I have an idea to build a case for a piano controller to convert it into a stand-alone piano.
Multiway speaker drivers would fit very naturally into a piano-ish shape.
So it would look a little like this cosmetic case, except contain speakers and amps.
(Doesn't it just cry out for a woofer to fit in the curve, tweeter just where the treble notes should be?)
It could be built as a sealed box speaker, but a real piano is more like an open backed dipole I suspect.
That would partially null out the bass frequencies in the approximate plane of the cabinet.
Does this actually happen?
I've never jumped up and down at a piano recital to compare the sound. 😉
I am sure the polar response of a real concert piano has been studied, anyone have ideas or references?
David
Multiway speaker drivers would fit very naturally into a piano-ish shape.
So it would look a little like this cosmetic case, except contain speakers and amps.
(Doesn't it just cry out for a woofer to fit in the curve, tweeter just where the treble notes should be?)
It could be built as a sealed box speaker, but a real piano is more like an open backed dipole I suspect.
That would partially null out the bass frequencies in the approximate plane of the cabinet.
Does this actually happen?
I've never jumped up and down at a piano recital to compare the sound. 😉
I am sure the polar response of a real concert piano has been studied, anyone have ideas or references?
David
https://hal.archives-ouvertes.fr/hal-00811332/document
https://asa.scitation.org/doi/10.1121/1.394321
etc.
Quite a challenge! I would start by putting a regular 2-way speaker in the body pointing up against the hood. Then make it 3-way and use lots of EQ to make it sound "natural". Don't make it too difficult! Stereo signal should be summed to mono.
https://asa.scitation.org/doi/10.1121/1.394321
etc.
Quite a challenge! I would start by putting a regular 2-way speaker in the body pointing up against the hood. Then make it 3-way and use lots of EQ to make it sound "natural". Don't make it too difficult! Stereo signal should be summed to mono.
Thanks, but these show the modal behaviour of the sound board, I am curious to know what the sound field of the piano looks like.
If the soundboard is basically a dipole then I would expect there would be a null approximately in the plane of the soundboard.
But that's about where the audience listen, so it would surprise me if it's a major effect.
Maybe the floor bounce fills in the null?
And the lid presumably modifies the polar pattern too.
I do know there's lots of discussion about optimal microphone placement to record a piano.
But I have never seen a polar plot, despite photos of Kawai and Yamaha pianos in anechoic chambers.
Best wishes
David
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https://researchspace.auckland.ac.nz/handle/2292/1430
Modal analysis and sound level measurements of an upright piano has shown that the radiation from the case is at least 20 dB lower than the radiation from the soundboard, and therefore the case is not a significant determinant of piano tone.
Yes it's hard to find farfield measurements. Some info from recording guides
https://soundcraftpiano.com/recording-piano.html
Even this Finnish study doesn't include grand piano
https://users.aalto.fi/~ktlokki/Publs/patynen_aaua_2010.pdf
http://recordingology.com/events/hi...-a-grand-piano-the-effect-of-attack-velocity/
Modal analysis and sound level measurements of an upright piano has shown that the radiation from the case is at least 20 dB lower than the radiation from the soundboard, and therefore the case is not a significant determinant of piano tone.
Yes it's hard to find farfield measurements. Some info from recording guides
https://soundcraftpiano.com/recording-piano.html
Even this Finnish study doesn't include grand piano
https://users.aalto.fi/~ktlokki/Publs/patynen_aaua_2010.pdf
http://recordingology.com/events/hi...-a-grand-piano-the-effect-of-attack-velocity/
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You may want to look at what Yamaha did with their digital baby grand pianos. I worked with Tom Grant on a small jazz club system to augment the coverage of a digital grand back in the mid 2000s. The piano had multiple speakers throughout the top inside the lid and underneath it. I was surprised how good it sounded. You could tell they split up the samples of notes to come out of certain groups of speakers depending on which specific keys were played.
usa.yamaha.com/products/musical_instruments/pianos/clavinova/clp-665gp
usa.yamaha.com/products/musical_instruments/pianos/clavinova/clp-665gp
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The Soundcraft link confirms that there really is some null in the plane of the piano!
So maybe an open back/dipole speaker does makes sense, certainly easier to build and less mass.
The New Zealand paper is excellent, thanks.
Best wishes
David
I have looked at the Kawai DGP30 but the action isn't the best.
I will have a closer look at the Yamahas
Best wishes
David
Yamahas are said to be best... They use recorded sounds, dsp and vibration modelling, have an extra speaker in the body etc.
I don't play but I've spent quite much time listening to uprights and grands too. The sound is so complex that imititation task seem overwhelming.
https://usa.yamaha.com/products/musical_instruments/pianos/digital/index.html
Seems like most of studies are done with nearfield measurements only, like this one
https://www.mdpi.com/2076-3417/10/7/2333/htm
I don't play but I've spent quite much time listening to uprights and grands too. The sound is so complex that imititation task seem overwhelming.
https://usa.yamaha.com/products/musical_instruments/pianos/digital/index.html
Seems like most of studies are done with nearfield measurements only, like this one
https://www.mdpi.com/2076-3417/10/7/2333/htm
Im about to start new project - Hybrid piano.
Basicaly - normal piano sound board with transducers. Imho better chance to get piano sound. It will be smaller than normal upright - maybe i augment bass and treble with normal speakers. will see.
Sound engine will be Pianoteq.
Basicaly - normal piano sound board with transducers. Imho better chance to get piano sound. It will be smaller than normal upright - maybe i augment bass and treble with normal speakers. will see.
Sound engine will be Pianoteq.
A piano is one of the hardest, most complex to reproduce instruments. I use piano recordings alot to evaluate speakers. There are so many interactions going on mechanically which are just the tip of the iceberg. Uprights can be tricky just from the typical placement against the wall. I would say Yamaha and Kurzweil have some of the best sampled piano sounds available. Most of the pro session players use them both.
When I said the Kawai DGP30 action wasn't the best, I meant that it is only a middle level Kawai action.
I believe the top Kawai action is excellent, at least on a par with the Yamaha.
The Kawai and Yamaha hybrid actions are even better, of course, but about the same cost as a nice acoustic concert piano anyway.
So, this is close to what I have in mind.
Except with better bass speaker, look at that wasted opportunity on the left!
Best wishes
David
A piano soundboard is indeed sorta dipole. You can verify this by comparing the bass of an upright pushed up against the wall ... with it placed at right angles to the wall.
Grands are more complicated because of the case and top. Your guess is as good as any at HF 🙂
I think I've seen a IoA paper on the subject in my previous life which sorta said the above.
Grands are more complicated because of the case and top. Your guess is as good as any at HF 🙂
I think I've seen a IoA paper on the subject in my previous life which sorta said the above.
If I have the bass speaker on the left, in the obvious swell of the frame, and the tweeter on the left, where it fits nicely, then the normal crossover of the speakers will match the natural spatial distribution of an acoustic piano.
Not sure if I need a mid, I am more inclined to use one that I would on a normal speaker, more spatial spread is better here.
Best wishes
David
Hi Richard, haven't been in touch for a while, how are you?
So you think an open backed build with the speakers in a simple baffle would work?
Just seems kind of funny to have a bass null in the plane of the listeners ears.
I expect the sound at the players position would be fine.
I am tempted to add an additional monopole, for different phase connections and sounds.
Like a Fender Stratocaster!
Best wishes
David
Still a beach bum though with several old age complications catching up with me 🙂
Non est tantum facile. Don't forget, in a grand, there's another dipole in close proximity .. the reflection from the floor.
But the biggest caveat is that high quality digital pianos expect high quality speakers and its easier to make 'high quality box speakers'. Certainly the best piano in sunny Cooktown, a Yamaha Clavinova upright, is a conventional if fancy shaped 'box'. Much easier to arrange good sound in different conditions/directions.
If you used a 'simple baffle' you would need loadsa EQ to approximate what the 'digital piano' expected and you would have to decide what condition/direction you wanted the best sound.
So your original idea of a box with loadsa units under the lid of a 'grand' is as good as any and probably how the Clavinova grands are arranged. If anyone knows different, please speak out.
But think what happens when you want to play your grand with the lid closed.
Nice, I unretired for a while but maybe it's time to re-retire.
Yes, I had considered that, I assume it's a major contributor to the bass response in an acoustic grand.
I will have to have a bit of a look and check this myself, probably a better selection here than Cooktown😉
I could wear headphones?
Best wishes
David