I've digitally re-equalized 78rpm discs by reversing the RIAA eq. and introducing a new equalization curve. The phase shifts that would have been caused by a proper analog playback are not reintroduced due to the known limitations of the software. I have never been able to detect the distortion. I'm wondering if anyone else has noticed any marked difference?
"Steven C. Barr" <stevenc@xxxxxxxxxxxxxx> wrote:
----- Original Message -----
From: "Dave Bradley" 
> Um. I'm confused. Since EQ is accomplished by the actual shifting of
> phase, how could the phase shift be quite low and have it still be an
> effective EQ?
As I understand it, equalization (or any variance in signal levels produced
by
selective frequency filtering) does not specifically and intentionally
accomplish its goal via phase shifting...rather, the fact that this
filtering
is accomplished through reactive elements in the circuitry (inductance and
capacitance) inevitably produces phase shift as a side effect.
This brings up an interesting point, which would necessitate more knowledge
of
theory than I posess. If equalization is accomplished through digital
simulation
of the produced wave rather than through the introduction of
 reactive
elememts,
is there any "phase shift" of the resulting digital signal?
Steven C. Barr