Phase of overheads

[thefridge]

Greetings all, on checking the phase of the X/Y configured drum overheads, positioned about 60cm directly above the drummers head, (SM58's,not ideal), there was a huge difference in "position" of one of the OH when out of phase- even when all the other drum mics where sounding in correct phase. The sound seemed to migrate to behind my head, giving a sort of surround type effect. I thought it sounded cool, in a way, as I was trying to widen the stereo field, so I put a phase scope on the drum group to see what it said, sure enough,wider stereo when one OH out of phase, but when all the tracks are up, and the phase scope is last on the master bus, there is no noticable difference on the phasescope, and I am not sure if I can hear any difference in the full mix when a/b the phase of 1 OH.
So, not wanting to "mix with my eyes", I have 2 questions, 1, will this comb filtering?? effect (if it is that) store up unexpected nasties for me later in the mix if I keep it? and 2, how wide should the plot on the phasescope be for drum group, and master bus. At the moment, with both OH in phase, the drums are very mono, ie vertical plot, even with max panning, and its not so different on the master. Many thanks, Mick

[Mark Bassett]

My first reply would be that if it sounds right, it is right.

I'm sure someone like Rick will have insight into the finer points of the gioniometer, but as far as the X/Y stereo technique goes, generally the closer your mics are together, the less width you are going to get. Try a spaced pair AB technique, this will yield a better 'width' to the soundstage, and certainly will look wider on your gioniometer. Depending on the positioning of the capsules, coincident techniques generally rely on amplitude differences at the capsules for localisation, whereas a spaced pair relies on arrival time (phase) differences for localisation. Spaced pairs sound much wider.

Also, have you reversed the panning for your XY technique? Make sure the mic pointing at the floor tom (for example) correlates with your floor tom panning. You could certainly get less width by not reversing the panning on your overheads. What do the drums sound like just through the overheads?

[thefridge]

Haa! The panning was wrong as you suggested, ie the (close XY) left OH,the one on the left as you face the kit, I had panned hard left, but of course it was actually looking towards the right, so I just tried panning them the other way- bingo! Wider stereo, more bottom end, subtle but definate. I wont forget that in a hurry!
The whole kit sounds pretty good just on the OH's, no real kick to speak of , but the snare has more of the sound I am after- more wood- than the close 57. Thanks very much for the advice, and quick reply!!! cheers!