Inverting a single signal

[dangeorge6]

Hey guys,

So today I was recording some vocals, just a single mic going into a single channel of my pre. I pressed the invert switch on the pre and it seemed to sound better. Is this impossible? I always thought the invert switch could aid in eliminating phasing when two mics are used at different distances. Can inverting a single signal help it sit better in the mix or sound better?

Danny

[AdamLazlo]

Originally Posted by dangeorge6

Hey guys,

So today I was recording some vocals, just a single mic going into a single channel of my pre. I pressed the invert switch on the pre and it seemed to sound better. Is this impossible? I always thought the invert switch could aid in eliminating phasing when two mics are used at different distances. Can inverting a single signal help it sit better in the mix or sound better?

Danny

YES!

It's not exclusive to just two mics in one room but also anything in a mix. Frequencies with all instruments at any volume have effect on one-another. That's why you hear people say things like "the drums sounded great solo'd until I un-muted the bass and guitars... all of a sudden (whatever it happen to be) got lost".

It's (sometimes) not a volume thing, most of the time but it can also be a phase issue with other separate tracks. Welcome to the fold... the obsession.... and sleepless nights.

But yet again, you'll find things can only get better from here... then just make sure you're aware of how it translates in mono... that's where the REAL fun begins.

-- Adam Lazlo

[tINY]

Some sources - like male voices - are asymentrical. That means that the average value of the electical signal from the mic is not zero.

If you are working near a rail, or using heavy compression, or have a "colorful" pre amp, then you can definately get a different sound by switching the phase.

Orban had a good white paper on this - look for info on "phase rotator" circuits......




-tINY

[Tim Farrant]

Tiny, ALL real audio signals are asre - y - metrical, come on !!!

If you are listening to the source on it's own with no other sounds, then swapping phase will change the direction of the loudspeaker cones. The + signal that did push the driver forward is now pushing the driver backwards. This alone can change the sound. Loudspeakers are ancient technology, we all assume that they reproduce +/- signals the same - not so I am afraid to tell you.

Just when you thought it was safe to go back into the water....


Tim.

[Yiannis]

almost the same happend to me guys

Strange problem!!

[doorknocker]

Originally Posted by dangeorge6

I always thought the invert switch could aid in eliminating phasing when two mics are used at different distances. Can inverting a single signal help it sit better in the mix or sound better?

When I mix in PT, I always put a Trim plug-in on most channels just to check if inverting the phase does anything and it often does.
Sometimes it's a sort of fata morgana thing and not really audible when playing a test mix outside of PT.

For me it's the same as with shifting tracks. Very ofte I find that putting a tiny bit of delay on say a bass track (or shifting it but I prefer the Digi delays set to 100% wet and no modulation/regeneration) will make it sit so much better in the mix.

I guess it's often just a happy accident but that's o.k.

When dealing with 2 mics on the same source there's only one solution for me though: The Little Labs IBP, a most amazing tool!

[tINY]

Originally Posted by Tim Farrant

Loudspeakers are ancient technology, we all assume that they reproduce +/- signals the same - not so I am afraid to tell you.
.

Let's not go down this road again. You remember my experience with phase on the playback speakers......



-tINY

[Ethan Winer]

Tim,

> Loudspeakers are ancient technology, we all assume that they reproduce +/- signals the same - not so I am afraid to tell you. <

That's the right answer. We can't hear absolute polarity, but we can hear it when the speaker responds differently for each direction. So it's the speaker's difference in nonlinearity we hear, not the absolute polarity itself. At least that's my experience.

--Ethan

[Yiannis]

Originally Posted by doorknocker

When I mix in PT, I always put a Trim plug-in on most channels just to check if inverting the phase does anything and it often does.!

I have noticed the same!!
Could someone please explain why this is happening?

[max cooper]

Originally Posted by Yiannis

I have noticed the same!!
Could someone please explain why this is happening?

I thought the whole thread was kind of the explanation for this.

[Yiannis]

Originally Posted by max cooper

I thought the whole thread was kind of the explanation for this.

all I can understand from this treat is that this is a phase issue.
But I don't get,why this is happening and what people do to avoid it!

If you have 48+ tracks to mix how can you find if you have phase issues on some combination of the tracks?

There could be a lot of track combinations to look for

[Sizzleboy]

Originally Posted by Yiannis

all I can understand from this treat is that this is a phase issue.
But I don't get,why this is happening and what people do to avoid it!

If you have 48+ tracks to mix how can you find if you have phase issues on some combination of the tracks?

There could be a lot of track combinations to look for

What the thread is saying is that a loudspeaker cone is not an accurate device for producing a sound wave. It sounds different pushing air than it does pulling air. If you have a single noticibly assymetrical signal (like a drum hit, a horn, or a lower register vocal) the leading edge of the transient will sound different whether that speaker is starting off by pushing the wave, as opposed to pulling it.

What you are talking about is phase correlation between multiple signals, which is something entirely different.

[tINY]

It's true that speakers are non-linear. But, until you get close to the excursion limits, you shouldn't be hearing a difference.

Besides, even if you could, the kid listening to your work on his I-pod may have the phase reversed and most ear buds are awful at any level....



-tINY

[zilver]

Is this not the " voice sounds different while singing with headphones on because of the blending with head resonance " thing ? The signal on the headphones mixes well/not so well -phase wise- with the voice you hear directly.

That's a very noticable effect (Just try speaking with headphones on at both sides of a fig of 8 mic).

Hans

[danasti]

This is your friend...

http://www.littlelabs.com/ibp.html