Topic: Adding a Transducer to a piano's Soundboard

Does anyone here have experience adding a transducer (or several) to a piano's soundboard?  It seems like this might be the purest way to have Pianoteq working in a "Player" capacity, similar to that of a Yamaha TransAcoustic or a Kawai hybrid.  I am contemplating such a project.

Here are some 'teaser videos':

https://www.youtube.com/watch?v=NTfl7o5xbyI   - an audio speaker made of spruce, as a type of alternative musical speaker

https://www.youtube.com/watch?v=TXmY9Oi2DXA   - David Pogue's review of the Yamaha U1 TransAcoustic

https://www.parts-express.com/resources...e-exciters  -  A parts company's page with videos on using transducers/exciters

http://www.denismusique.com/en/yamaha-u...lent-ta-pe  An interesting page showing how Yamaha doesn't stick stick transducers on the soundboard (as I was considering doing... hmm..?)

- David

Re: Adding a Transducer to a piano's Soundboard

Cool.  With cream on top.

The spruce speakers are interesting (and would also probably get me evicted, alas - somehow I think all that resonance would go down badly with everyone else !).

I'm not sure if Pianoteq sound models actually would work on this idea.  Wouldn't they need an actual transducer model in the sound system (instead of mics) to get the required output ?  Which incidentally might be an interesting idea for the next version.

OK, given the choice of spruce speaker or hybrid piano I'm going to vote for ... that woman's voice.  I could listen to that for hours and not notice a single word or much else.  :-)

StephenG

Re: Adding a Transducer to a piano's Soundboard

Cool, I'm glad you posted!

I've been experimenting with a set of transducers. I'm a complete neophyte, so I've been learning from scratch. My first impulse was to use an actual piano soundboard but I'm realizing that a soundboard for a digital pianos should have a different design.


WEIGHT
We can use a very light/thin soundboards, like the ones we see on violins, guitars, drum heads and flat panel speakers. We don't need to support the weight of a piano frame and strings.


MATERIALS
The main principle seems to be a high strength-to-weight ratio - as light as possible and as strong as possible. High-quality tonewood is the traditional material , but I've gotten decent results with 3x3 aluminum sheets, foam board panels, drum heads, guitars and cajons.

Someone pointed out to me that 'wood is also carbon fiber', which I thought was funny. So I'm curious to see if a DIY carbon fiber board will work.

In high-quality tonewood, the fiber is lined up in parallel and also tightly packed together. The problem with most commercially available carbon fiber plate is that the fiber is woven together at 90 degree angles, but I think laying carbon fibers more like the grain of high-quality tonewood will work. My summer project will be to turn some unidirectional carbon fiber into a soundboard. A side note, Phoenix Piano carbon fiber soundboards also use unidirectional fiber carbon as opposed to woven carbon fiber.


SHAPE
The shape of traditional soundboards seems to be mostly functional with only a small nod to acoustics. For example, piano soundboards get their shape mostly from the piano frame while guitar & violin soundboards are shaped to be easy to hold.

But I was stumped for figuring out a shape because I know nothing about soundboard design. I decided a plain old circle would work the best (see videos below). You can see that the sound waves on a circular plate sound waves are clear and closer to traditional speaker design. I figure a 4-foot circle to start to get decent treble/bass response and if it works, build a 6-foot one. (there's also a question -  orient horizontally like a grand piano or vertically like an upright).



Circular Chladni plate
https://www.youtube.com/watch?v=CGiiSlMFFlI

Rectangular Chladni plate
https://www.youtube.com/watch?v=1yaqUI4b974

Last edited by Groove On (16-04-2018 09:24)

Re: Adding a Transducer to a piano's Soundboard

Very interesting, especially about the theoretical driver design.  Circular is likely the most elegant, and most speaker manufacturers do this.  I wonder if Magnepans and Quad ESLs and other planar manufacturers have difficulties at the corners with materials and edge attachment. 

I will follow your progress with the creation of the best driver, while I am most interested in learning how to best drive the 'speaker' that I have - mainly my upright piano's soundboard.

What can you add about driver size, power demands, attachments, etc.?

- David

- David

Re: Adding a Transducer to a piano's Soundboard

On some digitals you can adjust soundboard behaviour; it's effect is built in which is variable.  I invariably turn it to zero.  I would hate a piano to sound like it had a soundboard . . .

I'm playing all the right notes but not necessarily in the right order

Re: Adding a Transducer to a piano's Soundboard

While somewhat cool, I don't find that initial spruce speaker to be all that great.  It certainly is not linear through the audio spectrum.  What it does do well is give the feeling of something physically moving.  Most acoustic pianos do use a soundboard that vibrates, but that isn't the only thing making sound.  The strings are vibrating too.

One of the projects I've considered is putting a bass shaker, or another exciter attached to the piano bench, not to create sound, but to transfer that shaking to the player's body.  I don't want to hijack the thread, so I'll save that discussion for another thread.

Re: Adding a Transducer to a piano's Soundboard

Yes, the source of sound origin is something that I have been pondering.   The hammers and strings have a definite contribution separate from the soundboard - perhaps this is why Kawai supplements its transducers with speakers, while Yamaha does not. The sound of the action itself is created by the action, which works regardless of whether the stop bar is engaged or not, so at least we don't have to worry about that component.

I ordered a variety of emitters / transducers crom the company Parts Express to try on my soundboard.  They arrived yesterday, but I am away on a trip, so I haven't tried them yet.

More to follow, for sure!

- David

Re: Adding a Transducer to a piano's Soundboard

Yeah, soundboard activated by transducers are a interesting idea. I did some topics abou times ago.  It require speakers for high frequencies.

I imagined why not use tranducers not just to wood soundboards.  Why not transducers for steel or copper metal prates, to get the high ffrequencies ?

Re: Adding a Transducer to a piano's Soundboard

Well, you certainly can do transducers to metal, plastic, glass, etc.  I saw a YouTube video where a guy made a clean-sounding speaker with a one-foot square of aluminum sheet.

But if you have to supplement the soundboard, why not just use a speaker, since real pianos don't come with steel or copper plates to drive?

Similarly, I believe that Kawai uses a supplemental speaker or two.  Does anyone know oif Yamaha does, or is it only driving the soundboard?

- David

Re: Adding a Transducer to a piano's Soundboard

sjgcit wrote:

Cool.  With cream on top.


I'm not sure if Pianoteq sound models actually would work on this idea.  Wouldn't they need an actual transducer model in the sound system (instead of mics) to get the required output ?  Which incidentally might be an interesting idea for the next version.

I wonder how the harmonics and distortion generated by the vibrating wood would affect the tone. I believe the required output for a speaker like this should be simpler, but different for each model of transducer/material/size/shape/etc system.

Pianoteq Pro - Bechstein - Blüthner - Grotrian - K2 - Kremsegg 1 & 2 - Petrof - Steingraeber - Steinway B & D - YC5
Kawai CL35 & MP11

Re: Adding a Transducer to a piano's Soundboard

Practical scientific testing of transducers to DIY flat panel speakers for home costing say $30.

They tested a variety of materials including: steel, glass, aluminum, brass, polycarbonite, acrylic, pine wood, oak, resonant spruce, fibreglass, gypsym drywall, various grades of plywood, balsa wood, cardboard, plastic carboard, carbon fibre honeycone, carbon fibre/urathane, polyethylene, polyurethane, polystyrene.

The cardboard came out quite well from a price/performance perspective as size matters. Watch the video to see how the other materials fared and why:

https://www.youtube.com/watch?v=zdkyGDqU7xA

Re: Adding a Transducer to a piano's Soundboard

music_guy wrote:

The cardboard came out quite well from a price/performance perspective as size matters. Watch the video to see how the other materials fared and why:

https://www.youtube.com/watch?v=zdkyGDqU7xA

That's a great video. It's interesting that the end-grain balsa performed so well against traditional resonant spruce which is normally applied with the edge-grain. It's also cool that 3 of the top 4 materials are easy to buy from local hardware stores: end-grain balsa, extruded polystyrene and palette cardboard.

I'm still wondering why not a circular soundboard? Wish he had tested that. But the additional weights to balance the sound response was pretty cool!

Last edited by Groove On (06-05-2018 21:18)

Re: Adding a Transducer to a piano's Soundboard

Super video, indeed.  Have to give the guy quite a lot of credit for all the time and effort in not only the idea but the experiments and then the video production.  No wonder piano soundboards have the strakes/fins.

Well, more parts from parts express arrived, but I just got into town and don't have time to fool with things yet.

- David

Re: Adding a Transducer to a piano's Soundboard

dklein wrote:

Does anyone here have experience adding a transducer (or several) to a piano's soundboard?  It seems like this might be the purest way to have Pianoteq working in a "Player" capacity, similar to that of a Yamaha TransAcoustic or a Kawai hybrid.  I am contemplating such a project.

Here are some 'teaser videos':

https://www.youtube.com/watch?v=NTfl7o5xbyI   - an audio speaker made of spruce, as a type of alternative musical speaker

https://www.youtube.com/watch?v=TXmY9Oi2DXA   - David Pogue's review of the Yamaha U1 TransAcoustic

https://www.parts-express.com/resources...e-exciters  -  A parts company's page with videos on using transducers/exciters

http://www.denismusique.com/en/yamaha-u...lent-ta-pe  An interesting page showing how Yamaha doesn't stick stick transducers on the soundboard (as I was considering doing... hmm..?)

https://www.steingraeber.de/en/innovationen/transducer/

Pianoteq 8 Pro Studio with Classical Guitar and Organteq 2

Re: Adding a Transducer to a piano's Soundboard

!
this is the future and it's great to see it being given the serious attention it warrants! 

now, i wonder if that transducer module is available as a separate component...?

Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

My initial reaction is - just don't.

The piano soundboard is what we hear vibrating, it dominates the string sound.
Acoustically it is a set of filters - and in Pianoteq all of those filters are included in the model of whichever instrument we play.

I see no GOOD reason to put another set of filters in series with those, the job is already DONE.
Loudspeakers STRIVE to reproduce accurately, i.e. not add any filtering.

Re: Adding a Transducer to a piano's Soundboard

Part 2 of the the previous video. He delves further into different setups for the soundboards.

https://youtube.com/watch?v=CKIye4RZ-5k

Last edited by Groove On (28-06-2018 16:10)

Re: Adding a Transducer to a piano's Soundboard

Just curious, what are you folk watching these videos on ?
More important, how are you LISTENING to them ?
i.e. through WHAT "speakers" ?

Re: Adding a Transducer to a piano's Soundboard

aandrmusic wrote:

Just curious, what are you folk watching these videos on ?
More important, how are you LISTENING to them ?
i.e. through WHAT "speakers" ?

With sound exciters speakers will be everywhere. I am very interested to bought some of these and to go for some low range price amplifier like Alesis RA150 and as a speaker to use cheap violoncello but without strings. This man use guitar, in the end of the video there is some piano, jazz and classical music. Sounds very natural. Classical instruments sounds fantastic. Direct and with distance mics sounds like you are in the concert hall. Thats inspired me for my piano vst. Violoncello is little biger for more lows.
https://www.youtube.com/watch?v=GRJdIv_zvag

Last edited by slobajudge (30-06-2018 11:17)

Re: Adding a Transducer to a piano's Soundboard

Well, after letting them sit in a box for a while, I tried-out my collection of transducers/emitters that I had purchased from Parts Express, using a 20 watt amplifier from them, but substituting a really hefty 12v power supply.  I used my Mom's Steinway M as the soundboard, with me lying underneath and trying various transducers at different places on the soundboard.

Overall, I found that with the transducer placed just 'outside' the bridge, in the longer 'belly' section of the soundboard, I got the best response, with good sound quality.  Low volume was the problem - as soon as my Dad sat and played a few notes on the keyboard, I realized how woefully under-powered my transducer set-up is.  While some of the Parts Express transducers are rated at 40 watts, my gut impression is that it will take more of a 100 watt transducer and amplifier to drive the soundboard at a level to sound more like a 'live' piano.

Does anyone know a source of such transducer/emitters?

- David

P.S.  Gaston's Piano and Cello piece sounded really good, especially with respect to the cello - the large soundboard does it proud!

- David

Re: Adding a Transducer to a piano's Soundboard

Many commercial systems I’ve seen use multiple exciters matched to a high watt amp. For example, 6x25 watt exciters with a 200 watt amp (for some headroom).

The largest general purpose transducers I’ve seen are 40 watts at 32mm from Dayton Audio (through Parts Express). I’ve seen larger transducers but they all seem to have a special purpose like bone conducting.

I’m using the Dayton Audio 40 watt 32mm exciters with a matching 100 watt amp and bass shaker My setup can drive large / light DIY sound boards with fair volume, but I feel like heavier boards could use more power to get good and effortless volume.

And since Piano sound boards are designed to work under the tons of weight generated by the frame and metal strings - I  fear properly driving an acoustic piano sound board to effortless volume levels could take a lot more power.

Last edited by Groove On (14-07-2018 15:46)

Re: Adding a Transducer to a piano's Soundboard

I really don't understand the rationale behind using wooden soundboards on digital pianos, especially sampled ones.

Surely you want the recorded sound played back as faithfully as possible. The fact that the original piano uses a spruce soundboard is irrelevant. The sound of the piano is already "fully formed" by the time it's recorded, so the soundboard has served its purpose. It seems absurd that anyone would want to use anything other than a decent sound system to reproduce the recorded sound.

Re: Adding a Transducer to a piano's Soundboard

johnstaf wrote:

I really don't understand the rationale behind using wooden soundboards on digital pianos, especially sampled ones.

simple: sound radiation.  even the best of setups using monitors is a point system where the sources are localized.  however, a soundboard/transducer arrangement, in theory, accurately recreates the sort of sound radiation that an actual physical instrument produces.

Last edited by _DJ_ (15-07-2018 04:39)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

Groove On wrote:

And since Piano sound boards are designed to work under the tons of weight generated by the frame and metal strings - I  fear properly driving an acoustic piano sound board to effortless volume levels could take a lot more power.

this may be the case when dealing with the behemoth modern instrument, but it seems to me then that the earlier historic instrument models (esp the Walter & the Broadwood), given their physical analogs' much lighter construction, might be good candidates for a multi transducer/amp approach without having to have unreasonable amounts of power...?  & i wonder what the optimal amount of power and units might be? i'm sure it's some function of the area and material of the soundboard being used, as well as how it's supported...??

Last edited by _DJ_ (15-07-2018 05:08)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

dklein wrote:

While some of the Parts Express transducers are rated at 40 watts, my gut impression is that it will take more of a 100 watt transducer and amplifier to drive the soundboard at a level to sound more like a 'live' piano.

as GrooveOn suggests, 'possible to do multiple 40w transducers run in parallel?  and, if so, i wonder if there's a particular arrangement that would yield optimal distribution of energy to the soundboard?

Last edited by _DJ_ (15-07-2018 05:04)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

another thought: if one is using, say actual soundboard Sitka spruce, isn't that in effect adding a second component soundboard to the sound artifact being produced?—and so wouldn't that have to be taken into account in the modeled sound as generated by Pianoteq?  i wonder what, if any, adjustments were made to the Pianoteq setup used in that Steingraeber page about their "Transducer Grand Piano"?
it seems like a fascinating project, with i think bleeding-edge implications for the future of keyboard instruments and how we think of them, and so more details about "the physical modelling approach of piano sound ‘Guru’ Philippe Guillaume and his firm Modartt/pianoteq" as done for this particular project would sure be welcome! ...?

edit&ps: further, i wonder to what degree the modeled effect of the soundboard is discreet within Pianoteq's computation?  would it be possible to, admittedly simplistically as i'm way out of my depth here, have a switch to "shut it off" and thereby allow an actual soundboard to carry it's proper aspect & load from what's generated & sent to the transducers?

finally, it seems to me that mic placement in Pianoteq's virtual space is critical here as well.  i would think that the virtual mics, 1 channel per transducer, must correspond in coordinate space to the actual spatial position of the transducers on the physical soundboard... though i'm sure that there's as well considerable "sweetspot" play that one could do to shape and modify the sound. 

Last edited by _DJ_ (15-07-2018 05:19)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

johnstaf wrote:

Surely you want the recorded sound played back as faithfully as possible.

Yes, this is the rationale for the discussion.

Regular speakers are just transducers attached to a cone. A transducer attached to soundboard is the exact same technology. The only difference is the cone or soundboard.

So between the cone or soundboard speaker, which is more likely to faithfully reproduce the sound of a piano? I don’t know the full answer to all of this, but I think it is important to note that pianos, guitars, and violins are built as soundboard speakers with the bridge acting as the transducer.

Re: Pianoteq’s modeled soundboard
For practical purposes - a piano recording and the “fully formed” Pianoteq sound from the modeled soundboard are the same thing. They both need to be run through a cone or soundboard speaker, which still leaves us with the question - which is more likely to faithfully reproduce the sound: the cone or soundboard speaker?

Last edited by Groove On (15-07-2018 13:30)

Re: Adding a Transducer to a piano's Soundboard

Re: disabling the modeled soundboard in Pianoteq

This would cause a technical problem - if you only send the sound of individual modeled strings to an external physical soundboard you lose the sympathetic resonances of the other strings vibrating with the soundboard.

Last edited by Groove On (15-07-2018 13:26)

Re: Adding a Transducer to a piano's Soundboard

Johnstaf,

There are lots of absurd things that make life more fun! To each his own, and it certainly sounds like you really don't have interest in this pursuit with respect to the topic of adding a transducer to a piano's soundboard.

Here is a brief background of why I am interested: I have only started to learn to play a keyboard instrument as an adult about 3 years ago. I started with a hand-me-down Casio WK-3000, which I found quite limiting in dynamics because each note only had four separate possibilities: none (not pressed), piano, mezzo, and forte. This is when I discovered the Pianoteq software, back in version 5. Since that time, I gave away the Casio keyboard and bought an antique Steinway Model F upright. I had already become so enthralled by Philippe's synthesized pianos, as compared to the recorded sampled ones, that I installed a QRS MIDI strip under the keyboard of my Steinway for use with Pianoteq.

Good simulation [such as with flight simulators that now let companies like Boeing design planes from mere thought and fancy on  through flyable prototype, without experimental "mules" along the way as test planes] has been absolutely fascinating to me. So, when I realized that Philippe and the Moddart team have been doing the same thing for pianos, this sparked the idea that my goal would be to create a playing digital piano that was otherwise undiscernible from the acoustic piano on which my Steinway is based.

Therefore, sitting in front of me up against the wall, I have an upright piano that has MIDI output and possesses a soundboard. The soundboard works great when I play the real acoustic piano, but when I move the stop bar so that the hammers no longer strike the strings, and I only have MIDI output, I route the sound through speakers. I am using some decent monitor speakers made by Emotiva, but because of my space and arrangement within the room, the speakers are to the right and to the left of the piano and not behind or on top of it. While I have been able to tweak things so that I get a pretty good stereo image, I thought that the ultimate would be to have the soundboard itself be the radiator, similar to Yamaha's trans-acoustic series (as well as now, as I learned, the Kawai's and the Steingraeber's). If I'm able to get a realistic sound out of the piano's keyboard, then it should make no difference whether I play just the acoustic piano, a combination of the acoustic piano plus the synthetic piano, or just the synthetic piano. That would fit my 'absurd' goal of being able to have someone sit down at the Steinway's keyboard and start playing, ideally not being able to tell whether they are listening to hammers striking strings and producing resonance in a purely acoustic fashion, or keys talking to a MIDI interface and driving a soundboard in a digitally synthesized fashion.

By the way, I have contacted the company that makes transducers that Steingraeber uses, driveable by 80-100 watts, so I will buy these +/- some 40 watt ones from Dayton Audio/Parts Express.

- David

- David

Re: Adding a Transducer to a piano's Soundboard

_DJ_ wrote:
johnstaf wrote:

I really don't understand the rationale behind using wooden soundboards on digital pianos, especially sampled ones.

simple: sound radiation.  even the best of setups using monitors is a point system where the sources are localized.  however, a soundboard/transducer arrangement, in theory, accurately recreates the sort of sound radiation that an actual physical instrument produces.

+1. Exactly the reason why Yamaha use this technology in their new acoustic hybrid pianos

Last edited by slobajudge (15-07-2018 18:34)

Re: Adding a Transducer to a piano's Soundboard

Yes. I put transducers in my 1884 Mathushek square piano. I removed the original action and installed a Native Instruments K88. I kept the sound board, and all the strings. Using Pianoteq software, the sound is fantastic. The original strings vibrate in sympathy with the generated sound.

Re: Adding a Transducer to a piano's Soundboard

I used two Dayton Audio transducers powered with an amp intended for use in an automobile. As noted above, the host is an antique square piano.
photos here:
https://www.flickr.com/gp/159658424@N08/H05152

Re: Adding a Transducer to a piano's Soundboard

Very cool!  Which transducers did you use, and how many in total?  I see four items.

After initially buying the Lepai 20 watt amp, and using a much better power supply, I couldn't get any of the variety of Dayton 20 watt or 40 watt transducers to give enough volume as held to my Mom's piano soundboard.  I gave the group to my nephew to play with, and now reordered only the 40 watt 4 ohm versions, which I will try running off of a more powerful amp.

- David

Re: Adding a Transducer to a piano's Soundboard

Hey dklein,
I used the DAEX25VT-4 Vented 25mm Exciter 20W 4 Ohm. This is the unit shown inside the piano in one of the pictures. It is affixed to the underside of the sound board. I found the sweet spots by sliding the unit around while paying a variety of keys. After deciding on locations I peeled off the kraft paper and pressed the unit against the wood. The 3M adhesive has worked well - I was a bit worried about them falling off, but so far no issues.
I used two units, and am feeding them with a stereo amp. I don't recall the brand, (Lepai?) but it is an aftermarket amp intended for use in a car. I mounted it under the piano, with the knobs placed for access while seated - much the same as the TransAcoustic pianos. The amp also has a separate feed for a sub-woofer, which I had intended to connect to a third exciter - a thumper. But I did not need it.
The sound quality is quite good - it compares in an A to B test with my reference monitors. Not the same sound, but high fidelity. The best part is that the sound comes from the right location - and that I get the 'afterglow'. When you strike a chord, and then release the sustain pedal, the original strings ring softly much in the same way as an acoustic piano.
The one issue is the age of the sound board. As with nearly all sound boards of this age, it has split in a number of places, where the glue holding the strips of wood has dried out. (likely animal glue) I must maintain a high humidity in the room to avoid buzzing from the cracks.
One last note - the picture showing the amp and exciters on the top of the sound board is actually the stuff I didn't use. The units noted above sounded about the same, but I did not want to see any of the gear, so the peel and stick feature was the decider.

Re: Adding a Transducer to a piano's Soundboard

So1968, how about oiling your soundboard as you might do a piece of dry furniture?  I don't know whether it 'wood' have adverse effects or not (other than loosening the glue on your transducers).

I have transducers on order from Parts Express and from Hidden Audio.  I'll see what happens.

Cool project you've got there!

- David

- David

Re: Adding a Transducer to a piano's Soundboard

Many thanks David, So1968, et al for your very helpful & inspiring infos presented here!!  I'm very excited by these developments and think that i'll dive into the pool as well after returning from the summer holiday! 

dklein wrote:

I have contacted the company that makes transducers that Steingraeber uses, driveable by 80-100 watts

David, can you please give some more info on this?  (ie which company is it and what's their contact info? are they indeed amenable to selling these retail to end-users?  how much are they asking per unit? etc)

i've been cursorily looking around for 80w transducers but the only thing i seem to be able to find are ultrasonic equipment or "bass kickers"... i assume the latter have some kind of built-in cutoff filter and so wouldn't be suitable for our purposes, or?

lacking 80w transducers (though apparently, according to the video, they're used as well in those JMC Soundboard "speakers" listed in the OP... hmm... ), my current thinking is to run four DAEX32EP-4 Thruster 32mm Exciters (40W 4 Ohm) off of an ART SLA-4 (400w, 4x140 Watts/Ch @ 4 Ohms), and have some pianoforte maker (Secker perhaps?) build me a framed soundboard (with detachable legs) to fit them to ('thinking attached along where the bridges would be?)...

i'd also like to keep my Dynaudio powered sub in the chain, but as it only has two channels the question becomes which channels (the front two or back two) to route through it?

i'm curious though: @So1968, when you say "Not the same sound, but high fidelity" can you elaborate a little on that please?  as i suggested above, is it perhaps something like "a second component soundboard [being added] to the sound artifact being produced"?

as well, i'm still very curious as to what, if anything?, Modartt did to the Pianoteq model when used in conjunction with the Steingraeber "Transducer Piano"...

in any event, further observations, critiques, insights, etc would be most welcome here!

cheers,
dj

Last edited by _DJ_ (20-07-2018 10:00)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

Not my subject, but fascinating. I was struck by the name of a possible builder of a framed soundboard. Would this be Johannes (John) Secker of Lythe N Yorks? A friend who goes way back. I have spent many hours over the years playing his instruments which are of superb quality. Anyone who would like to enter this field by acquiring a soundboard for harpsichord, fortepiano or 19thC pianos should bear him in mind. (And before he finally retires)

Re: Adding a Transducer to a piano's Soundboard

sandalholme wrote:

Not my subject, but fascinating. I was struck by the name of a possible builder of a framed soundboard. Would this be Johannes (John) Secker of Lythe N Yorks? A friend who goes way back. I have spent many hours over the years playing his instruments which are of superb quality. Anyone who would like to enter this field by acquiring a soundboard for harpsichord, fortepiano or 19thC pianos should bear him in mind. (And before he finally retires)

the very same!  i'll definitely look him up when i return from holiday, but do you think he might be amenable and disposed to such a project (ie building just the soundboard component of 1814 N. Streicher, framed & braced, and with detachable legs, but no case, action, lid, strings, bridges, etc)?

Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

Here's some of the Steingraeber pages:

     https://www.steingraeber.de/en/innovationen/transducer/

     https://www.steingraeber.de/wp-content/...t_2018.pdf

And here is the website for the Hidden Audio company, which I found from reading the label on the Steingraeber photo:

     http://www.hiddenaudiosystems.com/index.html

     sales@hiddenaudiosystems.com

They have both 4 ohm and 8 ohm drivers, HAS 401 and HAS 801, 100-watt-amp appropriate (with built-in overload cutoffs), for about $110 each.  I have ordered two of the 4 ohm units, which I will likely pair with two of the smaller 4 ohm units from parts express, figuring that I might need separate drivers to help bass vs treble.  I have not tried them yet.

- David

- David

Re: Adding a Transducer to a piano's Soundboard

dklein wrote:

Here's some of the Steingraeber pages:

     https://www.steingraeber.de/en/innovationen/transducer/

     https://www.steingraeber.de/wp-content/...t_2018.pdf

And here is the website for the Hidden Audio company, which I found from reading the label on the Steingraeber photo:

     http://www.hiddenaudiosystems.com/index.html

     sales@hiddenaudiosystems.com

They have both 4 ohm and 8 ohm drivers, HAS 401 and HAS 801, 100-watt-amp appropriate (with built-in overload cutoffs), for about $110 each.  I have ordered two of the 4 ohm units, which I will likely pair with two of the smaller 4 ohm units from parts express, figuring that I might need separate drivers to help bass vs treble.  I have not tried them yet.

- David

Thanks, David!

Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

_DJ_ wrote:
sandalholme wrote:

Not my subject, but fascinating. I was struck by the name of a possible builder of a framed soundboard. Would this be Johannes (John) Secker of Lythe N Yorks? A friend who goes way back. I have spent many hours over the years playing his instruments which are of superb quality. Anyone who would like to enter this field by acquiring a soundboard for harpsichord, fortepiano or 19thC pianos should bear him in mind. (And before he finally retires)

the very same!  i'll definitely look him up when i return from holiday, but do you think he might be amenable and disposed to such a project (ie building just the soundboard component of 1814 N. Streicher, framed & braced, and with detachable legs, but no case, action, lid, strings, bridges, etc)?

He may. I know he has cut down on work, but it's much less work than making a complete instrument. He's reasonably accepting of digital instruments and may be interested in your project. I'm not averse to people knowing my name, and would be amused to know how long it takes John to identify me when you contact him and say your mention of his name on a piano forum provoked a reply from someone he knows whose forum name is sandalholme.

Re: Adding a Transducer to a piano's Soundboard

So1968, how about oiling your soundboard as you might do a piece of dry furniture?

My concern with oiling it is filling up the pores of the wood with oil may dampen the sound? What I can find online suggests inserting slivers of wood into the crack, and re-gluing. I have not yet developed the courage to try this.

I am very interested in your research with the Steingraeber lead.

Re: Adding a Transducer to a piano's Soundboard

My understanding, having "played in" harpsichords and therefore picked up a few points from makers and having my own harpsichord's soundboard repaired is the same: insertion of slivers of wood. Presumably matching the original material as far as possible. Not sure abut pianos, but harpsichord soundboards are not constant in depth, so the depth of each sliver may vary.

Re: Adding a Transducer to a piano's Soundboard

So1968 wrote:

What I can find online suggests inserting slivers of wood into the crack, and re-gluing. I have not yet developed the courage to try this.

if you do venture upon using shims (which i believe is, as sandalholme suggests, really your only recourse) then make sure to watch your epoxy use.  i'd heartily recommend trying some test glue-ups first to get your mixture and technique right and to make sure you're able to use it effectively before it starts to "kick"... you'll probably also have a little bit of delicate planing & sanding (especially along the crown line) to do...

bon courage!
dj

Last edited by _DJ_ (20-07-2018 17:43)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

_DJ_ wrote:

Many thanks David, So1968, et al for your very helpful & inspiring infos presented here!!  I'm very excited by these developments and think that i'll dive into the pool as well after returning from the summer holiday! 

i'm curious though: @So1968, when you say "Not the same sound, but high fidelity" can you elaborate a little on that please?  as i suggested above, is it perhaps something like "a second component soundboard [being added] to the sound artifact being produced"?
dj

_DJ_
The sound produced by the monitors is supposedly flat. The woofers in my monitors are rather small (6"), and are limited at the low end. The transducers (Dayton calls them 'exciters') do a better job of producing the low end of the piano range - that copper-wound twang that you hear when a mallet strikes a long single string at the bass end of a grand piano. The mid-range and upper notes and harmonics are also different, but it is qualitative, and hard to describe. You can hear that they are different-perhaps the harmonics are rendered differently. I also get sympathetic tones from the strings (they are in tune).

What is quite noticeable is that when all the sound comes from the sound board, the perceived location changes in direct proportion to the location of the key(s) being played. The output is stereo, and there are two exciters, so I'm guessing that the software pans the signal left to right accordingly.

Re: Adding a Transducer to a piano's Soundboard

So1968 wrote:

The sound produced by the monitors is supposedly flat. The woofers in my monitors are rather small (6"), and are limited at the low end. The transducers (Dayton calls them 'exciters') do a better job of producing the low end of the piano range - that copper-wound twang that you hear when a mallet strikes a long single string at the bass end of a grand piano. The mid-range and upper notes and harmonics are also different, but it is qualitative, and hard to describe. You can hear that they are different-perhaps the harmonics are rendered differently. I also get sympathetic tones from the strings (they are in tune).

What is quite noticeable is that when all the sound comes from the sound board, the perceived location changes in direct proportion to the location of the key(s) being played. The output is stereo, and there are two exciters, so I'm guessing that the software pans the signal left to right accordingly.

thanks, So1968—this all sounds encouraging!

i play with many different diapasons & temperaments though, so _not_ having sympathetic strings in addition to what the model is already producing will probably be a plus in my proposed setup...

another question: what sort of a mic setup are you using in Pianoteq?  have you experimented at all with placing Pianoteq's perfect omnis in the same coordinate position as your transducers occupy in physical space with respect to your instrument's actual soundboard?

cheers,
dj

Last edited by _DJ_ (22-07-2018 04:02)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

dklein wrote:

After initially buying the Lepai 20 watt amp, and using a much better power supply, I couldn't get any of the variety of Dayton 20 watt or 40 watt transducers to give enough volume as held to my Mom's piano soundboard.  I gave the group to my nephew to play with, and now reordered only the 40 watt 4 ohm versions, which I will try running off of a more powerful amp.

David, what amp are you going to use to run your new HAS 401s?  'am going to be very eager to hear about your results!

i also found it interesting that the suggested positioning for four exciters given here seems awfully similar to where the bridge on a soundboard would go and i'm guessing informed by the same reasons...

Once the mounting surface material, shape, and size are known, the exciters can be placed. Exciter placement is critical to achieving uniform excitation of the surface while maintaining wide dispersion. For the best results, exciters should be placed near the center of the mounting surface, but should be offset from each edge of the surface so that the distance from the exciter to the edge is not an even multiple of the distance from the exciter to another edge of the panel, in order to avoid the buildup of standing waves.

For mounting exciters to a flat rectangular panel (a common application), the width of the panel should be less than 4/5 of the height, or vice versa, and good results will be given with the exciter mounted a distance of 2/5 of the panel width from one side of the panel, and 3/5 from the other side of the panel, with the same relationship used for exciter placement with respect to the panel height. This relationship will provide a satisfactory offset to reduce the buildup of standing waves on the panel.

https://www.parts-express.com/Themes/Default/Images/Company_Pages/exciters/installation_1.jpg

If multiple exciters are needed for a panel or surface, it is not recommended to space the exciters evenly across the surface. This will result in very narrow sound dispersion at upper midrange and treble frequencies. Instead, place the exciters together in a group, with exciters at unequal distances from the panel edges and from one another.[emphasis mine]

i'm also curious what the effect might be of having a pair of transducers on either side of the soundboard (instead of all four on the same side), similar in idea to Stein's "counterbridge" setup on some fortepianos...?

[and speaking of Stein, here's some Haydn on one of Secker's beautiful Steins ==> https://www.youtube.com/watch?v=qp3E-tpZsKk  oh, what i wouldn't give for a Stein in Pianoteq!  not to mention a N. Streicher instrument, or a Boisselot, or ...!! ]

cheers,
dj

Last edited by _DJ_ (22-07-2018 04:14)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

thanks, So1968—this all sounds encouraging!

i play with many different diapasons & temperaments though, so _not_ having sympathetic strings in addition to what the model is already producing will probably be a plus in my proposed setup...

another question: what sort of a mic setup are you using in Pianoteq?  have you experimented at all with placing Pianoteq's perfect omnis in the same coordinate position as your transducers occupy in physical space with respect to your instrument's actual soundboard?

cheers,
dj

_DJ_
Now there's an idea - no I had not thought to do that , but I will now experiment with mic placement.

Going back to my sympathetic strings, I understand what you are getting at. For the most part, having the real strings add an afterglow to the sound is an eccentric indulgence. Something to do with the ghost of the music played a hundred years ago.

Re: Adding a Transducer to a piano's Soundboard

sandalholme wrote:

He may. I know he has cut down on work, but it's much less work than making a complete instrument. He's reasonably accepting of digital instruments and may be interested in your project. I'm not averse to people knowing my name, and would be amused to know how long it takes John to identify me when you contact him and say your mention of his name on a piano forum provoked a reply from someone he knows whose forum name is sandalholme.

@sandalholme: I've been in touch with Mr. Secker and, while your handle hasn't wrung any bells for him so far, I'm pleased to report that he's indeed interested/intrigued in/by my project.  'will be making the trek up north to visit him at his shop in the next couple of weeks or so to hash out details etc.

in other news, i've written to Hidden Audio about their transducers but haven't heard back yet... 'hope though to have word soon so as to likewise place an order with them for four HAS401s! 

cheers all,
dj

Last edited by _DJ_ (26-07-2018 04:26)
Matthieu 7:6

Re: Adding a Transducer to a piano's Soundboard

dklein wrote:

Johnstaf,

There are lots of absurd things that make life more fun! To each his own, and it certainly sounds like you really don't have interest in this pursuit with respect to the topic of adding a transducer to a piano's soundboard.

On the contrary David. I think it's fascinating. I was referring to the idea that because a soundboard is spruce, that somehow passing a signal recorded through a microphone through a spruce board will somehow make it sound more like a piano. Surely it's irrelevant how the sound was originally created. This kind of marketing logic always leaves me somewhat bewildered.

Of course it's a good idea to try and have a larger radiating surface, but when you get to the point when Yamaha are using spruce pulp in their speakers it just strikes me as silly. It's a bit like saying we should use leather speakers for voices, because vocal cords are made of meat. ;-)

I'd like to see a transducer used that models the string/soundboard interface, in order to make the whole system behave like a real piano. That's something Pianoteq could probably develop. Of course there's a lot of fun, and useful research, to be had by experimenting, but the marketing used for digital pianos can get a little bit ridiculous at times.

It would be interesting to see panel speakers like electrostatics used in pianos.

Last edited by johnstaf (04-08-2018 21:26)