Paranoid about PHASE

[mattkw80]

Question :

Can tracks be 'just a little bit' Out of Phase with each other.... or is it pretty much black and white?

My brother's and I took about 4 hours today, to mic the drums in all the different configurations we could possibly think of. Kind of a neat project, with really varied results.

SETUP 1. x2 Audix F15's using Recorder Man setup

(This was by far, the best results)

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SETUP 2. x2 SM57's using Recorder Man setup

(Also good - darker than the Audix F15's, less high end, but useable)

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SETUP 3. x2 Audix F15's out front of the kit, X/Y config.

(Sounded trashy, not very useable - maybe was reflecting off the back drywall behind the drum kit)

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SETUP 4. x2 Audix F15's out front of kit, but spread wide, 110 degrees or so

(A little better than the X/Y but still bright and trashy - again, maybe becsue now I'm pointing at the back wall, where as the recorder man method in Step 1 NEVER points at the back wall).
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SETUP 5. "All 8 inputs"

1 - Audix D6 Kick
2 - SM57 Top of Snare
3 - SM57 Bottom of Snare
4 - Audix F15 High Hat
5 - SM58 Top Tom
6 - SM58 Floor Tom
7 - Behringer B-1 Right Room Mic / Overhead
8 - Rode NT2 Left Room Mic / Overhead

*I matched the Behringer B-1 up with the Rode NT2 as overhead pairs, because I didn't have another NT2, and the B-1 I believe is just a Rode NT2 knock off anyway.

(This sounded really good. Had to phase invert the bottom snare mic - which I think it pretty standard. We all still favored SETUP #1 to this, in several blind tests we did.)
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Sorry to make a long post, but I have to explain all this to properly ask my question.

With Setup #1, which sounded the best, I would like a little more control over the KICK and SNARE after it's all said and done. But the recorder man method is measured out in such as way, that you should not have any phase issues, and I'm worried that adding a snare mic and a kick mic could throw the entire thing out of whack.

My second question is in regards to setup #5.

Obviously the bottom snare mic was out of phase with the top snare mic. But does inverting the phase not then potentially put it out of phase with say, the high hat, or the kick drum - which bleed into that mic quite a bit considering it's close location to both of those things ?

When I run those 8 tracks of drums, is it possible that each track could be slightly out of phase with the next one?

Can I use a plug-in of somesort or metering to be really sure?

[bennychico11]

okay, yes, phase. I love this topic.

First off, yes I will say you are being very paranoid about it. Phase is something you should keep in the back of your head, but not something you should worry so much about. You don't want to spend hours and hours mic'ing a drum set to avoid phase.

Phase is unavoidable. It's a natural thing in everyday life. You'd be surprised how much phasing is going on around you right now. It's impossible to avoid. So yes, it is possible that tracks are just a little bit out of phase with each other. It happens all the time. Whenever you record several guitar parts or mic more than one instrument in the same room. EVEN if you record just a single instrument...there is phasing going on in the room the musician is in!! This is why we worry so much about room acoustics. Normal phase just introduces a new tonality to your recording. This is what we consider "good" phase. We like it when two instruments are mixed together and form a pleasant tonality. It's when frequencies are being subtracted TOO much that it really bothers us. We get a weird sound that takes away from the recording....this is BAD phase.

The next step after BAD phase is a delay. Remember, all that phase relationships are is just a delay in the audio signal. It's arriving late to a microphone. So the way to avoid phase is to either a) make every microphone the same distance from the source or b) point the microphone so that only ONE source gets recorded.
This is done by utilizing the natural response of a microphone. Cardiod mics (and numerous others) are effected differently to sounds that originate off axis. You can use this to your advantage. Point a microphone so that it only captures the sound it's pointed at.

In the end it comes down to your ears. You are so worried about adding the kick and snare to the mix that you've come here asking about...but have you tried it yet? Things aren't going to blow up if you all of a sudden add those tracks to the mix. Do it and see what it sounds like. First of all, most phase relationships can be corrected with a polarity/phase inversion or delay compensation. Second, you might find that the kick mic wasn't even picking up any of the other instruments. It's very rare that the kick mic actually picks up anything of importance from the snare/HH mic. Not only because of it's distance from those mics, but also because the rhythm of a kick versus the snare/HH are usually nowhere near each other. In other words, usually they hit on different beats, so using a simple gate would take care of anything like that. Hell, the frequency differences are so extreme that I wouldn't ever worry about them. It's not until you start talking about top/bottom snare mics and the overheads that you really need to worry.

Again, keep phase relationships in the back of your mind, but don't worry too much about it. Know what it sounds like, though. So that when you come across it you can immediately pick it out and correct it.

HTH

[mattkw80]

Alright, thanks for the info.

The Kick mic did pick up a little bit of other stuff, but your right I could probably gate that out if I really needed to, because it's not really hitting at the same time as anything else.

I did not try the additional Snare mic and kick mic on the first setup (recorder man setup) as we ran out of time, and as well, I didn't think about it until after. I'm going to try it tommorow.

The recorder man method + ability to add in more snare and/or kick will hopefully work out well. I guess I'll just have to factor in the 3 to 1 rule when positioning the snare mic, and the 2 "recorder man" mics.

I had another idea - I think I'm going to purposely record some things WITH phase problems, so I will be used to hearing it.

What would be a good way to mic something "the wrong way" so I can get a really good idea as to what bad phase sounds like ?

[DAS19]

Ive come to realize phase can always be taking care of later usually. The recoderman technqiue is already in phase. They actually make a phase thing that you can find hte exact degree of phase that puts the tracks in phase or something like that.

Theres a lot of tricks and just knowing the concept of phase really well will help you. I use the recorderman technique as well but I add the bass drum and snare mics like you said you want to. Phase didnt really matter all that much all you have to do is move back the two snare and drum tracks to start exactly with the overheads. Usually this will give you back your phase relationship.

Oh yeah and using two snare mics you always need to flip the phase.

Hope I helped.

[DAS19]

You cant really tell if somethings outta phase unless youve heard stuff thats out of phase and then in phase. Theres just a lot of bass frequencies you lose and other minor stuff. IT doenst even sound all that drastic but it makes a big difference when your looking for that punch. I wa slike you when I started and worried about phase but its really nothing to worry about becuase it can all be handled in the mixing process 9 times outta 10.

[DAS19]

3 to 1 rule on the snare and kick mics? just throw the mic on them man.

[mattkw80]

Thanks DAS19.

I'm going to throw the Snare and Kick Mics on the recorder man technique today - I'm pretty excited, because I did get the best results I ever had on a drum kit, with that technique, so seperated snare and kick should be the icing on the cake.

What kinds of things do you do to fix the phase problems later?

[NL5]

One thing to consider when thinking of phase - the ROOM. You will get all kinds of phase issues even with ONE MIC due to the room. Let's hear more about the room, and where the kit was located within the room.

[mixsit]

Originally Posted by mattkw80

...The recorder man method + ability to add in more snare and/or kick will hopefully work out well. I guess I'll just have to factor in the 3 to 1 rule when positioning the snare mic, and the 2 "recorder man" mics.

Forget 3:1 in this context. That's not what it's for. (Notice how 'recorder man setup breaks the rule. Besides, at 2-4" vs 2-4' you're already...

First, the polarity switch.
Check this out. The O/H's are pointing down. The top snare mic is likely pointing damned near 90 degrees from the side. The choices are 0' and '180.

Distance difference (time- not a 'ratio') is phase tone'.
Except for the long waves (at these distances) all midrange and up tones are in/out of phase combinations. (See bennychico11 above.

I had another idea - I think I'm going to purposely record some things WITH phase problems, so I will be used to hearing it.

Play with the relative distances, flip polarity.

Good tone, 'good phase'. Bad tone, 'bad phase'.

[mixsit]

Originally Posted by mattkw80

What kinds of things do you do to fix the phase problems later?

Shift relative time.

[SouthSIDE Glen]

Originally Posted by mattkw80

What kinds of things do you do to fix the phase problems later?

Reduce the gain or mute entirely all those purely optional mic tracks. The more mics, the more phase issues.

Let the OHs pull the majority of the weight, and use all the extra crap for light seasoning only.

G.

[mattkw80]

I will draw a diagram of the room.

I wouldn't mind somebody taking a look at what I've got going on there, and what I have done with the corner's.

I'll put a web page together with a diagram and some photo's.

Thanks for your help so far guys.

[mattkw80]

Alright...... here's the photo's and layout of my studio.

http://www.effortlessrecords.com/studio.htm


I'm also going to have this posted on a proper thread, asking for suggestions about the layout and acoustics of my space.

Thank you for taking a look, and any suggestions you may have.

[NL5]

I'd get the drums out of the corner and away from the wall as much as possible......

[DAS19]

Originally Posted by NL5

One thing to consider when thinking of phase - the ROOM. You will get all kinds of phase issues even with ONE MIC due to the room. Let's hear more about the room, and where the kit was located within the room.

Its a good point I forgot about. A square room will cause standing waves giving you more phase cancellation.

[NL5]

Originally Posted by DAS19

Its a good point I forgot about. A square room will cause standing waves giving you more phase cancellation.

Any room with parrallel surfaces will give you standing wave. There's also comb filtering.

[mattkw80]

I don't really have that many parallel surfaces..... just the wall at "north" and "south" and I do have the diffusers in the corners.

The "west" and "east" walls don't really match up parallel, as I have the hallways at the side.

[NL5]

Originally Posted by mattkw80

I don't really have that many parallel surfaces..... just the wall at "north" and "south" and I do have the diffusers in the corners.

The "west" and "east" walls don't really match up parallel, as I have the hallways at the side.

Your walls, and ceiling are splayed? The looked to be parallel in your drawing. Sorry, my bad.

Still, you should get the kit as far away from reflective surfaces as possible.

[mattkw80]

Not sure what you mean by splayed NL5.....

The main room is a rectangle, but the 'west' side goes into another horizontal rectangle.


The North and South Walls are parallell, but they are also 24' apart.

[NL5]

Originally Posted by mattkw80

Not sure what you mean by splayed NL5.....

The main room is a rectangle, but the 'west' side goes into another horizontal rectangle.


The North and South Walls are parallell, but they are also 24' apart.

Splayed means that they don't run parallel. From the sounds of it, all your surfaces are parallel (the normal way houses are constructed). That's what your drawing shows too. Here is a link to a crude drawing of my CR - I put up splayed walls -

http://homerecording.com/bbs/showpos...25&postcount=1

Having a big room sure does help though - all the more reason to get the drumkit away from the wall.

[mattkw80]

Would you consider the room I am working in big ?

I see what you mean from your floor plan.... did you ever end up completing that project?

[jrhager84]

I'd listen to NL5, he knows what's up....

[IronFlippy]

Or you can phase align later, manually. Look at the problem tracks and you'll see that as one's voltage increases (the waveform goes up from 0), it won't match the other. Just slide one of them over so that it matches up at the start of the waveform and you'll be in better phase than you were before. Of course, the entire waveform won't be perfectly in phase, but the beginning is the attack. If the attack is in phase, it should sound "punchier" or "tighter". If you need, I can get pics up for you in the morning to show you what I mean.

[mattkw80]

Does anybody here use Elemental Audio InspectorXL to visually look for phase problems ?

[giraffe]

once in a while, you can purposefully have 2 different mics on something, purposefully out of phase.

one is your "main source" (per say) and the other you mix in just the amount you want to get the desired change in sound.
not something you'll use every day, but it can be good.