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Home Forums Products Stompboxes Micropitch Pitch knob vs. H910 H949 Pitch knob Reply To: Micropitch Pitch knob vs. H910 H949 Pitch knob

joegrant413 wrote:

… In the H910 H949 algorithm, when I set “Pitch Cntrl” to “Micro”, Pitch A goes from 0.908 to 1.092 for “Pitch A”. The manual tells me that this value is a pitch ratio. Now I’m confused. If this setting is, say, 1.001, is that 0.1 cent above unison? …

It’s 2 different ways of measuring the same thing.  Like expressing temperature in either Farenheit or Celsius.

One way to compare frequency ratios to cents is by switching to the H910 / H949 CHROMATIC mode.  A minor 2nd up from unison rounds to 1.060.  That same semitone would be 100 cents up.  So the MICRO mode of the H910 / H949 algorithm ranges upward to a 1.092 ratio, or about 152 cents.  The downward 0.908 ratio is about -167 cents (down).  A little more than a semitone + a quartertone in either direction.

… And if that’s true, then the H910 H949 would have finer control than Micropitch …

I’d call it a 3X wider range of pitch shift.  You can get even wider by using the NORMAL mode.  It seems to me that the MICRO mode – and MicroPitch algorithm – devote more processing power to pitch accuracy for smaller shifts.  And the frequency ratios to 3 decimal points are roughly twice as coarse as a range defined in cents.

The MicroPitch algorithm can double to 100 cents in either direction [by latching the Flex / Performance switch], and adds LFO modulation for a semi-independent pitch modulation.  The H910 / H949 algo features classic rack unit ‘modeling’, with multiple splicing techniques, and glitching characteristics (or not).  Both can produce similar effects within a narrow range of equivalent pitch shift.

… But that wouldn’t seem right. I suppose it would make a lot more sense to me if this algorithm’s Pitch Cnt was also just straight cents …

Eventide went with historical accuracy for the H910 / H949 algorithm.  Frequency ratio was the unit of measurement used on the original rackmounts.  It’s 12-tone Equal Temperament.  This deviation from unison pitch, expressed as a ratio, can have an equivalent in semitones.  So can a certain number of cents.  I agree that it can be easier to think in cents and semitones.  Frequency ratio and cents can be converted back & forth.