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Re: guitarists: triple play?





On 05/01/2015 09:35, Diarmuid Pigott wrote:

My own experience of MIDI from strings is that the detection of vibrato 
and bend and gliss is pretty much
dependant on the MIDI instrument I am using.

I think there's a bit of a miss-conception going around.

The Midi instrument actually has nothing to do with detection,
it only responds to midi commands.
By then the detection is already done.
What *is* important is that the Midi instrument needs to respond
correctly in order to interpret the pitch information correctly.
i.e. the amount of pitch change in response to MidiPitchBend has to be set 
correctly.
That's actually rather trivial to set up, as long as the midi instrument 
supports it.

For a device like the Fishman the situation is a bit different, in that
there may be processing of the audio from the pickup.
In that case it's obviously possible to pass the audio in some form and
get what seems like "perfect tracking", when no tracking has been needed.

For note detection there's an absolute limit that's never going to be 
beaten.
I look at it from a slightly different angle to the usual idea of note 
frequencies.
The impulse from plucking the string has to travel up to the fret and back 
to the pickup
before it's possible to calculate which fret was used.

Using that way of looking at things the Axon system can make a the 
quickest possible
guess at what the note played is, then it uses a more regular analysis to 
measure
the frequency. Should the initial guess be wrong a correction is made to 
the Note-On
that was sent using MidiPitchBend.
As the Axon system is patented then it kind of looks like no-ones going to 
get
faster tracking without licensing it.

Warbling on a sustained note occurs when the fundamental of the note fades 
before the harmonics,
so on some instruments there'll be one or two notes that warble every time.
Just down to the resonance of the instrument.
If the instrument is specially designed to work with midi convertion I 
suspect
they spend a lot of time working removing any 'bad notes'.

If there's going to be any improvement over the Axon system it won't
be in fast detection of the note, but rather in the ability to
keep tracking a note as it dies away.


andy
ps. for playing around, the monophonic devices by Sonuus have somewhat 
slower note
detection but are fairly warble resistant.