When done well, a live recording captures the energy and personality of the performance, along with the ambiance and (if desired) audience response. There are many different ways to record a live show, but regardless of the approach, a good recording starts with the right microphones, correctly placed.
By “right” I’m referring to mics that fit the particular application, taking factors such as pickup pattern and SPL handling into account. Mics tend to be categorized as “live” and “studio.”
Yet while it’s true that certain models are too delicate for live use, and other certain models lack the sonic characteristics sought in the studio, today there’s a plethora of models tough enough to handle the rigors of the live realm while delivering the desired audio quality.
There are also a wide range of types. Large and small diaphragm. Dynamic, condenser and ribbon designs. Cardioid, supercardioid, hypercardioid, and figure 8 patterns. Vocal mics, except when they’re used on instruments. Instrument mics, except when they’re used on vocals. Drum mics, except when they’re used on other instruments…
If you’re not up to speed on mic types and technology, I recommend a visit to Microphone World here on ProSoundWeb, which provides dozens of articles on these topics.
Before even thinking about mics and their placement for live recording, take a look onstage and see what can be done to maximize separation and isolation of instruments and amplifiers—from each other as well as the house and monitor systems.
A good multi-track recording consists of clean isolated tracks, and we can use a few studio tricks to help. Separate the backline amplifiers away from acoustic instruments and each other. Try pointing the amps in a different direction (like offstage) to minimize bleed. Better still, spend time and convince the musicians to actually turn it down (“just this once” for the recording).
We can isolate between loud sources with damping materials, and they don’t need to be fancy or expensive. For example, one trick I use is to set the boom of a mic stand to a “T” shape and then drape a packing blanket from my truck over the T. Viola! It’s a portable, adjustable-height gobo that can be placed between loud amps and other mics.
Plexiglass is another common way to isolate instruments onstage; a plexi shield around the drums and/or percussion can help keep the drum sound out of stage mics, while keeping the loud amps out of the drums mics.
Position stage monitors that are close to mics so that they play into a null spot in the pickup pattern of the mic(s). Better still, try to eliminate stage wedges and get the performers to use in-ear monitors. Try to close-mike instruments as much as possible in order to only pick up the intended sound.
In the live world, we tend to like cranking the gain up until it’s close to the red, but studio engineers often use only as much gain on a mic as needed to ensure a good dynamic range. The lower the gain, the less chance of picking up unwanted sound (and noise—remember, this is live).
Overheads on drums tend to pick up a lot of sound we don’t want, so bring them in as tight to the kit/cymbals as possible. On a loud stage I tend eliminate the overheads altogether and just close-mike the cymbals from underneath. This technique can also work well for straight-up live sound.
Keep stage rumble to a minimum. In addition to rolling off very low frequencies with EQ or high-pass filtering, I also make sure mic stands are in good shape and have rubber feet for isolation from the stage. If stage vibrations entering the mics are a problem, use shock mounts. When recording outdoors, keep windscreens handy.