/topics/2315329/3.htmla


Any idea what I can do about it. It is a note I use quite often and is very annoying!!!

Thanks

Nigel, first off I'm glad the vibration has been fixed.

Regarding the sound characteristic on the 'F' note, does the same thing happen on neighbouring notes (e.g. E and F#)? If so, is the characteristic less prominent when reducing the Damper Resonance setting?

There is a certain phenomenon affecting one or two notes that we're currently investigating. I gather that my colleagues at Kawai Europe have been corresponding with lolatu to reduce the prominence of this characteristic.

Kind regards,
James
x

Hi James,

No only on that note at the moment. Also when I record the sound I don't think the same effect is recorded. Although I will try and experiment further with this. I will also try looking at the damper settings.

Apart from that I will love the look of the keyboard and the sound of it. It feels and sounds so much better then the casio PX350 I sent back.

Hello Nigel,



If you're recording to USB memory as a WAV or MP3 file, the sound is captured directly (digitally) from the tone generator. Actually, I believe even if you're recording to internal memory as a song, any such characteristics should also be captured and reproduced when played back.

Kind regards,
James
x

@musicman100: that's interesting that ES7 has the same problem. I thought it was just the HI-XL instruments, but it seems not. Yes it's the same note (F3) that sounds bad with the sustain pedal. There was a bunch of discussion in this thread about it... and some confusion as to the precise issue.

I thought at the time that it was CA95's soundboard that was suffering a physical resonance at this frequency. However, further testing involving sampling the sounds from F3 and surrounding notes, and changing the pitch up/down a semitone in Audacity, revealed that the problem is in the waveform itself. This is additionally visible on viewing a graphical representation. For some reason it doesn't sound so bad over headphones, or some CA95 speaker systems.

Here's one of the pictures I sent to Kawai, of a series of repeated notes. The Old / New thing is because they sent an update in which they toned down the damper resonance - however it didn't solve the problem. The important points from this picture are that

a) The F3 waveform explodes when you hold down the pedal
b) It doesn't happen with E3 (but - not illustrated here - it does to a lesser extent on F#3)
c) Damper resonance makes it worse, but the problem is there even with it turned off



I very much appreciate the time the Kawai people have spent replying to my emails, but their suggestions have mainly involved altering the EQ settings, and this doesn't help. I think the only person who can fix this probably lives in Japan and spends his days programming in C...


That almost sounds promising.

lolatu, if the characteristic on the 'F' note is indeed the same, it should be captured by the instrument's USB audio recorder, however Nigel previously suggested that this was not the case.

Nigel, are you able to provide a recording (using the ES7's USB audio recorder) of the note exhibiting this characteristic, please?

Cheers,
James
x

Hi,

I have done two recordings but they don't show the problem. However when I play them from the usb stick on the keyboard the problem happens.

the Budio shows the notes around F3

http://www.4shared.com/music/nwTNoao5ce/Audio-000.html
http://www.4shared.com/music/TZWg-0ffce/Budio-001.html

So it must be to do with the amp and speakers.

And yes James the problem does disappear when you put the Damper Resonance setting to off and gradually gets worse when you put it at 5.

Its strange that it only seems to affect that note ( not that I have tested all the notes yet!!!). that is the note that I notice the most.

Hi James why is the problem not recorded on the USB stick since it is a problem with damper resonance. Does that mean it is not recorded with the USB _ does that also mean string effects,etc are not recorded aswell?

Any body got any answers for this or does anyone else with an es7 has the same problem?

It sounds like a software problem to me since the other noted are not affected.

Nigel, I'm afraid I don't know, but the USB recorder is definitely recording the damper and string resonance etc.

This can be tested by creating recordings with those Virtual Technician parameters set to 0, then again to 10. The differences between the recording will be quite noticeable.

Kind regards,
James
x

Hi James,

Thanks for that. It is a real mystery where it is happening!! but very annoying. It must be the amp or speakers but why it just does it on the one note I don't know. I will try and do some further experiments to see if I can pin down the problem!! If not I might have to return the keyboard again!!!

Apart from that I am happy with the keyboard.

Thanks

I think these files (I assume they're recorded from the ES7's WAV recorder?) do show the problem. Well, they do when I listen to them. It seems easier to hear the problem over speakers - in my case, computer speakers, and also through the CA95. Not so much over headphones; perhaps it's just that headphones don't reproduce sound in the same way as speakers.

I downloaded your Budio file and looked at the waveform in Cubase:



F and F# seem to be louder, as is D# on the left channel (weird). We should be careful about drawing conclusions from this, as really we'd need to use the same MIDI clip with the same velocities on each note (which I have done separately).

So, yes it does seem to be the same problem in the ES7, and it's more audible over speakers than headphones, but it is there in the digital signal produced by the instrument.