How to choose a Studio Microphone
Why do I need a studio microphone?
Quite simply, to record any ‘real’ sounds like vocals, guitars, amps, pianos, strings, brass or a multitude of other things that might end up in your productions. To achieve a good sound quality, a built-in mic or a phone mic just won’t cut it, unless you are deliberately going for a lo-fi effect. The good news is that studio microphones are less expensive than you may have thought, and by choosing one that’s right for you, it’s possible to cover different kinds of recording tasks without having to buy lots of different models. So what are the different kinds of mics, and what are they good at?
Types of studio microphones
Condenser mics (also sometimes known as capacitor mics) consist of a thin diaphragm inside a mesh casing that acts as a capacitor. They require phantom power, which either comes from your audio interface, a mixing desk or a dedicated power supply unit. Dynamic microphones generate audio signal through the movement of a conductor within a magnetic field. They don’t require phantom power and tend to be much more robust and better able to handle high sound pressure levels than other kinds of microphone. This means they lack a little of the detail you might want for studio recording, but can be great for live use or recording really loud sources. Ribbon mics work by suspending a small metal element in a magnetic field and responding to the velocity of the air molecules passing it. The most recent development in the mic world has been USB mics, and these are increasingly popular. They are much like regular condenser mics except that they also have a built-in preamp and an analogue-to-digital converter. These two additional elements mean you can connect it directly to a computer’s USB port for recording, and there’s often a headphone jack built-in for monitoring.
What are polar patterns?
These define the way that pickups are arranged inside a mic, and affect the way they detect sound. Different polar patterns are suited to different applications.
Cardioid is one of the most common polar patterns and essentially means sensitivity to sound from in front of the mic, good sensitivity to the sides but none from the rear. This makes them very popular for many recording tasks, since they offer good isolation of the sound source. If you get very close to a cardioid mic, it can exhibit the proximity effect, something worth bearing in mind. Some mics include a built-in bass roll-of switch to compensate for the exaggerated low frequencies that can result from the proximity effect. Super and Hypercardioid mics are similar, but even more directional. These are popular when a very high degree of isolation is needed, such as mic’ing up a drum kit.
Omnidirectional mics pick up sound from literally all around and are not focused in any one direction. These are less useful for some tasks, but can be helpful when you are trying to capture not only a sound source but the ambience of the room around it. A guitar playing in a church, for example, or a choir in the same environment.
Which studio mic to choose?
Vocals are almost always recorded with a large diaphragm condenser mic, and a cardioid pattern is usually favoured because it helps to avoid colouration of the sound by the room. If you have a really good recording room or specifically want to capture the sound of the space you’re in, you could try an omnidirectional mic. Vocals should always be recorded with a popshield to prevent plosives, and in certain cases you could even try a dynamic mic because it will give you a more rough-edged, ‘rocky’ sound.
Electric guitars can be recorded with a variety of mics, and providing they are of good quality, the positioning is often more important than the models used. You’ll need one that can deal with a high sound pressure level if you’re going to be sticking it in front of a noisy amp, and one with a good bass response for recording bass amps. It’s not uncommon to use a dynamic mic such as a Shure SM57 to record guitars, or a stereo pair, or one close up on the amp and one further away.
Acoustic guitars often perform best when recorded using small diaphragm condenser mics, and again, correct placement is essential to getting a good sound. Cardioid polar patterns usually result in a more focused sound, though as with vocals, omni pattern mics can sound good if you’re recording in a great-sounding physical space.
Drums require several kinds of mic. Kick drum mics need a high sound-pressure handling ability as well as a good low-end response, of course. A dedicated kick drum mic is usually a good idea. Close mic’ing individual drums needs a dynamic, cardioid style of mic. It’s a good idea to use dedicated drum mics for this, as the physical requirements of clipping them to toms and pointing them at snares means that large mics might be problematic. For room and overhead mics, many engineers use small diaphragm condenser mics. Again, placement is key.
There are a lot of mics around and the choice can be confusing. Reviews are actually a decent place to start if you’re unsure, because they can help to cut through some of the jargon. A large diaphragm condenser mic is a pretty safe bet to be a good all round performer, adept at everything from vocals to acoustic guitars and even guitar and bass amps. Bear in mind that it will probably need to be phantom powered, so you will need this facility on your audio interface or mixing desk. A smaller diaphragm mic or a dynamic mic would be good if you plan on doing a lot of amp recording, or if you need something to use as a live mic as well as for recording in the studio.