Upright piano speaker simulator addon idea

dore_m Wondering what you thought about the addition of different materials.

I tried a few materials, the main issue is that the more the material weights, the less the drivers are able to move them enough, so everything is very, very quiet (often less than a whisper). The more mass you add, the worse this would be, and that is confirmed with my experiments. Everything else, is just a mechanical way of doing frequency equalization, which in my opinion could be more easily done in software, as long as the final "speaker" is not horrible with huge resonances or response gaps.

So my todo list on this is to try the larger piece of insulation which would fit my DIY hybrid (I've already cut it, have to find the time to do all the rest) and insulation panels with different compression strengths. The supplier I contacted told me they were going to send me and estimate for such panels, but never did (perhaps after the holidays?) -- I don't see strong reasons to experiment otherwise, and have to carefully budget my spare time.

Pianissimo listening to this comparison I prefer the Klipsch compared to the panels.

You may like the "tone" (i.e. frequency response) of the Klipsch better, but I'm 200% (sic) convinced that if you listen to these in person you would like them better for the soundstage. As I said above, you can adjust the frequency equalization by other means, but you cannot create the soundstage that even one of these speakers provide, unless you use a huge number of speakers, as they do in movie theaters. Let me quote my previous post:

RIP The soundstage is incredible, absolutely astonishing (with the right recording). A random (but good) CD of a Teresa Milanollo compositions made a violin player literally materialize in front of me. Other recordings with more reverb, probably mic'ed from a distance, made me think I was in a cathedral. Never experienced anything like that with speakers, definitely feels like "being there". My wife, who is usually totally numb to my audio experimentation, looked at me in awe when I forced her to go in that room and have a listen. Pianoteq blues demo also made the piano materialize just behind the panels, I felt I could touch it.

The previous quote is not bragging, it is really "an experience". Given how cheap it is to experiment with these, I suggest to anybody who has an even slight curiosity and a possible location to place the built speaker(s) to build one or two.

Ok, so I tried these in the context of a hybrid piano with a grand action and the short upright form factor. The one most of you have probably already seen here: https://pianoclack.com/forum/d/170-build-your-own-hybrid-piano-step-two-the-cabinet

Because of the geometry, the size of the "soundboard" was forced to be a spinet-like configuration.

The results have been disappointing in this application. I did not like the class-D amplifiers I tried, but I could have probably lived with them (or use a conventional class AB). What was different this time is that I was forced to use smaller panels because I needed to have them fit the available space in the instrument. There were three panels, two could be at most 20"'x16" (which on paper looked not much smaller than 24"x24" and better per the manufacturer recommendation to use rectangles rather than square); the other could be 4'x1' which I thought could give it more bass which was (somewhat) lacking on the 2'x2'.

Long story short: if you are constrained by dimensions similar to these, forget it. It works, it's decent, but any non-crap Bluetooth speaker will outperform this setup. The most disappointing aspects are:

• even more distortion and clipping problems
• not enough bass, despite the 4' dimension which on paper should allow lower frequencies than the 2' (not half because you have the diagonal, but still lower)
• because of smaller total area, obviously lower volume levels (insufficient for a digital piano, and I never went more than 10 or 11 am on the volume settings on any digital piano I owned, just so you understand you are not talking with one who wants the digital have the same volume of a concert grand)
• that lower volume level (compared to the 2' panels) was so even when utilizing more powerful Dayton Audio DAEX32QMB-4 exciters which are 40W rather than 20W
• most annoyingly a metal-like ringing/reverberation in any sound including voice (like when speaking in those toy-microphones which have only a vibrating piece of metal inside without any actual mic or electronics). This was both with the exciters I used earlier, and with the new 40W pair I tried -- and did not go away by rounding the corners of the panel as suggested online (even though it became somewhat better). I suspect that was caused by standing waves across the short dimensions of the panels, and it might be possible to damp them, but I did not investigate this (see comment below)
• the location I was forced to utilize for the panels (again, similar to the soundboard location for a spinet) did not create the soundstage I was hoping. Not by a long margin.

As such, I'm ditching this option for this application. Perhaps with some finite elements analysis one could make it much better than I was able to, but my time is limited and I have to set priorities -- and this isn't. I'll use regular speakers.

I still believe that these panels/exciters are a nice option to consider, as speakers for low-volume applications (and in such a case random experimentation yields at least decent results), but I'd say if you don't have room for at least a 2'x2' panel per channel (i.e. at least 4'x2', and probably twice that much), and possibly not too different from ear level, forget it. I will experiment more for the latter application to augment/complement my floorstanding Polk Audio speaker -- but not for the piano and not soon.

I always wanted to try the big electrostatic speakers (e.g. Martin Logan or Magnepan) with a piano VI.

Some of these just run a huge sheet of mylar & no have woofer (or crossover). They can sound smooth and full at mid- to high-frequencies, to my ears.

Even the big electrostatics didn't have great lower-bass response but maybe not so necessary for piano. Subwoofers could be added; I don't know if the change in form at very low frequencies matters so much; low frequencies are a strange beast.

I wish I had done this https://pianoclack.com/forum/d/361-simple-strokes-for-simple-folks-sound-improvement-on-the-cheap/11 for my now-scrapped soundboard experiment. I still have most of the parts (well, not all of the exciters and not the class D amplifier, since I returned them), so I can still redo the experiment, one day when I have enough time and stamina…. Not today for sure, life is busy and energy has been sucked by other things (hard disk that was having problems finally dead, potential loss of lots of pictures of my young kids; unrelated computer screen reaching end of life; and many other things which I won't bother you with)

@dore_m and @Pete14 you may be interested in what this guy is doing, which to my knowledge is the first DIY'er finally reaching acceptable/decent results with soundboards. Not sure the thing is transferable to a generic VST (he's using PTQ), but still worth a look even if one doesn't like PTQ.

https://forum.modartt.com/viewtopic.php?id=5674