We’re going to discuss two different techniques for miking a piano: one using a simpler setup, with a pair of very affordable mics, and another more advanced setup using more expensive mics.
Our first setup uses only two mics, a matched pair of Cascade Fat Head II ribbon microphones. As is typical for ribbon mics, these two have a figure-eight, or bidirectional, pickup pattern. Given that fact, we decided to set these two up in a Blumlein configuration to capture a stereo recording of the piano. The Blumlein technique is similar to X-Y technique, except that it uses two figure-8 mics instead of two cardioid mics. You need to hang one of the mics over the other so that the capsules are at 90 degrees relative to each other, and the capsules are as close as possible to being in the same space. With two figure-8 capsules at 90 degrees to each other, the front and rear pickup zones of the two mics together cover a good deal of the 360 degrees around the two mics, allowing us to hear a good, phase-coherent stereo recording of both the piano and the room.You can vary the distance between the mics and the piano to control how much room sound is on the recording. A good starting place is about 2 ½ – 3 ft away from the piano’s soundboard, aimed at its center. For a roomier sound, move the mics farther away from the soundboard.
Our second setup is a little more involved. We used two different stereo configurations, with two more expensive sets of mics: a pair of Soundeluxe U95Ss and a pair of Neumann KMi84s. The Soundeluxes were spaced 3-4 feet apart in an A-B stereo configuration, angled slightly down toward the soundboard and about 6 inches to 1 foot away. This configuration offers a very wide, exciting stereo recording of the piano, with not much room tone. The Neumanns were arranged on a stereo bar into the X-Y configuration, and placed about 3 or 4 feet back from the Soundeluxes, capturing much more of the sound of the room. The X-Y array had to be moved somewhat farther back from where it was originally placed to achieve maximum phase coherence with the pair of Soundeluxes. We moved it back to about 3 or 4 feet from the soundboard to comply with the 3:1 rule, a principle which states that when using multiple mics to capture one source, the second mic should be at least 3 times as far from the source as the first. After moving the X-Y pair back, the sound of the piano in the room was much fuller and vastly improved.
As you can see, there are many different ways you can approach recording a piano, depending on the type of sound you are trying to capture. We were able to capture 2 unique piano sounds using our 2 separate miking techniques, both of which sounded wonderful in their own right. The main thing you want to keep in mind is taking the time to properly place your microphones makes all the difference in the quality of sound you will obtain.