Phase. What exactly is it?

[Barryw]

Originally Posted by Electriclight

Exactly,
that's why some arbitrary 3:1 rule makes no sense.

...After creation, I don't think a 440 Hz wave will ever be in phase with a 12360 Hz wave except on rare, essentially random occasions.

No, the 3:1 rule doesn't try to find a placement that will get signals in-phase... it just helps assure that the signal from the distant mic is so much lower in amplitude than the close mic that the phase differences tend to not be highly disruptive.

If both signals are at about the same level, and out of phase, they can cancel each other out. But if one mics signal is only 10% as strong as the other, even if it is out of phase, it's not strong enough to impact the close mics signal... very much.

-Barry

[brandondrury]

With all the various frequencies being emitted, how can you find an actual sweet spot? After creation, I don't think a 440 Hz wave will ever be in phase with a 12360 Hz wave except on rare, essentially random occasions.

Another side to that is if the tone picked up by the distant mic is different enough from the close mic (which is really the point) than even if there are some phase issues, it will become irrelevant. I'd say this happens more with a mic @ 3' and 9' than mics at 3" and 9" or 1" and 3".

My main quams are when we try use multiple mics at the same distance from the source. All hell can break loose.

Brandon

[Audio~Geek]

The 3:1 rule/principle is the one of the most widely misunderstood concepts in recording.

I can say something like "3:1 rule does not apply to stereo miking techniques", and 33% will agree and 33% will vehemently argue, and 33% will have never thought about it.

see here:
Question about the 3:1 principle - The Womb
and
Tape Op Message Board :: View topic - Question On The 3:1 Theory


Really the bottom line is, check in mono for phase problems, using your EARS!

[Audio~Geek]

To save all the reading I'll condense both threads into one quote.

Originally Posted by Weedywet

3 PARTS GIN
1 PART VERMOUTH

[brandondrury]

For those who really want to learn about this phase crap, I have a chapter in Killer Home Recording entitled "The Worst Chapter In This Book". It was incredibly difficult to write AND keep it down to Earth so it doesn't sound like Niel Bohr Niels Bohr - Wikipedia, the free encyclopedia wrote it. However, I'm convinced that it's thorough. I think pretty much everyone will "get it" after reading it.

Brandon

[mindundermatter]

Definition of 'Phase' as taught by one of my professors in college (he made us memorize it so we would wake up in the morning thinking about it): The position of a wave relative to the completion of it's cycle.