Moog Theremini!

I did. Need more beef.

Regarding latency -- the latency is the sum of the theremin's latency, digital processing latency, and the delay from the monitor to the thereminist.  An overall latency more than 8-10 ms is enough to cause problems and at 12-15ms a theremin is utterly and completely unplayable.  -  kkissinger

This is probably the wrong thread for this, but all this talk about latency brings up a phenomenon that I have noticed.  Normally when I practice with my Etherwave I wear headphones and frequently feel that I am really in good control of the instrument.  When I play without headphones I find it more difficult to play, at least for a while.  Now sound travels at roughly 1000 feet per second, or 1 foot per ms.  The distance from my ears to the speaker is about 5 feet, for a 5ms delay compared to using the headphones.  (The effective distance is probably somewhat greater with all the reflections around the room.)  Two other possibilities come to mind - perhaps the linearity is different when wearing the headphones, or maybe removing the headphones lets me hear just how bad I really am. But after playing for maybe 5 minutes I seem to settle down and get in better control.  Has anyone else noticed this phenomenon and if so do you have ideas why it happens?  This would be another good argument for pitch preview if that amount of latency causes problems.

The problem with the Moog THEREMINI is more serious that simple latency.

“Latency” suggests that the instrument is accurately following your pitch gestures but delivering them, as audio, with a slight delay. 

The problem with the THEREMINI is far more serious than that. The instrument is not able to sample at a sufficiently fast rate to capture rapid hand gestures, such as the kind you would use in fast vibrato. So what it does is “smooth” the sound to eliminate any sounds produced by gestures that are too quick to fall within the limitations of its sampling rate. 

Don’t forget, unlike the instruments of Leon Theremin, the THEREMINI does not operate on the heterodyne principle. It is a not particularly powerful digital synthesizer.

Gordon Charlton explained it beautifully several months ago…..I’m not quite sure where…..

"... perhaps the linearity is different when wearing the headphones..."  - senior_falcon

Wearing headphones will likely improve the grounding disposition of your body, and grounding is the return path by which you control your Theremin capacitively.

Moog will soon release a new fw for the theremini that supposedly improves the linearity and adds a new 'theremin mode' where the knobs are used to directly trim pitch and volume.   

oops- correction.  There will be a new firmware available soon.

"Moog will soon release a new fw for the theremini that supposedly improves the linearity and adds a new 'theremin mode' where the knobs are used to directly trim pitch and volume."  - Chobbs

Any word on fixing the super low gestural bandwidth?

Dewster, is “low gestural bandwidth” what is responsible for the “smoothing” effect I described above?

“Latency” suggests that the instrument is accurately following your pitch gestures but delivering them, as audio, with a slight delay.  The problem with the THEREMINI is far more serious than that. The instrument is not able to sample at a sufficiently fast rate to capture rapid hand gestures, such as the kind you would use in fast vibrato. So what it does is “smooth” the sound to eliminate any sounds produced by gestures that are too quick to fall within the limitations of its sampling rate. " - Coalport

The "smoothing" effect on the theremini is almost exactly the same as deliberate "portamento" on electronic keyboards.. With portamento, the pitch will glide from the "source" key to the "target" key in a (user) adjustable time.. With a keyboard, this is no problem - you play the target key and you know that the pitch will get to it, and you can set the time to whatever you want.

The theremini has permanent portamento of  ~100ms (1/10th of a second) - this would be intolerable even for a keyboard synthesiser where one knows that the pitch will eventual reach the key being played IF that key is held for the required 1/10th of a second.. But with a theremin where one doesn't have a keyboard and must rely on audio to direct ones movement, it is utterly useless and makes the "instrument" utterly unplayable as a theremin.

As to the mechanism - Whether this is due to sampling rate or error smoothing or whatever, and as to whether it should be called "latency" or "low gestural bandwidth" (a good description) it all comes down to the same thing - the pitch takes about 100ms before it settles to produce the correct pitch for any player movement, this means that any pitch modulation more rapid than 10Hz will be severely attenuated, and even slower movements will be severely affected (33% latency or time 'distortion' on a change taking 1/3 second).

Putting the theremini's "performance" in the context of other electronic instruments, it is truly beyond belief that anyone would release such a pile of crap on the market and get away with it, and its only because people are not familiar with theremin operation and dont know what to expect, that Moog haven't been lambasted and laughed out of town.. They have taken the most responsive electronic musical instrument ever invented and turned in into the least responsive instrument on the market.. It actually wouldn't surprise me if the theremini was the least responsive electronic musical toy ever created!

Fred.

"Any word on fixing the super low gestural bandwidth?"

I cant disclose the details now.  I recon that it will be released soon and Moog usually releases a changelog with new fw.  Sorry ;(