Correct way (if there is one) to mic with 2 mics

[::XeS::]

Hi
As the title says, I would like to know if there is a correct way to mic with 2 mics a guitar cabinet.
Usually I use only one mic or, if I use 2, I put them at the same distance from the grill cloth both on axis (one aiming the junction and one aiming the center of the cone mainly).
Is there a correct relation for the distance between the 2 mics and the distance between the grill and the mics?
Don't know....some 2:1 or 3:1 rule for example. Sometime ago I read here that someone put one mic at 1inch from the grill and the other more distant, like 2 inch from the grill...
So...let me know

 

[AudioPhile777]

The correct way is always the way that sounds the best... there is no other guideline than that... experiment.

Have fun.

 

[::XeS::]

Yeah of course... I mean, perhaps there could be some rules to avoid phase cancellation etc... I know the best placement is the one that sounds better. But sometimes there are some cool tips

 

[BLUElightCory]

The easiest way is to line up the mics so that the capsules are the same distance from the speaker. This way the sound is hitting each mic at the same time, which will minimize any phase problems.

Another way is to position each mic so that it sounds best on its own and use a phase-alignment tool (such as the Little Labs IBP) to tweak the phase relationship.

Still another method is to say "screw the phase" - position the two mics where they sound good and use phase to dial in your tone : different blends of two mics that aren't perfectly in-phase can yield TONS of different tones and voicings, sometimes you can hit on something that sounds truly great.

 

[ahjteam]

I mean, perhaps there could be some rules to avoid phase cancellation etc...

Dual micing is based on phase difference.

 

[::XeS::]

Ok thank you for the answers

 

[lucaskills]

Hi,

this could probably help you to find some starting positions.

d=n*l (distance = n * lambda (wave length)) for n you can choose: 1,2,4,... the phasing is "identically" at each mic.

to get the wave length simply type your numbers in here:
l=c/f (lambda = particle velocity (just use 340 m/s / frequency)

Lets get a simple example of this:

You want to mic an instrument with 2 mics and you want some room on the second mic. The main frequency is 450hz (just for e.g.)

first step: get wave length
l= 340/450 -> 0,75m

second step: position for your mic
what you get out of this is, that you now have to position your second mic 0,75m away from the first mic. if you want more, just use the first equation and change n.

REMEMBER, THIS IS JUST IN CASE YOU WANT TO MIC SIGNAL + ROOM WITH THE SECOND MIC.

If you want it to be dry, use close micing.

Sorry for my bad english.

 

[Trevoire520]

Dual micing is based on phase difference.

+1, the whole point is basically to use phase cancellations to your advantage to cancel out frequencies that you don't like.

Sure you can align the capsules but at the end of the day the phase is never going to be perfect.

I've read on here about guys that throw up their first mic wherever they would normally single mic, then throw up their second mic with the phase flipped (make sure the gains are matched) and sweep the second mic listening for the horriblest, nastiest, fizziest, thinnest, shittest tone you can. Lock the mic down and then flip the phase back to normal and things should be nice and beefy.

 

[lucaskills]

Sure you can align the capsules but at the end of the day the phase is never going to be perfect.

Absolutely. As i said, use this equotations just to get a starting point.

 

[AudioGeekZine]

Put first mic where it sounds cool.
Put on headphones and add in the second mic. Invert the polarity of the second one. (Keep both panned center)
Move the mic around. You want to put the second mic where there is the MOST cancellation.
It can be hard to set this up on your own. If you can see the meters in the DAW you'll have the master lower when they're mostly out of phase.
Invert the polarity again (normal now)
Big sound!

 

[::XeS::]

Great tips...I'll try them next time
Thank you so much

 

[ze kink]

I've read on here about guys that throw up their first mic wherever they would normally single mic, then throw up their second mic with the phase flipped (make sure the gains are matched) and sweep the second mic listening for the horriblest, nastiest, fizziest, thinnest, shittest tone you can. Lock the mic down and then flip the phase back to normal and things should be nice and beefy.

This is what I've usually done when I've used two mics. Whenever I've added a more distant condenser though, it's always felt futile so I've just went with what my ears tell me. Lately I haven't bothered with doing the phase flipping thing though, I've just thrown the mics and if it sounds shit, I've moved them around a bit.

 

[AHChris]

Put first mic where it sounds cool.
Put on headphones and add in the second mic. Invert the polarity of the second one. (Keep both panned center)
Move the mic around. You want to put the second mic where there is the MOST cancellation.
It can be hard to set this up on your own. If you can see the meters in the DAW you'll have the master lower when they're mostly out of phase.
Invert the polarity again (normal now)
Big sound!

this!

The easiest way to do this is:

1. Turn your amp on, switch to the distorted channel and turn the gain and volume up until you can hear a decent amount of white noise going on.

2. Put your two mics in front of the speaker and turn your mic preamps to eleven.

3. Flip the phase on one of the preamps.

4. Grab your good isolation headphones, bring one mic into position. Then move the other mic until the white noise gets very thin and almost disappears on your headphones.

5. Flip phase and have phooooon!

 

[mva801]

Here's how i usually double mic a cab:

I have about a 6" length of guitar string with a little piece of tape on the end. I insert that through the grille cloth, where the Cone and dust cap meet. I align one mic on one side of the dust cap, and the other on the other side of the cap. By using the little measurement tool, i can align the diaphragm of the mics near perfectly from a known point on the speaker. In phase every time.

My favorite combo lately has been a royer 121 and either a 57, audix i5, 421, or SM7. I find the royer gives a ton of body and thickness to the sound. You can get widely different sounds just by riding the fader of each mic independently.

And if I'm not happy with that, I'll bag the whole thing and just move shit around til it sounds good!

 

[John_C]

Hi,

this could probably help you to find some starting positions.

d=n*l (distance = n * lambda (wave length)) for n you can choose: 1,2,4,... the phasing is "identically" at each mic.

to get the wave length simply type your numbers in here:
l=c/f (lambda = particle velocity (just use 340 m/s / frequency)

Lets get a simple example of this:

You want to mic an instrument with 2 mics and you want some room on the second mic. The main frequency is 450hz (just for e.g.)

first step: get wave length
l= 340/450 -> 0,75m

second step: position for your mic
what you get out of this is, that you now have to position your second mic 0,75m away from the first mic. if you want more, just use the first equation and change n.

REMEMBER, THIS IS JUST IN CASE YOU WANT TO MIC SIGNAL + ROOM WITH THE SECOND MIC.

If you want it to be dry, use close micing.

Sorry for my bad english.

Urm..........sorta.......only not really

that's all very well for a test tone but not really any use for music.

 

[slashvanyoung]

This is what I've usually done when I've used two mics. Whenever I've added a more distant condenser though, it's always felt futile so I've just went with what my ears tell me. Lately I haven't bothered with doing the phase flipping thing though, I've just thrown the mics and if it sounds shit, I've moved them around a bit.

Yes, I used to do the phase flipping too but nowadays I'll often freely move the mic to find a sweet spot.

One mic always gets positioned to sound great on its own though (usually a 57) so that completely ditching the second mic is always another option. I guess positioning the first mic to sound best on its own is the most common thing anyway.

What I sometimes like to do is to nudge the track of the second mic back or forth a few ms in the DAW to experiment with different phase-characteristics.

 

[lucaskills]

Urm..........sorta.......only not really

that's all very well for a test tone but not really any use for music.

It seems you guys get me wrong all the time.

I meant this tip as a starting point. Going from nowhere can bring you results but if you have background on how the signal behaves, you know which range the mic has to stand.

 

[John_C]

It seems you guys get me wrong all the time.

I meant this tip as a starting point. Going from nowhere can bring you results but if you have background on how the signal behaves, you know which range the mic has to stand.

yes, i agree that 0.75 metres is a good starting point for micing up a 450Hz test tone, but what about a 375Hz test tone................oh wait suddenly we need a very different distance....
A fullrange distorted guitar = omg i need my mic to be everywhere at once

 

[lucaskills]

yes, i agree that 0.75 metres is a good starting point for micing up a 450Hz test tone, but what about a 375Hz test tone................oh wait suddenly we need a very different distance....

Thats what i wrote. Get the distance from the equotations.

A fullrange distorted guitar = omg i need my mic to be everywhere at once

Def. on your side here. But to get a slightest idea of an area you want to put your second mic you can still go with this tip. And guitars also have typical main frequencies that can be defined.

 

[MarcusGHedwig]

And guitars also have typical main frequencies that can be defined.

Clean guitars maybe; heavily-distorted with a ton of harmonic content? I doubt it