The polarity reversing soft knob on the DA7 is very helpful in most cases. I am curious to learn from you folks what other methods you incorporate for controlling phase problems. Specifically, the use of delay, mic placement technique, or any other electronic doodads which have found there way into your studios.

If you use a DAW you can move the tracks in phase. It's easy to see the tracks out of alignment. I know alot of engs who physicallly move the room mic tracks on the drum kit where they want them to be. It's also a great way to create ambience w/out reverbs. If you use Adats or DA's you can delay the tracks either with the console delay fucntion (which is way easier)or the MDM's delay functions. I usually start with mic placements. A little common sense goes a long way. Then I deal with flipping mics that I might have phase issues with. Flip and listen. I may not even add room mics to the soup. I might listen to them and record them but not bring them in the mix when I'm recording. I'll deal with them later. Don't think I would do that recording to a 2" machine but with a DAW it's easy. A simple rule to follow, the more mics you add to the mix, the more chances you'll have phase issues. Silk.

I agree with silk. Phase cancellation is a tremendous problem that could be fixed instantaneously. It's very easy to identify by ear. You just have to test if it's there or not. One way to avoid phase cancelation is to use the 3:1 principle that states for every unit of distance between each mic and it's source, the distance between mics should be at least 3 times that mic-to-source distance. Another reason you'd get phase cancellation is to make sure your mic cables are electrically in phase with eachother. The proper polarity of an XLR connector pin2(+), pin 3(-). It's always good to identify the problem before you have to find a solution for it.

You can use phase cancellation to your benefit as well. But, as with anything, your ears are the final judge.

Phase cancellation happens all the time. It's an important part of the reality we perceive. As you sit in front of your computer, typing, the sound of the keyboard isn't a pure and direct sound. There is reverb, separation, distance, intensity, not to mention - other sounds that cause cancellation. However, it's being true to reality so you can't hear the cancellation. It sounds normal.

The idea behind using phase cancellation to your advantage is to keep the cancellation subtle. If there is a mic placed on a source, know that another mic 10' behind it will sound like reverb. And yes, there will be some amount of cancellation. Keep the relationship of volume close to what's natural (how much reverb comes from a wall?) and the cancellation will sound natural. Does music sound good standing next to a wall? Normally, no. So, keep your more distant mics lower in volume. Again, there will be some cancellation, but that's OK. It's part of what reality is about.

Phasing is only an issue when you change the relationship between sources using time. This can be the time it takes sound to travel or an electronically delayed signal. You don't necessarily have to "fix" the phase with every change, but with every change - know that you're effectively changing the acoustics of the room (or mic). If you want a tight sounding room, keep everything as close to in phase as you can, you want more distance you can be sloppier with the phase... but again, mics providing a reverb type ambiance should be lower in volume in the mix than the closer mics.

Just keep the relationship natural - and it will sound fine. Change that relationship and you WILL have to fix it (somehow). I'm not saying that you can't augment reality... just that the end product should represent some sort of natural reality.

Maybe this is way too obvious--but checking things in mono with reveal phasing problems. If it sounds there in mono, it will probably be okay in the mix.

I have my Finalizer Plus hooked up to the XLR digital out of the DA7. It has a phase relationship utility. I can send out a 2 channel mix and see if theres a phase problem. Some times keyboards can be slightly out, by panning L 11- R 11 it can bring it back more in phase instead of having them hard right , hard left. Also delaying a snare mic by 1 or 2 mil can bring it out more while mixed in with the over heads.
I don't double mic acoustic guitars anymore because of phase problems and low mid buildup. 1 mic with a good verb does the trick for me.