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Captain Whisky
New member
Good lord, what have I done? 
haha
haha
D
drtechno
Active member
so how does it sound panned apart from each other?
it does look like between 45-90 degrees most likely a sideways pointing mic about 2 feet from the other mic
if it works it works.
it does look like between 45-90 degrees most likely a sideways pointing mic about 2 feet from the other mic
if it works it works.
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Captain Whisky
New member
You asking me about the recording from my first post? I wouldn't say it's as much as that, it's a very minimal phase difference. I recorded it ages ago so i can't remember exactly how I miked it up.
ashcat_lt
Well-known member
I am absolutely positive that the OP is 90 degrees out of phase. It's also 180, and 540, and 62, and 12, and any other damn number you'd want to throw out there! Give me the exact delay time and the Temp, Humidity, and Pressure at which it was recorded and I can find a frequency to match any phase angle you want to mention.
bouldersoundguy
Well-known member
Tracking acoustic guitar and vocals at the same time would be one case, or two acoustic instruments or two vocals etc.
bouldersoundguy
Well-known member
What you're seeing is a difference in arrival time. Phase is relative to frequency and there are lots of frequencies at the same time, so it makes no sense to throw out numbers like that.
G
Greg_L
Banned
Nope.
ashcat_lt
Well-known member
If you're using mics with sensitivities very close to the same with exactly the same preamp gain AND you can set the faders at exactly the same levels without adjustment and get a decent mix, it might help.
Otherwise, what Greg said.
M
mixsit
Well-known member
Huh? What is the point you (or Greg) are trying to make here? Presumably that the numbers, or ratio' are no good or won't apply because or unless these 'conditions exist? Maybe I'm misunderstanding. The only thing of use to get out of any of this is to understand the underlying principals, knowing why unwanted cross bleed is doing what it does, and knowing what you can do about it; Get your -9db or what ever if you don't have to have to hear it..
bouldersoundguy
Well-known member
Similar source SPL and similar overall gain are all that's needed. And those can be stretched somewhat by increasing the ratio and/or using directional mics.
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Greg_L
Banned
My only point is that these archaic recording rules and regulations are stupid, and worrying about them is even stupider because the "rule" can be broken over and over with awesome results. I personally don't care if anyone whips out a tape measure to set up mics. I just know that it isn't necessary.
Steenamaroo
...
Course it's not necessary. You implement the 'rule' instinctively.
Farview
Well-known member
Ashcat and Greg are correct. These rules of thumb were established when bands were recorded in the same room with similar mics. There is nothing magical about the 3 to 1 rule that fixes phase issues, it is just the distance that will create a 9db difference between the mics, which minimises the effects of the phase difference. It doesn't change the phase difference at all, it simply diminishes the effect.
As long as one Mic signal is at least 9db quieter than the other one, you will not have phase problems. How you make that happen is up to you.
You can:
1. Use the 3 to 1 rule to place the mics and keep them at equal gain (not equal volume at mix time, equal gain)
2. Record one of the mics at least 9db quieter than the other.
3. Mix one of the mics at least 9db quieter than the other.
4. Decide that the comb filtering effect sounds cool and leave it alone.
5. Pan the mics away from each other to create a stereo effect.
There are probably others that I can't think of at 7am, but those are the obvious ones.
The concept of the 9db difference is much more important to understand than the 3 to 1 rule, because the rule is just one way to make that happen (under the right circumstances)
As long as one Mic signal is at least 9db quieter than the other one, you will not have phase problems. How you make that happen is up to you.
You can:
1. Use the 3 to 1 rule to place the mics and keep them at equal gain (not equal volume at mix time, equal gain)
2. Record one of the mics at least 9db quieter than the other.
3. Mix one of the mics at least 9db quieter than the other.
4. Decide that the comb filtering effect sounds cool and leave it alone.
5. Pan the mics away from each other to create a stereo effect.
There are probably others that I can't think of at 7am, but those are the obvious ones.
The concept of the 9db difference is much more important to understand than the 3 to 1 rule, because the rule is just one way to make that happen (under the right circumstances)
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moresound
Loud Sun Studios
Now this has been an interesting read. 
M
mixsit
Well-known member
And it's interesting that we're in agreement then in that it doesn't matter how you get there. But it is the underlying principle is where the value of it is. It seems odd to me so much made over what it's called, maybe it's the 'rule part of it? Ok. It's flexible. There's variables.
But this 'it don't apply to so and so ..because of ..what was that again now?
miroslav
Cosmic Cowboy
You guys still working on the math?
Yeah, that's the thing...how people are recording and who/what they are recording.
I think in the home-rec world, some considerations are either ignored or just not always applicable when comparing to what happens in more typical commercial recording.....but certain "rules" and/or audio "standards" still apply, though I think they are not always as critical or paid attention to, in the home-rec world, since most of it happens in bedrooms, garages and other less than ideal recording environments anyway.
I agree...it's a rare thing to whip out a tape measure in the home-rec world and worry about that stuff....though, even when working solo in the home studio, sometimes it can come up.
I haven't had to measure mic distances in ages, but just a few weeks ago I wanted to record my upright piano in stereo, and I wanted the lower octaves to be pretty isolated from the upper, so I "roughly" measured out the space between the two mics relative to the piano at the bottom of the soundboard....and that worked out well to isolate the lower octaves on the Left from the upper octaves on the Right, since most of the playing was going to be either low or high on the keys.....then I added a third mic up above the piano at the middle of the keyboard to use for balancing things out so there wasn't a "hole" in the middle.
The mics probably could have been placed just "by eye"....but I took out the tape measure just to confirm that I had at least a 3:1 distance ratio....and I wasn't worried about "phase".....but moreso about bleed.
Yeah, that's the thing...how people are recording and who/what they are recording.
I think in the home-rec world, some considerations are either ignored or just not always applicable when comparing to what happens in more typical commercial recording.....but certain "rules" and/or audio "standards" still apply, though I think they are not always as critical or paid attention to, in the home-rec world, since most of it happens in bedrooms, garages and other less than ideal recording environments anyway.
I agree...it's a rare thing to whip out a tape measure in the home-rec world and worry about that stuff....though, even when working solo in the home studio, sometimes it can come up.
I haven't had to measure mic distances in ages, but just a few weeks ago I wanted to record my upright piano in stereo, and I wanted the lower octaves to be pretty isolated from the upper, so I "roughly" measured out the space between the two mics relative to the piano at the bottom of the soundboard....and that worked out well to isolate the lower octaves on the Left from the upper octaves on the Right, since most of the playing was going to be either low or high on the keys.....then I added a third mic up above the piano at the middle of the keyboard to use for balancing things out so there wasn't a "hole" in the middle.
The mics probably could have been placed just "by eye"....but I took out the tape measure just to confirm that I had at least a 3:1 distance ratio....and I wasn't worried about "phase".....but moreso about bleed.
Farview
Well-known member
The 3 to 1 rule is only about bleed. It never did anything for phase, other than minimise the effects of comb filtering by minimizing the bleed.
ashcat_lt
Well-known member
Be careful there. We're talking about the interaction of one source in two mics. So as long as that one source is 9bd quiter in one of the mics (and presumably the other source is 9db quieter in the other mic)...
One important thing you left off your list of options is polar response - of the mics especially - but also that of the sources. If the mics or sources are directional, you can use that to get the volume difference too.
I've also seen the 3:1 thing mentioned re
lacing stage monitors to avoid creating a phasey mess around the performer's head.
M
mixsit
Well-known member
A wise man once said..
Someone had mentioned the ac guit + voc earlier. (wait, do home recordists do that? Ok
There's a real common one where bleed is a PITA situation. With a pair of cardioids you can't (typically) 'solve it with the physical layout of it with placement so much, but a pair of fig 8's'll do you your '9db' and more.
Ding!
Someone had mentioned the ac guit + voc earlier. (wait, do home recordists do that? Ok
There's a real common one where bleed is a PITA situation. With a pair of cardioids you can't (typically) 'solve it with the physical layout of it with placement so much, but a pair of fig 8's'll do you your '9db' and more.