The vocal booth is a common image when it comes to modern recording. To the uninitiated, a studio isn't a "real" studio until it has a vocal booth. But is a vocal booth really necessary, or even desirable, for a typical project studio?
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| Vocal booth |
For large, commercial studios a vocal booth makes sense. A facility like this will be large enough that even the "small" booth will be the size of many average home or bedroom studios, and can be well-treated to sound good. Having a large vocal booth lets the engineer isolate the vocalist during full-band tracking, using a sensitive condenser or ribbon microphone while drastically cutting down or removing bleedthrough from the rest of the band.
But even in large facilities, engineers and producers will often have the artist track their vocals in the control room. Some producers even prefer tracking vocals without headphones at all, instead playing the backing tracks through the monitors. Proponents of this method feel it's easier to get great, passionate vocal takes this way, and there are methods you can use to control bleed (see the sidebar Getting Rid of the Bleed below).
So even in a large studio, building and using a vocal booth makes sense only if you are able to make it large enough to sound good, and you want some amount of room sound on the song you are tracking. Or if you need isolation to track vocal takes while the rest of the band plays at the same time.
In contrast, a small private, project, or home studio is often of the one-room variety, and space is usually much more limited. Many recordists use a spare bedroom or a finished basement room. In such cases the most common mode of production is to build the tracks up, overdubbing one layer at a time, and not full-band tracking.
Vocal booths in studios like these are typically closet-size 'rooms,' often installed in the back of a control room. The booth is often made dead, with a thin layer of moving blankets, foam or fiberglass covering all interior surfaces of the booth. The result is a dead sound, which is desirable. But because of the small size and lack of bass trapping, many vocal booths are also boomy, which is not desirable and is, in some ways, worse than an untreated room.
These booths are so small, with all walls in such close proximity to both the sound source and the microphone, that peaks and deep nulls from comb filtering cause a jagged room response varying as much as 30dB throughout the entire frequency range. The effect of comb filtering is why small room ambience is always bad ambience - music recorded in such rooms has that boxy, small room sound that won't be fixed by $2,000 mic preamps or microphones. Compression usually makes the problem even worse.
The best treatment for small rooms approaches 100 percent coverage to get rid of as many reflections as possible. But it's also important to remember that small rooms need proportionately more bass trapping than larger rooms. So now you not only need to cover most of the walls and ceiling to deaden the sound, but you also need at least two to four corner bass traps as well.
When an enclosed booth really is needed for more isolation, it's better to use absorbing panels rather than rigid walls.
If you have the vocalist sing with the monitors in the control room going full tilt, the sound from the monitors will bleed into the vocal microphone. The following polarity trick will help reduce this.
After recording a take, record a dry take with only the monitors playing, and the performer remaining silent, onto a spare track labeled "bleed track." It is very important that you record the monitors without moving the microphones or adjusting the volume or the preamp gain, and that people in the room not make any noise while recording the bleed track. This will produce an identical copy of only the bleed that went into the mic during the vocal take.
Reverse the phase (polarity) of the bleed track and mix it with the vocal track with the gain on both tracks set the same. This cancels out the bleed in the main vocal take. If everything sounds as expected, render the two tracks into a new single track, and archive or delete the original source tracks.
Place the mic diaphragm facing your lips (sometimes off axis, if necessary). Listen with your headphones for the subtle differences. Try close (two or three inches) or mid-distance (one foot) mic’ing, depending on which sound works best for your track. Always use a pop filter in front of the mic to tame your “P” and “T” sounds. If you don’t own a pop filter, you can make one from scratch with a sock or stocking cap stretched over a wire hanger.
The acoustic problems aren't limited to the booth, either. The presence of the booth just makes the control room smaller, which is never good. A booth in the front of the room is even worse because it disturbs left-right symmetry, which damages monitoring clarity and imaging. It simply is not worth compromising your listening room in order to install a vocal booth that will produce questionable results.
In general, vocals are best recorded totally dry. It's easy to add reverb and ambience when mixing, and you can change your mind later about the amount and quality of ambience mix. A vocal recording with any kind of room ambience - good or bad - cannot be made dry again, if you find you don't like it (or that it doesn't fit the mix) the next day.
A PVB or also helps to a surprising degree with isolation. Careful attention to mic placement and pickup pattern along with the PVB's orientation can produce startling results. Admittedly, a PVB will not get rid of crying babies and barking dogs, but a booth has to be very well constructed, with a lot of mass and insulation in its walls and door, and be completely airtight to completely block loud noise anyway.
One potential problem with one-room recording is ambient noise, usually caused by a computer or fans in musical equipment. If you have this problem in your studio, a PVB placed properly between the musician and the noise source can reduce the noise that gets into the microphone. Top
So in nearly all cases, we recommend that most small studio owners not build a vocal booth, and instead track overdubs in the control room or the one-room studio. This is simply a better way to track vocals, that also leaves the room in better acoustic shape for mixing.
