0% Interest for 24 Months! Learn more »
(800) 222-4700
  • Español: (800) 222-4701
Spring Clearance

Sweetwater Forums [Archived]

After 15 years of great discussions, the Sweetwater Forums are now closed and preserved as a "read-only" resource. For discussions about current gear, check us out on Facebook, YouTube, inSync, and our Knowledge Base.

Phase issues


Hey, I'm recording guitar at the moment and I want to use two mics on the amp. I am using a SM57 and an AKG C4000B. I've been having troubles getting a sound that is it phase however. I've tried moving one mic in relation to the other with varied success and I've also tried flipping the phase in Pro tools. I was wondering if anyone had any suggestions for solutions when multi-miking an amplified source. How much attention should be paid to reflections if it's close miked? Thanks to anyone that can give some help.
July 28, 2003 @07:46pm

How are the mics placed in relation to eachother and the amp cabinet? If you have on in front of the grill facing the cone of the speaker, and one at the back of the cabinet so the mics are facing eachother, this is where you would have the biggest phase issues. If you are using one at the grill of the amp, and one at a distance for ambience, then you will have to fiddle with it to find a good place to position the distant mic. If you have a lot of reflections in the room (almost completely unavoidable) comb filtering (phase problems) will (more often than not) result when using a distant mic when combined with a close mic. If you just close mic, reflections are not a problem.
July 28, 2003 @11:43pm

The simplest way of avoiding it is to place the mics at the same distance from the cone. If you use one of the mics to pick up ambient sound (C4000B in omni?) the phase filtering is naturally reduced by the fact you use way smaller amount of the ambient mic in the mix. If you want to mix them about half/half you'll have to wiggle around with it until you find a spot you like, but there's no getting rid of the phasing itself. You can also pan one mic to the left and the other to the right, that helps too.
BTW: I usually engage the 100Hz hi-pass on my C4000B when close micing my guitar cab. (just for your consideration)
ALSO TO NOTE: When I mike my combo both from front and rear I sometimes leave both signals in their original form (uninverted). It really depends of what sound you're looking for.
July 29, 2003 @09:17am