[pianotech] ETD stretch vs pure (octaves)

[Ron Nossaman]

Duaine & Laura Hechler wrote:
> This may seem like a silly question but ....
> 
> At least Cybertuner has stretch factors built-in. Do you aural tuners do
> stretch factors?

By listening, with interval checks - aurally.


> How do you tune "pure" octaves with a "stretch" factor - this seems
> oxymoronic.

A "pure" octave *is* stretched at the fundamental, even with 
no discernible beat because you aren't aurally comparing 
fundamentals. You're comparing 1:2, 4:2, or 6:3 partials to 
determine stretch. All sound acceptably pure, and each is 
stretched to a different degree.
Ron N