Flipping phase on vocals in the mix

[Marc Alan Goodman]

[Andy Peters]

[Seditionary]

also -- a good test is to solo the vocal. if it has more low end with the phase flipped... might be out of phase in the first place. if it has less low end with the phase flipped... well then you are flipping it out of phase.

is it possible you are using some gear that is 3 pin hot? we had a lot of 3 pin hot gear i found and had to modify to be 2 pin hot to not flip the phase. you might be compensating for something else going on in your chain?

cheers.

[ashcat_lt]

[Seditionary]

whichever position has most low end is the one that is in phase. if the sound is thin... then you can assume the polarity is not correct.

mic test --

take a 2nd mic that works -- move it next to the mic you are wanting to check phase on. put both mics together so that their capsules are touching and speak into them. try to give them equal gain / volume on the preamps. then flip the phase on the mic that you are testing for phase. choose the option that gives you the most low end. whichever position sounds like it has the most low end is the position that is in phase. that is one sure fire way to hear it.

if you want to do a phase test for the actual chain (mic excluded) -- record a synth or sine wave, etc through a preamp and/or cabling you know to be 2 pin hot... then pass it through the chain that might be out of phase... zoom in on the waves, match them up, and see if they changed 180 degrees or not. if the valleys turn into peaks, something in the chain is out of phase.

[dfuruta]

[Seditionary]

Yeah, if you can't tell a difference, you should use a second reference mic to check phase. Put the capsules together... Described in my post above

[vvv]

Hmm, just corresponding with a English friend, ...


... I wonder if the OP meant "that flipping phase" ...



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vlayman; THD; blog; TFP

[farview]

[ashcat_lt]

Yeah. If there's one vocal on through one mic on one track then flipping polarity should make no difference as far as overall frequency response. That's a period.

There might be a very subtle difference in the "impact" of the transients. I find it very questionable, but people say they can hear it.

But there's the question: is it really just one vocal on one track? Is there ant parallel processing happening in this mix? If the polarity flip happens post send (not sure why this would be, but I've never tested my DAW for that. Have you?) it could make a noticeable difference when the effect is mixed with the original. Also, if there is parallel processing with un- or poorly compensated latency then polarity flipping could also make a major difference.
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it only hurts if you let it...

[vxboogie]

[dfuruta]

It also might be worth pointing out that, on some instruments, the "correct" polarity isn't obvious. For example, are you sitting in front of or behind the drum kit? Should the kick (& snare & toms) start with a rarefaction if you pan things drummer perspective?

I can't hear the difference in isolation anyway...

[Chris_Meck]

I use the polarity flip trick a lot in live sound, usually when stage volume is proving difficult for me to get the vocals out front. I don't exactly get HOW it works, but a lot of the time, flipping the polarity on the lead vocal will make it pop right out front without turning it UP.

It doesn't ALWAYS work, but it USUALLY works. it can also work with a particular instrument that's a lower than ideal signal.

I know it's a different situation than the OP is bringing up, but maybe it's related.
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greetings from Flyover Country...

[Nick Sevilla]

One thing on "absolute" phase, not to be confused with polarity.

Usually, when you strike an instrument, or excite it into making the sound, it wil normally have some part of it which moves, and its' movement causes the air on its' surface to move away from the instrument, which is what we call the "sound" transmission.

Typically, whatever this initial mechanical movement IS, we want the speakers at the final end of our signal chain to move in the SAME direction.

So, imagine a drum skin, which when struck by a beater, moves outwards away from the beater, away from the foot which struck it. This is looking at the drum skin from in front of the kit.

We would call this initial movement the initial excitation phase of that drum skin.

If we are to use this drum skin in a traditional musical mix, we would imagine this drum skin to be in the imaginary "front" of the listener, and we would make sure that the speaker reproducing this sound will move in the SAME direction when the electrical signal reaches it, matching that absolute phase of the insturment.

In contrast, if an instruments' initial mechanical movement is AWAY from the intended listener, then we would expect the speaker to move again, in the same direction of the mechanical movement which created the sound.

Now for the fun, very simplified explanation of Polarity in an electrical wire:

Polarity has to do with the ELECTRICAL properties of a balanced electrical signal travelling through a balanced wire, such as we have in an XLR 3 pin cable. In a system, we typically decide to assign pin 1 to ground, pin 2 to "hot" or positive voltage swing, and the pin 3 to the negative voltage swings. These two voltages, although are complete waves within the wire, are only used to allow a longer cable run, by splitting the positive and negative portions of the original waveform, into two polar opposite voltages, which travel at the same time down the wire, and reject RF inteference which may exist in the air around the wire. The two voltages are usually half the amplitude of the original signal.
Once these two polar opposite signals reach the mic preamp, they are again combined and sent down, combined back into the original signal and amplitude, then amplified within the preamp as much as necessary for further processing. Typically the reconstructed signal is turned into a DC signal flow, with only a voltage wire and ground, for most applications, which allows for very small components to process it to be used. Like our modern transistors.

As you can read from the above, Polarity has nothing to do at all with the sound itself, it is only concerned about what voltages are going down a wire.

I hope this clears some misconceptions on what is going on.

Cheers
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The Song. Nothing else really matters.

[dfuruta]