in a minimum phase eq, let's say you boosted the treble. does the
treble now arrive before or after the rest of the signal?

I believe any eq tilt or tweak affects the time domain (must always be
*after* - otherwise it's opening up a crude time machine) of that frequency
band relative to the phase of the majority of the remaining audio spectrum.
Can be up/down shelf or bell/notch with a specified Q.
Now, if eq could be invented with no significant phase alteration!
wrote in message
ups.com...
in a minimum phase eq, let's say you boosted the treble. does the
treble now arrive before or after the rest of the signal?

wrote:
in a minimum phase eq, let's say you boosted the treble. does the
treble now arrive before or after the rest of the signal?

If you looked at the steady state cycle to cycle timing of the "treble"
sine waves compared to the input signal, there would appear to be a
phase lead.

However, the ENVELOPE of the output signal cannot precede the envelope
of the input because no filter or EQ can predict the future.

In min phase filters, generally there is an envelope or group delay
where the filter has frequency response slope. There is the seeming
(but not true) contradiction, that the individual sine wave cycles
appear to be advanced in phase, but the envelope of the signal is
actually delayed in time.

So the envelope of the treble arrives slightly later (within 1 cycle of
the treble) compared to the envelope of the bass. We are talking about
on the order of 0.1 ms or less which corresponds to a few inches in air
and is generally accepted as not audible.

Mark

wrote in message
ups.com

in a minimum phase eq, let's say you boosted the treble.
does
the treble now arrive before or after the rest of the
signal?

Depends what you call "arrive".

Systems can't be acausal - they can't have any output until
the input begins.

A minimum phase system with flat response has an output that
commences exactly when the input commences.

Therefore, a minimum phase system with boosted treble can't
have output that commences any sooner than one that has flat
response.

However, if you define arrive as being when a rising wave
reaches say 90% of its final amplitude, the treble-boosted
system will have an output that reaches 90% of final
amplitude sooner.

If you look at a minimum phase treble-boosted system, you
will see the output initially commencing at the same time as
with a flat-response system, but the sloped portion of the
wave will rise more rapidly.

Neither. Its phase now leads the phase of lower frequencies.

The output of /any/ filter cannot precede its input.