Quote Originally Posted by skeptic
No! He claims the present method is inadequate and gives false results. He postulates that it disguises the true answers. At the very least, he will have to show that nonlinearities in the existing equipment or random noise disguise the actual results using the present method and that his doesn't.

You are not being clear here. Which present method?

If you are talking about single tone HD measurements, this is wrong because a single frequency measurement DOES NOT FULLY CHARACTERIZE THE DUT AT ANY OTHER FREQUENCY. I know that this is not so much the case for RF amps, which operate over a very small % octave basis, but for an audio power amp, which operates over a three PLUS decade range, or over ten octaves, it is indeed the case. This information is in the literature, and has been provided by many a power amp or preamp review. A simple linear equation, such as is used to determine the X order intercept point FAILS with most audio devices.

If you are talking about the prior multitones that were being used by others before I came up with the Phi Spectral multitone, then they were guilty of either a lot of distortion product cover up, or were gulity of a HUGE amount of distortion proiduct cover up (ala the AP FASTTEST signal).

When I state that the traditional single tone HD measurement is not going to be relevant for most audio devices, I am not trying to repeal Fourier or rewrite Laplace, not at all, I am simply looking at the inherent limitations of the existing signals that are currently used.
A single tone HD measurement all by itself does not provide the correct HD information for other frequencies that are far removed from the measurement frequency. A single 1 kHz HD measurement will NOT tell you what the HD is at 100 Hz or 10 kHz, for audio devices, it just isn't so.
When I say that the classic two tone IM signals do not excercise the entire audio spectrum, this is a completely true statement. Measurements taken with the three major classic IM methods will all DIFFER in the levels of distortion they record when used with audio devices. Doesn't this tell you something? It DOES invalidate FLZapped's comments, and renders your sweeping claims that I am trying to repudiate Laplace and Fourier as over the top and irrelevant to the issues at hand.

Jon Risch