[Scott Dorsey]

James Price wrote:
We're now talking about two things, one of them is keeping stuff in
phase in general. The other, you're asserting that frequency remains constant.
Yes, you can get something perfectly in phase but it will change as soon as
the frequency content changes. Do we agree on that?

No. You can add distortion products, but the original stuff is still there
and the phase relationship between them is not changed just by adding more
components. There is no magic going on when you add distortion products.
Try it. Look on a scope.

As for injuring the phase relationship, isn't that what it's intended for? When I'm summing multiple mics, there's no issue. Add the DI from an amp and it comes into play.

Oh, there can be issue with summing multiple mikes too if there is leakage
into them..... and it's for the same reason that it's an issue with the DI...
with the DI you have a microphone feed and a direct feed and they are shifted
in time by a couple milliseconds. When you sum them together, you get comb
filtering.

But it is the comb filtering that is audible, not the delay.

We may be getting on the same page here. I never said delay wasn't an issue.
I'm saying I don't think it's the only one.

ALL PHASE SHIFT IS DELAY.
Some of it is delay that is constant with frequency.
Some of is delay that is not constant with frequency.
but it is ALL DELAY.

Delay isn't an issue. Group delay isn't an issue. What is an issue is when
you sum signals that are shifted in time together and get comb filtering.
It's the _comb filtering_ that is the issue, not the phase shift.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."