Phase reversal on mics

Phase correction is its own branch of recording technology. There are tools for performing phase correction in the digital domain, and in the analog domain. I've heard of folks literally dragging one track into phase with another in a DAW, but have never done it myself.

Phase is only a major problem when two mics are hearing the same thing at similar levels at different times. Close micing the kit solves this problem to a great degree. There will be some bleed, but not enough to wash out the main mic. You can also gate the mics so that the bleed doesn't poke through as much.

In general less mics = less phase issues. I often use a 3-mic technique and it gets better results because it has less potential phase issues. Depending on the style you can get great results with one overhead on the kit. It helps to have the right mic for that

Not knowing how big the kit is, the style, the expected results, and what mics you have makes it impossible to be specific about a solution. But regardless of what you do it ends up with the engineer using their ears.

 

This is why recording drums can be really hard. Phase can definately be an issue when micing drums. Generally I take the time to make sure that the overheads, kick and snare are in best phase as I can get them. Then throw on your tome and hat mic, plus whatever. As stated before, the fewer the mics the fewer instances where phase can kill the tone. However it is difficult to get some drum sounds with only three or four mics. This dirrectly relates to how good a room you have to record. IMHO the deader the better. The cleaner and tighter the drum recording, the more freedom you have in the mix. When the drums sound like they were clearly recorded in a garage, well they are never going to sound like they were not recorded in a garage. This often leads to over micing the set, on top of poor acoustics and so phase, phase, phase. If possible I will mic the crap out of the kit, but only use what I need in the mix. This may include room mics and various mics around the kit. It is ultimatley decided by the type of music and what fits the song.

So back to phase. If this recording is important, hire a good engineer. Use as best a facility as you can afford. You as the musician should not be concerned with phase. In fact if you are bugging the engineer about phase you are wasting his time and your money. If he is good, you won't have a problem.

I have time aligned tracks in Pro Tools, if you are carefull it can actually be quite useful. For one reason or another some times stuff gets tracked out of phase. If the guitar cab has multiple mics, lineing them up, or even messing with the alignment can bring out the tone, or make is sound like ass, just gotta use your ears. I have also messed with the alignment of the room mic, results varying of course.

 

The drum overheads should usually be as close together as possible. This will eliminate most phase issues. I do this with small-diaphragm condensors in the X/Y configuration.

There are overhead methods involving spaced pairs (I think Glynis Johns has one) in which both mics must be equidistant from the snare drum. They would also need some sort of precise measurement between them.

If you use a room mic, be sure it's far enough away.

 

Not necessarily. I am not that much of a fan of X/Y it works in a pinch but the stereo image is lacking for me. But yes it does eleminate phase issues between the OH's. Though using ORTF or a properly placed spaced pair, you won't have problems either. Just takes a little more time to setup.

How far is far enough away? 10' 15' 50'? I say put it where it sounds good. I have had good results with an omni at head level 8 directly in front of the kit. Also stuck a figure 8 bout 10 or 12 feet in air in the far corner of the room. Becareful throwing around should's and should nots, there are no rules for mic placement. If it sounds good it is good.

 

To find problems: solo each mic, does it sound full and how you like it? Good, does it sound washed out and not full when you turn all of the mics on? Bad, solo more mics one at a time with that mic, find out what is cancelling the original mic.

The snare sounds good for me miced top and bottom, reverse the phase on the bottom.
The kick drum phase is a very old debate, some argue the mic is in the reverse of all other mics (inside the drum, while the toms and snare mics are on the top) so they say flip it 180. Some argue the kick is being recorded as it would be heard, straight at the audience. I leave it that way.
Over head phasing depends on the height of the ceiling above the kit, 8' in a regular house and you will have issues no matter X/Y or opposite sides of the kit.