Quote Originally Posted by pos View Post
Hi Barry

What metric are you referring too? Is it related to his polar map tool?
IIRC I once read Earl Geddes state that he preferred to rely on magnitude/phase measurements rather than waterfalls and such, as he found they provided just as much info when properly analyzed.
Hello Thomas;

If recall correctly Dr Geddes has interest in the phase relationship of the higher harmonics with the fundamentals? I do. This is where for instance if a diaphragm is ringing, the sound is no longer correlated with the fundamental and is just noise. This is what we see with the diamond surround drivers. The extra HF is not signal correlated, its energy seen in many frequency domain measurements is energy dispersed in the time domain.

Richard Heyser spoke about this and gave is the tools to measure this in the late sixties I think or early seventies.

I hope we get somewhere on this.

All my best.
Barry.