Today we have a question from loyal Sweetwater Sound customer, Bryan H. He asks: “I understand the basic principles of phase shift effect caused by varying distance of two microphones recording one source. This is typically an undesired effect. How do you avoid (or deal with) phase shift effects from overhead room mics (say, for a drum kit) used in combination with close mics on individual instruments. I read that overhead mics are important for capturing sonic qualities of the room, but don’t they also increase phase problems?”
Yes they do. However phase problems aren’t always bad. Your brain uses phase relationships (among other things) to locate sounds in three-dimensional space all the time. To some extent the phase relationship between overheads and direct drum mics works in your favor to open up the kit and make it sound larger than life. On the other hand they can just as easily render a track inarticulate and weak sounding. Being able to properly record a drum set is still one of the great undefined arts of recording. It’s not easy and it’s never going to be easy (at least not in our lifetime). There are too many variables, and what we think of as a good drum sound is a moving target anyway (Don’t believe this? Listen to any pop recording from 1988). Given that phase “problems” are a fact of life when dealing with multiple microphones as on a drum kit the skill is in learning how to use them to your advantage while minimizing their negative side effects. Attempting to document this art is not only well beyond the scope of inSync, but also dismisses what a complex deep skill it is. There are many good books on the subject and it is a skill that can be learned. As an aside, one interesting way around the delay between the close miked drums and the overheads is to put the drum tracks into a DAW and move the overhead tracks forward in time by a few milliseconds. The same effect can also be achieved by using the track delay feature of most of the MDM machines. This is worth trying as it produces a very different sonic feel that is sometimes very effective.