Want to bring some life to your recordings? Put stereo miking to work! A number of companies manufacture stereo microphones — that is, they’ve placed two microphone capsules within a single body. Then there are companies who supply stereo pairs of mics — or you can use a pair of identical mics to create a stereo rig. With a stereo microphone setup, you capture the depth and spatial presence of an instrument or ensemble in a very convenient manner. Whether you choose a single-unit stereo mic or a pair of microphones, stereo miking is well worth exploring! (Check out my list of six great stereo mics at the end of this article.)
There are many ways to set up a stereo mic rig. Virtually all single-unit stereo microphones can be used in an X-Y pattern, some stereo microphones offer more flexibility; they can be used in a Blumlein configuration or or even in a Mid-Side configuration. When you combine a pair of separate mics for stereo, you’re even freer to choose the configuration you want to use. Here are three stereo mic configurations you might commonly use:
The X-Y pattern is fairly straightforward; two cardioid microphone capsules are placed “coincident” — so that the center of the capsules are in the same plane — with the capsules aimed at a 90-degree angle relative to one another. (Various other coincident stereo miking techniques use other angles between the capsules; feel free to experiment.)
The Blumlein technique uses a pair of figure-8 pattern microphones rather than the cardioid pattern that is used in the typical X-Y configuration, though the two mics are still set up in a coincident 90-degree X-Y arrangement. The figure-8 pattern means that the microphones are also picking up sounds from the back of the microphone. These are typically room reflections and ambience that will add a sense of space to the recorded track.
The M-S technique uses one microphone with a cardioid pattern facing forward toward the sound source and a second microphone with a figure-8 pattern placed at a 90-degree angle to the cardioid pattern (facing left/right).The best part of the Mid-Side (M-S) pattern is its mono compatibility. The M-S recording requires some set up to decode, but the payoff is 100% mono compatibility and continuous control over the “stereo-ness” of the signal. (Learn more about the Mid-Side stereo microphone technique here.)
Try it Out!
Here are six ways that stereo miking can be used to improve your recordings. (The use of a stereo miking to record entire ensembles is beyond the scope of this article; that will be covered at another time.)
1 – Individual Instruments
While a single microphone works well when recording acoustic instruments, close-miking in stereo will give you a more natural acoustic representation the way a listener is accustomed to hearing than a mono track will, and offers more options to play with at mixing time. With the stereo microphone 6-12 inches from the instrument, the recorded track will have the immediacy and intimacy you’re used to hearing from close-miked instruments, yet will help to fill the stereo field in an interesting way.
In general, the X-Y pattern works best for this sort of thing, because with X-Y you have more panning options in the mix. Even though “stereo” implies hard panning, it’s not required when working with stereo tracks of individual instruments. Instead of panning a stereo guitar track hard left and hard right, try panning one of the tracks to the middle. This places the guitar image more to one side of the stereo field while allowing it a bit more width than a mono microphone would allow. If the recording has two acoustic guitars overdubbed, try panning one stereo-miked guitar hard left and center and the other hard right and center. This can yield lovely results.
2 – Close-miked Piano
The sound of a piano miked from inside the instrument, just above the soundboard, has become a standard approach for contemporary popular music; it gives the perception of great clarity and detail. If that’s the sound you need, stereo mics in an X-Y pattern, placed about a foot behind the hammers and approximately six inches above the strings will capture it admirably. The X-Y microphone pattern will give a sense of stereo width, with the piano’s low notes a bit more prominent on one side and the high notes a bit more prominent on the other.
3 – Outside the Piano
While the close-miked piano sound has become common in the recording studio, it doesn’t capture all of the complexity of the instrument. To get closer to what a piano sounds like from the perspective of an audience, the microphones must be moved outside the piano. For non-classical (yet fairly natural) piano, a stereo mic setup with an X-Y or Blumlein pattern can be placed approximately two feet from the curve of the piano and about nine inches above the lip. This mic placement allows for a bit of the sound of the room around the piano without losing all of the detail that comes from inside miking.
4 – Drum Overheads
Though a spaced pair of mics is probably the most common way to record the overheads on a drum set, in a normal drum room, stereo mics in an X-Y pattern can work even better; the stereo mics will have fewer phasing issues than a spaced pair, and it will only require one microphone stand.
If you should happen to be recording drums in a great-sounding room (and you have a stereo mics with figure-8 patterns), consider using a Blumlein configuration. Remember that Blumlein uses two figure-8 capsules, so it captures the sound of the room along with the direct source — but consider the height and acoustic reflectiveness of the ceiling behind the mics because whatever bounces off the ceiling above the drum set will affect the recording. If the ceiling is low and acoustically hard (reflective), you may end up with problematic reflections.
5 – Ambient Drum Miking
In addition to the standard drum miking setup, consider placing stereo mics out in front of the drum set. The actual distance depends on the size of the room of course, but if you have six feet of room in front of the drums (or as much as 15 feet), stereo mics in this position can add welcome ambience to the drum sound without smearing the image too much. The quality of the acoustic space will determine which microphone configuration will be best suited to this (experiment with the options), but the Mid-Side technique could be very interesting here, as would the Blumlein configuration, which would emphasize more of the room sound.
If you’d like more ambience than simply putting stereo mics a few feet from the drums, try putting the stereo microphones as far as possible from the drum set, and point the capsules away from the drums. Try the back wall of the room, or even point the microphones at the ceiling. The goal of this mic placement is to minimize the direct sound of the drums while emphasizing the reflections from the room. Many engineers will take these ambient tracks and run them through a limiter set to “stun” — the classic technique is using an 1176 with all of its buttons pushed in — to bring out the ambient sounds even more. Tuck the resulting stereo track up under the drum mix for ambience or turn it up louder for a gnarly crunch.
6 – Horn recording
When tracking a horn section, put stereo mics near the opposite wall from the horn players. Even when close-miking each of the horns, the mics at the end of the room will add nice ambience. If you need to double-track or triple-track horn parts (so that a four-horn section becomes an eight- or 12-horn section), remember to record another stereo ambience track for each double. If the horns also play solos, record yet another stereo ambience track along with the close mic. Judicious use of these stereo tracks will help to glue the various horn passes together, strengthening the impression of a group of musicians playing (and even soloing) live.
But why stop there? There are tons more ways you can use stereo microphones; put your imagination to work. In fact, try out stereo mics anywhere you would normally use a single “mono” mic — you may get great results! (Stereo miked vocals, anyone?)
Stereo microphones can be an excellent addition to your mic locker; experimenting with them will yield new and novel ways to add space, depth, and dimension to your recordings.
6 Great Stereo Mics
For this list, I’m going to include both single-unit stereo mics that contain dual capsules as well as pairs of mics that can be used for stereo. It’s easy enough to set up two mics on a stereo mic bar to create a stereo mic!
1. Behringer C2m
The Behringer C2m mic pair is a super-affordable way to give stereo mics a try!
2. Rode NT4
I’ve used the Rode NT4 single-unit stereo mic for tons of tracks, on all sorts of sources.
3. AKG C414
Stereo mics don’t have to be small-diaphragms! A pair of the ubiquitous AKG C414 mics offers an awesome stereo result on just about any source.
4. Royer SF12
Two of Royer’s highly detailed and dynamic SF1 mics in a single unit? Yes, please! The SF12 is perfect for ensembles, room ambience, acoustic instruments, and much more.
5. Shure MV88
Want to record stereo into an iPad or iPhone? The tiny and affordable Shure MV88 plugs right in, and it sounds great!
6. AEA R88
Combining two of AEA’s Big Ribbon R84 mics into one unit, the R88 is my all-time favorite stereo drum overhead mic.