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SoundLab TDS:DisplayMenu =
:
DisplayoptionsFrequencyFlesponse...
HeyserSpiral
The amplitude of a complex waveform is the result of
two factors called the real partand the imaginary p^rt.
Inaplane progressive wave in the free field (i.e., before
reflections occur) the real part is proportional to
potential energy and the imaginary p^rt is proportional
to kinetic energy.
The amplitude is equal to:
Amolitude
=
2
^ l
2
V(real part) + (imag. part)
and the magnitude is Magnitude =
Magnitude
=
10 log V(real part| + Qmag.part)
The phase response can be found by
Phase="r.t"r,
(H+#)
The Heyser spiral reveals that amplitude and phase are
simply two different viewpoints of the same event.
'S(hy
measure phase?
\a
a
Phase is a more sensitive parameter to find the
center frequency of filters.
Phase reveals driver displacement, something
amplitude can only do very coarsely. (i.e.
inverse square law) whereas phase can show
minute fractions of an inch.
Phase is a clear detector of polarity.
Phase reveals non-minimum ohase behavior.
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