Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
References: <email@example.com> <3DC634B7.C303BC8E@scazon.com>
Subject: Re: Bullshit wins v. science
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Date: Mon, 4 Nov 2002 16:34:32 -0000
NNTP-Posting-Date: Mon, 04 Nov 2002 16:34:36 GMT
"John Larkin" wrote in
> On Mon, 04 Nov 2002 08:49:59 +0000, Paul Burke
> >Richard Henry wrote:
> >> There is no point using this unless you upgrade the house wiring
> >> the wiring back to the reactor, I guess) with oxygen-free copper
> >> Did I mention that the power must be 100% from a nuclear reactor?
> >Has anyone researched into which phase of the mains produces the best
> >audio sound? I would guess that the middle phase will be best, as the
> >other two phases are 120 degrees too early and too late,
> >think that recordings should include information as to which phase
> >used for the studio equipment, so we can match it at home.
> >Paul Burke
> Certain instruments do sound different if the audio phase is reversed,
> ie, compression/rarefaction are swapped from the original performance.
> Almost nobody tries to control this.
This is a misconception. The ear is *absolutly* *insensitive* to phase.
A static phase shift is quite undetectable. It is a Fourier analyser.
What you are probably referring to is the effect where if you *add*
*two* signals cancellations and/or additions occur such that the
frequency response of the system is modified.
A typical example is the guitar "Phase Pedal". In this effect a varying
phase shifted signal is added to the unmodified signal. This results is
a surf effect. However, if you simple set the phase to a fixed value,
and do not mix in the unmodified signal, there is no detectable
difference, no matter, what you set the phase shift to. To test this set
the mid control of a decent tone control system to full cut and sweep
its frequency. The effect is essentially the same as that achieved by
phase shifting the signal.
If you *sweep* the phase continuously, you will notice a change. This is
because phase *modulation* is essentially equivalent to frequency
modulation, such that a spread of frequencies will be generated.
Again, note that the humbucking pickup sounds different in phase and out
of phase, because the two coils are being added and subtracted,
generating a frequency response variation.
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