Upright piano speaker simulator addon idea

dore_m The main reason I have a grand is because I grew up having the sound of the piano coming up at me from in front of me.

Well, these foam things are said to be not as pin-pointable as sound source in space as speakers are, so it's still something to try and would not cost much to experiment: hanging some fishing line from the piano beams underneath to hold it as close to them as possible without touching (which would cause buzzing). Alternatively, you can hang the foam thing from the ceiling, or make wall panel or… really part of the beauty of this design is that's it is so flexible that you can do everything with it. Not saying that everything will work "just fine", but you have many many things that are very easy to try and see how it goes -- compare that with even a bookshelf speaker, not to mention a largish floorstand one and how much work would be needed to simply test "how would it sound if I hang it on the ceiling where I think is the best position for sound to come from and I have all that cubic footage available?"

dore_m I guess the only ideal solution is to do what you're doing. Make another one!

That will work too, but you do need some square footage for that. Not much, but you said you don't have it…

Actually after I wrote that I realized that I could literally put a large one beneath the piano on the floor radiating upward, and put one on the piano lid. So when i'd want to play, I would just close the piano lid and the speaker would be right there radiating upward.

I have heard the sound of those types of speakers (but in the distant past). The sound is more diffuse, and more like a soundboard, but as you already figured out, it will take some experimentation to get the timbre to match. But having the diffuse sound actually is the novel part that cannot be reproduced that well with commercial speakers - so I think it's the right direction.

So one experiment, if you get to it first, will be to see how well the speakers radiate in a horizontal position. I'm wondering if the mass of the exciter will greatly affect the panel vibration in that direction.

dore_m So one experiment, if you get to it first, will be to see how well the speakers radiate in a horizontal position. I'm wondering if the mass of the exciter will greatly affect the panel vibration in that direction.

I am not interested in that use case myself, but the test won't cost me much (just hanging the panel somewhere horizontally) so that's a great idea for me to test that too.

dore_m Actually after I wrote that I realized that I could literally put a large one beneath the piano on the floor radiating upward, and put one on the piano lid. So when i'd want to play, I would just close the piano lid and the speaker would be right there radiating upward.

I believe that would be tricy because if those panels touch static objects such as the floor or the piano lid, buzzing is guaranteed. But you can still hang it from the bottom of the piano to almost the floor… of course you can attach the back of the exciter as he showed in the follow-up video (even though he was doing so horizontally)

RIP I believe that would be tricy because if those panels touch static objects such as the floor or the piano lid, buzzing is guaranteed.

Yeah, you're right. Seems more tricky than I expected. The upright piano idea probably is easier, but just not my personal end goal.

So after forgetting about this discussion for awhile, I just decided to buy some Dayton Audio transducers during Black Friday because I was planning on doing some experiments next year - most are on backorder, unless you want to pay a premium. I just decided to plan early and order early.

As luck would have it, two came in today, and I spent about an hour playing around with them. I first just put them on cardboard, and they sounded ok. Then I put it on the face of my Cajon and because the material was smaller in size and wood, it had less higher frequencies (or maybe because the edges of the surface were constrained). About that point, I realized that I could just push them up against the bottom of my piano's soundboard to see what they sound like. I definitely wasn't going to use the permanent tape.

Anyway, surprise, surprise….. Sounds alot like a Yamaha Transacoustic. I may have to do some recordings of the piano and the transducer/speaker to get some frequency spectrums to decide what to do next. The good news is that even though the position of the transducer can roughly be heard, the sound does project more like a piano than a cone speaker. If I position multiple transducers strategically underneath the soundboard, possibly along the bridge, the sound radiation will probably feel like a real piano, Now, if I can get the correct frequency spectrum so it also SOUNDS like a different piano, then I can play a Fazioli on my Mason & Hamlin, and actually have it sound and feel that way. Is it a pipe dream? At about $20/transducer its fun to try.

Do you want to compete with Resonance : https://resonancepiano.com/en/ ?

dore_m Now, if I can get the correct frequency spectrum so it also SOUNDS like a different piano, then I can play a Fazioli on my Mason & Hamlin, and actually have it sound and feel that way. Is it a pipe dream? At about $20/transducer its fun to try.

I tried that with my former grand, without being too "aggressive" in my quest. So my conclusion was simply: too much work to make it worth my time for me. Well, that was a 4' grand, and my main objective was to try to make the virtual instruments sound more "woody" (a shift in timbre), which they didn't.

The biggest problem which I encourage you to study is the attach-detach problem. The guys in the links above used sharp knives to detach and new strong adhesive tape to reattach (I communicated privately with them about it). But hey, at worse they would trash a $20 toy and some even cheaper pieces of scrap material: you don't want to do that with your soundboard. You may put an intermediate layer (e.g. the ole fashioned transparent plastic used for the real "slide projections") strongly attached to the transducer. Then use some other approach to attach that to the soundboard in a way that's sturdy enough to hold and not fall (and transmit the sound well and not buzz), while being easy to non-destructively removed. Please share if you find an ideal solution for this!

RIP The biggest problem which I encourage you to study is the attach-detach problem.

I played with it more last night and I think there isn't a good way to get the sound to come close to the timbre of another real piano. I might keep trying with a hybrid approach of soundboard + speakers near the hammers. I feel that the big players (Yamaha, etc) would have already done something like this if it were simple, but they probably wouldn't do such user unfriendly things like manual attach/detach methods, or 10 transducers, or something crazy that I might personally put up with.

If the soundboard thing works (and I'm not that hopeful), I'd probably just design a lever mechanism attached to the bottom of the piano structure where I can shift a lever and couple the transducer to the soundboard. It's not ideal, but so far I haven't heard much difference in sound quality when I just hold the transducer on with different pressures. I'm using a mic stand and a shockmount, which is basically a spring. Don't know how this added spring/mechanism will affect the sound.

Last night I also just put the transducer on a cardboard box and laid it on top of the piano. The frequency range was better, so I still may continue with this scheme of tuning a large speaker (2x4 feet) and placing on top of the piano lid. Still experimenting with whether or not the soundstage is similar to the real thing.

Frédéric L Do you want to compete with Resonance : https://resonancepiano.com/en/ ?

Interesting. Not trying to compete. I don't have any interest in making money from this, just an interest in trying to DIY a system that is really good for personal satisfaction. Thanks for the link, I may learn something…

Why don't you just buy a pink foam insulation sheet at the local hardware store, like that used in the Newer Hampshire TechIngredients videos?

That cheap foam will be easy to mount and move around transducers and you can ignore any foam damage.

I seem to recall the TechIngredients video illustrated the basic impact of moving the transducers around and adding more transducers with sand. That might provide some basic transducer guidelines for this application.

You can cut the foam roughly shaped to your piano using a saw or maybe a heated metal string. Then mount the foam behind the piano. If you were using a M&H grand piano, for example, rather than hang the foam from the bottom of the piano just cut some wood straps for legs like a table; the legs may have some audio impact (positive and negative) but are good enough for testing and you could move them around.

Take my comment (like all my other comments...) with a large grain of salt, because I really have no idea about soundboards and transducers, but in my naivete I would assume that the wood soundboard will have a large filtering effect upon the higher frequencies (which are easily dampened because a large piece of wood will not be the best medium to propagate high frequency vibrations). The piano sound (recorded by microphones) is already the result of that filtering. If that filtered sound is "injected" again in a soundboard it will go through a second cycle of filtering... My point being that probably the signal to input to the transducers would need to be enhanced in the high frequencies in order to the final result to be realistic. Maybe Pianoteq is in fact the best option for a transducer system because the higher harmonics can be enhanced. Is this the reason why hybrid systems have both speakers (for mid-high frequencies) and transducers (for good spatial spread)? Does this make sense?

n-player Why don't you just buy a pink foam insulation sheet at the local hardware store,

That is essentially what I was planning to do originally - try out different materials like this. But when I just put the transducer on top of a cardboard box without adhesive, I realized that I could easily try it on the soundboard for fun. I haven't experimented too much with it, but IF the soundboard could project the sound, this would be the ideal solution because the sound would project up and down at the same time. Using additional substrates like foam on top, around, behind, underneath the piano will, I think, give a different image. For example, putting the panel above the lid will allow sound to project up like a real piano, but not beneath to the floor as the piano is in the way. Also, the panel will also project downward and reflect off of the lid, which may cause some issues. Again, I'm just theorizing here.

BTW, good to see you here n-player.

@vagfim You're right, I was just intending to EQ the hell out of the signal to see if I could get anything near close. But I think the additional substrate, like foam, will be easier to control and tune. I dont have access to every part of the soundboard because of the piano's structure underneath, but it might be fun to try anyway to see where it leads. Too many projects to fiddle with…

I also speak from a layman’s perspective, but I believe Steingraeber has been working on a ‘hybrid’ using only a full soundboard, and they have chosen Pianoteq (perhaps for the reasons mentioned by vagfilm); but still, the good news is that some piano makers (not Steinway) are working on these type of instruments and hopefully it’ll just be a matter of time before we see a hybrid with a full soundboard and no speakers whatsoever.

We’ve been waiting on Kawai to do this, but maybe they will be beaten to it by Steingraeber or some other piano maker.

P.S.

I know that some believe that a ‘soundboard’ for a digital is a gimmick, and that speakers alone can do the job, but I humbly disagree, once again, from a layman’s perspective.

Pete14 I know that some believe that a ‘soundboard’ for a digital is a gimmick, and that speakers alone can do the job, but I humbly disagree, once again, from a layman’s perspective.

I can neither agree nor disagree. I've heard virtual instruments played through various speakers that were good, bad, or in between. But I've never heard one played through a soundboard.

Yes, I've heard the Kawai CA- series pianos, which play through a combination of speakers and soundboard ... but the samples in those pianos are not top notch. And I did not notice any mode setting for "soundboard only".

So who's to say that a virtual instrument with only a soundboard will produce acceptable results?
And who would think it would be acceptable when driven by Pianoteq?

Pete14

We’ve been waiting on Kawai to do this

Kawai Aures is doing exactly that. No speakers, just a soundboard with some transducers:

Soundboard Speaker System with 4 transducers (Low-Mid Range × 2, High Range × 2)

Yes, that’s true, but I’m hoping for ‘pure digital’ with a soundboard and no speakers (NV-20).

The Trans/Aures comes attached to a full acoustic, strings and all, and I don’t want to pay for all that stuff. Now, I do understand how for those wanting to have the silent capability for late-night practice whilst also having a full acoustic for ‘the day’ something like the Trans-Aures would be appealing.

MHirsch Kawai Aures is doing exactly that.

Yes, you are correct: I was forgetting the Aures line... And for some reason I don't think that Kawai is using different samples in those transducers. So maybe a soundboard is truly a good medium for full-range transmission. Like I said, this was unsubstantiated bias...

So that was why I was trying to distinguish between the sound projection (unlike a cone speaker) and the timbre. I tried a Yamaha transacoustic once, and wasn't impressed by the timbre that the speaker put out, but did like the way it projected like a piano soundboard (as it was using the piano soundboard).

With fine tuning, I might be able to achieve something like this:

But still, I don't feel the sound is good enough. But possibly a "hybrid" using the piano soundboard and some separate tweeters and a subwoofer placed in the correct places. Maybe. Or just the foam substrates instead. Dunno yet.

Pete14

But Pete, what makes you think it’ll be a lot cheaper? NV10s, a pretty much acoustic instrument without strings and all, is already at the same price level as a K300 with an Aures system. To me, where’s no point in buying an almost acoustic piano but not really acoustic, and not really cheaper.

The only reason to even look at NV10s for me was the action - but its sound was let’s say less convincing than the sound of a K300 (no Aures) standing next to it. K300 is 3.3k € cheaper, by the way.

vagfilm

Well, I played a K500 Aures.

It’s acoustic sound, compared to the digital, was a whole lot better - natural, powerful but still mellow. Digital sounded like there’s a much bigger piano inside, trying to get out. I was not impressed like at all.

That’s been a year ago, things might have changed with Aures2, but there’ll be Aures3 - better, more natural and authentic, <marketing stuff>. And then what, an endless upgrade loop?