NTL2009
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But don't we have two inputs here? The clarinet (carrier) and the singing tone (modulator)?Baluncore said:I disagree, it is a difference frequency if it comes from two inputs.
Or maybe I'm misreading your comment - are you agreeing that it is a difference frequency, but objecting to calling it a sub-harmonic? I can see that distinction, because as soon as I shift the frequency of either by a bit, it would no longer appear (to a musician) to be a sub-harmonic (it would not be harmonically related).
We'd need more details of your set up, but I suspect that it was not replicating the effect of the human voice well enough. I don't really understand how the signal generator was being used - you "turned the volume up" - what was the generator connected to, and how?Daniel Petka said:I hear what you are saying, you think that the amplitude modulation should work for any wind instrument, not just one that uses a vibrating membrane.
To find the subharmonic on a flute, I used an external sine generator, because singing might give you a false signal - the subharmonic may come from the vocal chords! I turned the volume way up and tried many instruments that are similar to a flute (glass bottle, wine glass, etc... Helmholz resonators essentially), but failed to find the subharmonic. ...
I think you need the signal amplified, and run to a speaker that is modulating the flow of air to the wind instrument. Just pointing a speaker at it (if that is what you did), might not have the desired effect. I'm thinking something along the lines of a speaker mounted to a closed box, with a controlled source of air running in and out of the box through hoses, to the wind instrument. This, I think, would provide a stream of air that has those 600 Hz (using my earlier examples) variations in pressure, but always positive, so as to keep the air column oscillating.
I'd love to set this up and test it myself, but I have a few other things going on at the moment.