On 06/26/2011 10:50 AM,
pshirkey(a)boosthardware.com wrote:
> Other than that, I'd make a really cool
spectrum analyzer that ran the
> Fourier analysis on two channels, correlated their phases then made a
> +/- line vs. frequency for all to see so that the phase of the
> components of the spectrum could be watched for phase relationships.
that is precisely what dual-fft tools for p.a. system calibration do,
and they're extremely useful.
they allow you to constantly monitor the system with _program_ material,
without having to use MLS noise or any other specific measurement
signal. one channel is used for the direct signal from the mixer, the
other is fed by a measurement microphone with delay compensation. you
get instant phase and amplitude response. good systems also give you an
additional "confidence" curve that tells you how much you can trust
which parts of the spectrum. for instance, if your program material is
a boy soprano, the confidence of the measurement in the low end is
practically zero.
I use(d) japa for this :-) Altough that lacks phase display...