4 ms·

I was thinking more like the burgeoning mechanical keyboard business for computers. If the mechanical structure was there your could provide arbitrarily low lat

I was thinking more like the burgeoning mechanical keyboard business for computers. If the mechanical structure was there your could provide arbitrarily low latency (some of the high end 'gamer' keyboards are sub-millesecond). Given the physical system you're modelling (Harpsichord, Piano, Etc.) all of the computation vis-a-vis the velocity can be computed while the key is moving and delivered when the key is "down", after touch on a per-board basis is easy, per key basis doable with more sensors. After touch doesn't have quite the latency requirements either. With these 25 cent M0+ 45MHz processors you could put one on every single key and 88 keys would incur like $88 cost for electronics.

jacquesm 3y ago
I wouldn't be able to build a substitute for a half decent brand-new manufactured keyboard for $88 if I got the parts for free. I've build some interesting musical keyboards but mostly because they had geometries that were non-standard and I'm still toying with the idea of making a complete action from scratch. But that's 'madman' territory, just as a challenge, not for cost savings.
- ChuckMcM 3y ago
  Sorry I wasn't clear, I was think just the electronics at $1 per key. The action for the keyboard would cost more than that. In my alternate life I find a broken/disused KX-88 and rebuild its keyboard :-)
  - jacquesm 3y ago
    Shall I keep an eye out? I repair DX-7's to keep them alive (usually three broken ones yield about two good ones and some spare bits), I can look for KX-88's while looking for DX-7s if you want.
    - ChuckMcM 3y ago
      I periodically search Craigslist for them and I've asked the local gear reseller (Starving Musician) to be on the eye out for a "dead" one. I seriously doubt having one shipped would be cost effective :-). There is a $50 one on Ebay in Illinois for local pickup.
      - jacquesm 3y ago
        That will be hard to beat :) Go grab it then! For that kind of money you really can't go wrong.
munificent 3y ago
For what it's worth, I've been into hardware and software synthesizers for a while and in the many many discussions I've seen around MIDI controllers and keyboards, I can't recall latency ever coming up. As far as I can tell, basically all MIDI hardware is fast enough that musicians don't seem to notice or complain.
- gsliepen 3y ago
  If the MIDI controller is connected via USB and is polled at 1 ms, you have only about that amount of lag. This is not something most people can even notice. Also, consider that even playing an acoustic piano has quite some lag: your brain has to send a signal to the muscles in your hand, which have to contract, which presses the key which takes some time to travel down, the hammers needs some time to travel to the strings, then the sound takes some time to travel to your ear. All this adds up to many milliseconds of delay. A musician already compensates for all that by starting the hand motions earlier to compensate for that lag. As long as it is not too large and if it is consistent, a few milliseconds extra does not matter.
  - bigiain 3y ago
    So 3 milliseconds is about how long it takes sound to travel 1 meter. So it's like the difference between how far a pianist sits from the strings in an upright vs a grand piano. Or the guitar player taking a couple of steps away from their amp. Or the difference between a drummer hitting the snare or their crash cymbal. One of my local theatres says the stage is 19m wide, so an orchestra playing there is probably 50 ms apart for onmstruments playing on opposite sides of the stage. Hell, you've got most of a millisecond of "lag" between your left and right ears for sounds coming from the side.
    - jacquesm 3y ago
      Submillisecond differences for audio > 1 KHz tend to show up as phase differences (after all: 1 ms period == 1 KHz) which allow you to figure out where something is located. The difference between your right and your left ear is indeed on that order and so phase change really starts at roughly that frequency and below that it all just blends together. That's why bass speakers aren't directional and you can have a single big woofer in the middle and it won't make much of a difference in what the sound is like in the stereo image. But if you collapse your high or mid then suddenly all sense of position is gone. So anything below 1 ms is negligible, as long as it isn't so long that it starts to confuse you. Not rare in church organs, where the lag can be so long that you wonder if you've depressed the key at all, you get used to it after a while but it is a very weird experience. It's interesting that you can spot an out-of-phase wired woofer fairly easily by just moving around the room, if the sound of the bases cancels out in the middle that usually a good sign that either woofer has its polarity reversed from what it should be. The sound will be 'hollow' (I have no better term for it, that's what it sounds like to me).

jacquesm 3y ago

I wouldn't be able to build a substitute for a half decent brand-new manufactured keyboard for $88 if I got the parts for free. I've build some interesting musical keyboards but mostly because they had geometries that were non-standard and I'm still toying with the idea of making a complete action from scratch. But that's 'madman' territory, just as a challenge, not for cost savings.

ChuckMcM 3y ago
Sorry I wasn't clear, I was think just the electronics at $1 per key. The action for the keyboard would cost more than that. In my alternate life I find a broken/disused KX-88 and rebuild its keyboard :-)
- jacquesm 3y ago
  Shall I keep an eye out? I repair DX-7's to keep them alive (usually three broken ones yield about two good ones and some spare bits), I can look for KX-88's while looking for DX-7s if you want.
  - ChuckMcM 3y ago
    I periodically search Craigslist for them and I've asked the local gear reseller (Starving Musician) to be on the eye out for a "dead" one. I seriously doubt having one shipped would be cost effective :-). There is a $50 one on Ebay in Illinois for local pickup.
    - jacquesm 3y ago
      That will be hard to beat :) Go grab it then! For that kind of money you really can't go wrong.

munificent 3y ago

For what it's worth, I've been into hardware and software synthesizers for a while and in the many many discussions I've seen around MIDI controllers and keyboards, I can't recall latency ever coming up. As far as I can tell, basically all MIDI hardware is fast enough that musicians don't seem to notice or complain.

gsliepen 3y ago
If the MIDI controller is connected via USB and is polled at 1 ms, you have only about that amount of lag. This is not something most people can even notice. Also, consider that even playing an acoustic piano has quite some lag: your brain has to send a signal to the muscles in your hand, which have to contract, which presses the key which takes some time to travel down, the hammers needs some time to travel to the strings, then the sound takes some time to travel to your ear. All this adds up to many milliseconds of delay. A musician already compensates for all that by starting the hand motions earlier to compensate for that lag. As long as it is not too large and if it is consistent, a few milliseconds extra does not matter.
- bigiain 3y ago
  So 3 milliseconds is about how long it takes sound to travel 1 meter. So it's like the difference between how far a pianist sits from the strings in an upright vs a grand piano. Or the guitar player taking a couple of steps away from their amp. Or the difference between a drummer hitting the snare or their crash cymbal. One of my local theatres says the stage is 19m wide, so an orchestra playing there is probably 50 ms apart for onmstruments playing on opposite sides of the stage. Hell, you've got most of a millisecond of "lag" between your left and right ears for sounds coming from the side.
  - jacquesm 3y ago
    Submillisecond differences for audio > 1 KHz tend to show up as phase differences (after all: 1 ms period == 1 KHz) which allow you to figure out where something is located. The difference between your right and your left ear is indeed on that order and so phase change really starts at roughly that frequency and below that it all just blends together. That's why bass speakers aren't directional and you can have a single big woofer in the middle and it won't make much of a difference in what the sound is like in the stereo image. But if you collapse your high or mid then suddenly all sense of position is gone. So anything below 1 ms is negligible, as long as it isn't so long that it starts to confuse you. Not rare in church organs, where the lag can be so long that you wonder if you've depressed the key at all, you get used to it after a while but it is a very weird experience. It's interesting that you can spot an out-of-phase wired woofer fairly easily by just moving around the room, if the sound of the bases cancels out in the middle that usually a good sign that either woofer has its polarity reversed from what it should be. The sound will be 'hollow' (I have no better term for it, that's what it sounds like to me).