An omnidirectional microphone “hears” sound from every direction, so it wouldn’t seem like the best choice for capturing clear, clean, and isolated vocals in the studio, and only a lunatic would sing through one onstage amidst blaring amps, drums, and monitors. But this doesn’t mean that omnis should be avoided as if they just caught very bad cases of H1N1. These mics—or, more accurately, these polar patterns—offer some very attractive characteristics to vocalists of all genders, styles, and dynamic levels.
Many musicians are introduced to the omni pattern via multi-pattern, largediaphragm condenser mics such as the AKG C414 (omni, figure-8, hypercardioid, cardioid, wide cardioid), Shure KSM44 (omni, cardioid, figure- 8), and Audio-Technica AT4050 (omni, cardioid, figure-8). Those who never move the pattern switch off “cardioid” are missing a fair amount of aural treats. Sure, the heart-shaped cardioid pattern may appear to be more of a “useable” option for recording vocals as it mostly picks up sound from the front, and rejects much of the sound occurring at its rear and sides. But while cardioid patterns minimize ambient noise and focus on what’s coming out of the singer’s mouth, they also exhibit offaxis coloration (where the tone of the voice changes as the singer moves away from the front of the mic) and proximity effect (where low frequencies are intensified as the singer’s mouth gets closer to the mic), and are susceptible to plosives (those annoying popping “p” sounds).
Meanwhile, the omni pattern is often considered the purest-sounding polar pattern because it adds very little coloration to the original sound. Omnis are also less sensitive to plosives, and, by virtue of the fact they capture sound equally from all directions, off-axis coloration is negligible. So if you desire a relatively pristine, accurate, and balanced vocal track— along with the bonus of some natural ambience that might make reverb unnecessary at the mixdown—the omni starts looking like an option of true genius. Here, then, are a couple of tips to maximize the pattern’s benefits, while minimizing its potential shortcomings.
Circle of Sound
As stated earlier, omnis capture sound from all directions, so you have to be very conscious of your recording environment in order to achieve optimum results. However, I view the 360-degree audio field as a benefit. As long as your housemates aren’t cranking up the big-screen TV’s surround sound, environmental noises shouldn’t be too much of a problem, and gaining some ambience is a nice aural homage to the days when vocals were sometimes cut in big studio spaces. Look for a spot in your home that offers the most pleasant ambience. Do some test recordings, and listen to how the environment affects the tone and vibe of the vocal. Take care not to go too crazy, as you can’t remove the reverberation once you record it down with the vocal, so what you get is what you’ll have always and forever. Too much ambience, for example, could sound unnatural in a mix where the other instruments are rather dry. I like to hear a clear, dry-ish vocal with a hint of air and decay, so my favorite “vocal booth” is my home office, where a hardwood floor is about 40-percent covered by a rug.
Working an omni mic is a pretty organic experience, because you don’t get that annoying proximity effect, and breath pops (wind) are minimal. I start about one foot from the mic to get a good blend of room and vocal, and then move in a bit for softer phrases. If you’ve chosen the right space to record in, cutting vocals can be that easy. I dig visualizing Frank Sinatra singing freely in the big room at Capitol Studios and just work the mic. Of course, I don’t sound anything like Frank—sadly—but bringing some Rat Pack vibe into a vocal session helps my performance. Your experience will likely be different, but most singers feel pretty good about being able to move around a bit and achieve good results, rather than sticking close to a pop screen when using a cardioid pattern.