Audio Recording Issues – Multiple Microphones Setup to Track the Same Instrument and Need the Right Balancing Together Part TwoBalancing the drums is about the volume levels in comparison to the mix, but it is also about balancing the top and bottom head microphones of each drum if using both. You may have more of certain drums captured in overheads and room mics than the others.
Once you are mixing and blending things together, you may find a more intricate process developing. Let's say that the direct mic blend for the snare is perfect when it reaches a certain volume, but it tends to have too much of a certain Frequency when you feed the overheads into the mix. Or, the complex stereo capture of the overheads are great for the whole set in the context of the mix, but they lean too heavy on certain Frequencies. The Equalization decisions may be very tricky. Each drum and each mic choice may have areas that take away from other instruments. Before you go carving away chunks of great tones, consider creating an order of preferences and levels of importance. You may find that some Frequencies are best to reduce from a track other than the drum or overheads, and in other situations you may find that some Frequencies appear to stand out because of positioning or even due to timing. Often, the small delays that build up from the distance of one mic to the next can create a Frequency that results from this distance between the two. It isn't always necessarily phase, as we usually call it. Sometimes, it is more about what I call the reach of the microphone more than the timing element.
Let's pretend that I set up two of the exact same mic to record a single drum sound. Both mics are in an omni mode. The first mic is placed one foot away from the drum and the second is ten feet back from mic number one, eleven feet from the drum. Once recorded, there is not only the difference in the sound of the instrument, but its effect on the walls around and the ceiling above and floor beneath. With both mics in omni mode, they are both picking up a lot of information from their surroundings. The sound is going to travel a distance before it reaches the second mic, but also in that time, the first mic has resounded across the room, so there is an initial attack from the drum, no doubt captured with more intensity and clarity by the first mic, and the wash over, or reflections of the room, whether small, short, tight or big, long and open. That second mic will hear a residual attack very shortly after, with a different resonance and a larger blend of the room, along with the resulting room sound that the hit creates and the blend of the room from a distance. We could align these two responses in time so that the later recording is brought forward to play at the same time as the closest mic, but this is not always the best decision.
Sometimes, the mic choices lead to a phase correlation issue that is best resolved by aligning the timing of mics. Other times, it is the distance itself that we want to measure in the sound. Still other times, the range of Frequencies can be complicated by the reach of the mic, meaning that the sound waves that develop in that distance are being captured by the distant mic and not just the alignment of the time, meaning that any change in distance and position can affect Frequencies that otherwise would not exist in reality. They are a combination of the sound created, the room reaction, but also an equation of the sound captured by mic one added to the sound captured by mic two, the result being additive and sometimes the results can cancel out some Frequencies and boost others, all the while responding largely accurate to the source and distance. In this case, we can adjust timing, which can have a negative affect on the timing between other instruments or drums, or we can reduce the residual bumps in the recording from one mic or the other, or a little bit of both.