Vocal Recording Techniques

Last month we discussed ways to get a great performance from a vocalist, but this post is dedicated to getting a great vocal sound. Vocal recording has more nuances than recording other instruments mainly because of the plosives (the “b” and “p” sounds) and sibilance (the “s” sounds), but also because the voice has such a naturally dynamic range. Plus, there are as many vocal styles as people singing, and they all need a microphone that’s complimentary to their voice in order for it to maintain the center of attention in the track. That’s what makes microphone selection, among other things, so important in vocal recording.

Here are some tips taken from The Recording Engineer’s Handbook and the upcoming Music Producer’s Handbook to help you get a great vocal sound quickly and easily without any of those nasty side effects.

Lead Vocal Constants

There are a number of “constants” that we find in vocal recording. These are items or situations that almost always prove to be true. Just keeping the following in mind can save you a lot of trouble in the search for a sound that works for you and your vocalist.

Your mic selection, amount of EQ, and compression used is totally dependent on the voice you are recording.
The best mic in the house doesn’t necessarily get the best vocal sounds.
A singer who is experienced at recording knows which consonants are tough to record and knows how to balance the them against the vowels to get a good final result. A singer with this kind of experience will make you look like a genius.
With a good singer, many times you’ll get “the sound” automatically just by putting him/her in front of the right microphone. On the other hand, with a bad singer (or even a good singer that just doesn’t adjust well to the studio), no amount of high priced microphones or processing may be able to get you where you need to go.
In general, vocals sound better when recorded in a tighter space, but not too tight. Low ceiling rooms can also be a problem with loud singers as they tend to ring at certain lower mid range frequencies, which might be difficult to eliminate later.
Windscreens are actually of little use when recording a vocalist with bad technique. There are two different sorts of people in this category: the people who have never sung with sound reinforcement, and the people who have developed bad habits from using a mic on stage.
Decoupling the stand from the floor as well as the microphone from the stand will help eliminate unwanted rumbles. Place the stand on a couple of mouse pads or a rug for a cheap but efficient solution.

Just marking the floor with tape might get the vocalist to stand in the right position in front of the mic, but she can easily move her head out of position. An easy way to have a vocalist gauge the distance is by hand lengths. An open hand is approximately eight inches while a fist is about four inches. By saying, “Stay a hand away”, the vocalist can easily judge his distance and usually doesn’t forget (see Figure 1).

Figure 1 - Setting Vocal Distance By Hand.

Eliminating Pops, Lip Smacks, And Breath Blasts

No matter how great a mic might sound on a singer, a vocal track with pops, lip smacks, and breath blasts will still be deemed “bad sounding” by everyone involved. These are actually fairly easy to control with mic placement and a little experimenting. Here’s where to start if unwanted singer-generated noises are creeping into your vocal track.

Place the mic aiming above the lips (at about nose level) so the singer’s breath is right below the capsule (see Figure 2).
Move the mic up three or four inches above the singer’s mouth and point it down at the mouth. This also cleans up mouth noises and the nasal sound that some singers have a problem with (see Figure 3).
If popping continues, move the mic a few inches higher and/or farther away.
If popping continues, turn the mic slightly off-axis.
If popping continues, change the mic’s directional pattern to omni.

Figure 2 - Vocal Mic Placement Using A Large Diaphragm Condenser Mic.

Figure 3 - Vocal Mic Placement Aiming Down.

Microphone Selection

That last point about changing the mic’s pattern to omni-directional can be a life-saver and can even sound better on a vocalist than a directional mic. For years I was hired by a top producer because he liked the vocal sounds that I got for him, but the secret all along was that I was always recording the vocalist using an omni pattern. Which brings us to a good point to remember:

Use what sounds good, not because other people use it or it looks good.

All too often, engineers and musicians will use a mic because it’s a “vocal mic” or they read that someone has used it on their favorite singer. First of all, don’t believe everything you read because engineers are notorious for giving out less than truthful information in an effort to protect “their sound.” Secondly, a mic that works well for a singer on one track may not work on another, since the instrumentation, arrangement and dynamics of the song may be different. Lastly, there are many misconceptions about microphones that are supposedly “perfect for vocals.”

Believe it or not, large diaphragm mics are not always ideal for vocal recording. Just as many great vocals tracks have come to life by way of a dynamic mic like a Shure SM-7 (or even an SM-58!) or a small diaphragm condenser like a Neumann KM-84/86 as with a classic large diaphragm condenser. To again quote the second constant stated above, “The best mic in the house doesn’t necessarily get the best vocal sounds.”

The Hanging Microphone

Everyone has seen the photos of the vintage large diaphragm tube mic hanging upside down in front of the vocalist (See Figure 4). Many engineers think that it’s a fashion statement or some sort of convenience, but there really are several good reasons for placing a mic this way. Here are just a few things to consider:

Figure 4 - Hanging Tube Condenser Microphone.

Much of the reason for hanging a mic upside down is because many of the early studio microphones used tube electronics. The heat rising from the tube can cause the diaphragm to change temperature over time, which will change the sound of the mic. Placing the tube above the capsule will let the heat rise without passing over the diaphragm.
An excellent byproduct of singing slightly upward into a mic because it’s positioned upside down is that it forces the singer’s airway open and encourages a full body voice. Take a deep breath and sing a low note. Start with your chin to your chest and slowly lift your head until your chin is about 15 degrees above level. Hear any difference?
Maybe even more important, the mic can be positioned so the singer is less likely to direct popping air blasts into the mic.
It’s easier for the singer to read any music or lyrics since it’s out of the way.

Vocal Mic Placement

Just like with any other instrument, microphone placement is the key to a great vocal sound, even more so than the mic selection. Here are a few items to consider when you’re first placing the mic.

Move the vocal into the big part of the studio. All vocals and instruments sound best when there’s some space for the sound to develop. You can cut down on any unwanted reflections from the room by placing baffles around the singer.
Place the mic with the capsule just about even with the singers nose. You get very little blasting from breath that causes pops. If popping continues, turn the mic slightly off-axis. The distance will vary widely depending on the singer, the type of sound you’re trying to get, and the SPL-handling capability of the mic. Somewhere between four and twelve inches should work in most cases, but use the hand positioning to keep the singer at the same distance (see Figure 1). For a whisperer, get even closer than four inches, and use fingers to determine a distance that the vocalist remembers.
Use the mic as a decoy and put the recording mic up a couple of feet behind it if a vocalists has trouble staying in the right place or wants to eat the mic. While the sound might be a little more distant, it will also be a lot more consistent.
Many vocalists are just more comfortable with a hand-held mic like they use on stage. Don’t be afraid to give them an SM58 if it makes their performance more comfortable and easy. More great vocal recordings than you realize have been done on a hand-held mic.

Background Vocals

Background vocals are different from recording lead vocals since they’re usually comprised of more than one singer, therefore the recording technique is a little different. Because of all the possible variations in background singers (number of singers, male or female, male and female, etc.), the approach to recording has to come form a slightly different mindset.

Background Vocal Constants

Just like recording lead vocals, there are a number of constants that usually hold true when recording background vocals, such as:

The better or more unique a lead singer is, the harder it usually is for them to sing background vocals that blend well with other singers because the voice is so recognizable.
If the lead singer is singing all the background parts or is part of the background vocal ensemble, using the same mic that the lead vocals were recorded on will cause a buildup of any peaks in the singers voice, mic, or the room. Try to use a different mic for backgrounds to avoid this.
If the singers have trouble blending or singing in tune, removing one side of the headphones, or at least putting it slightly back on the ear, sometimes helps them adjust since they can then hear the vocal blend acoustically.
The best background blends usually come from having multiple singers positioned around a single mic or stereo pair.
Large diaphragm cardioid condensers are used because they combine a proximity effect and slight midrange scoop along with a slight lift in the upper frequency ranges. This accentuates the “air” portion of the sound (or conversely, scoops out the “non-air” portion) which helps the background vocals sit better in the mix.
The microphone does not always have to be a large diaphragm condenser however. Sometimes the natural compression of both volume and transients offered by a dynamic mic will keep the vocal much more under control than a condenser.
Try to do something a little different on each track. A different mic, mic preamp, room, singer, or distance from the mic will all help to make the sound bigger.

Placement

Start with a large diaphragm condenser in omni about thee feet away from the vocalists.
The standard jingle production technique - Stack the overdubs with three vocalists on a pair of mics in an X-Y configuration or use a stereo mic. Have them sing each part in unison, then change their positions around the mic and double. Do the same for all parts.
For extra thick background vocals (a la Def Leopard), cut four tracks of the root, two tracks of the harmony, then one or two “whisper tracks” of each part. Compress the whisper tracks heavily. They’ll add the “air” of 100 overdubs.
Many of the techniques used for recording a choir also work for background vocals (such as the Blumlein pair).

VoiceOvers

It’s easy to forget that there’s more to audio recording than music. Voiceovers for television and movies, commercials and audio books (to name a few) require yet another approach since the nature of the recording is different.

The Constants

The worst thing that can happen on a voice-over is a pop, and therefore it must be avoided at all costs.
Room requirements for VO work are in some ways less demanding than for a music recording space. The room should be acoustically dead (not too dead though), but what’s most important is that it must be really quiet. Nothing will ruin a spot or story quicker than small room reverberation on the VO or an noise from the outside world.
Even among professional voices, there are some whose voices that will sound good on almost anything, while others need a specific mic to get the right sound. If you’re recording the average person, the variances increase because of the lessor skill level.
Your mic selection, amount of EQ, and compression used is totally dependent on the voice you are recording.

Placement

Here’s the classic way of recording VOs - place the mic from four to eight inches from the talent (a fist or extended hand length) and off axis about 45 degrees to prevent popping. Compress about 9 to 12 dB at 4:1 ratio with attack and release as fast as possible (see Figure 5)

Figure 5 - Voice Over With An RE-20.

Other Vocal Tricks

There are several vocal overdubbing techniques that are commonly used that every engineer and producer should be aware of. Although the following techniques refers to vocals, they can be used for just about any instrument.

Vocal Doubling

Doubling a lead vocal has been used for as long as there’s been multitrack recorders. The Beatles did it way back when they were using only 4 track magnetic tape and really didn’t have a track to spare, which tells you how powerful a tool it can be.

Doubling a vocal (having the singer sing the exact same line or phrase twice and playing back both parts) works for two reasons; it makes a vocal sound stronger, and it masks any tuning inconsistencies in the part.

While the doubling technique can work for a great number of vocalists, sometimes it just doesn’t sound good if both vocal tracks are replayed at the same level. Try adding the second vocal at 6 to 10dB less than the track you deem the strongest. This will add a bit of support to an otherwise weak vocal without sounding doubled.

Vocal Stacking

An offshoot to doubling is vocal stacking, a technique normally used on harmony background vocals. Like doubling, stacking can make a harmony vocal part sound stronger while smoothing out any tuning inconsistencies.

An example of vocal stacking would be a three piece vocal group singing a three part harmony part. After their first pass is complete, they’d double the exact parts singing it exactly the same way, then even triple track it or more, all in an effort to get a bigger fuller sound. One little trick that makes a stack sound bigger is to have the vocalists take a step back from the mic with every vocal pass while the engineer increases the mic gain to compensate for the distance (in other words, the level meter reads the same for both). The increased ambience of the room will naturally enhance the sound without having to resort to artificial means.

Another trick would be to have the vocalists change parts with every pass. In other words, the vocalist on the highest part of the 3 part harmony would move to the lowest, the one on the mid part would move to the highest, and the low part would move to the mid part. Of course, this assumes that the vocalists are pros and capable of changing vocal parts without too much of a problem, and that their voices are actually capable of performing the new parts.

Vocal Comping

One of the best techniques for obtaining a great vocal is to compile a master vocal track with bits and pieces from a number of previous passes. This is known as “comping” and has become a standard method of obtaining a great take of just about any part.

Comping is also a method preferred by a great number of vocalists since it makes their job fairly easy. After they warm up, have the vocalist sing the part at least three times (the more the better), then send them home. It’s now up to you to comp a master track together.

Tips For Comping

While you can comp a track from only two passes, the more passes the better, up to a point. Too many passes gets confusing and takes too much time to sort through. The ideal number of passes seems to be five or six, although many producers will have the vocalist sing the song until she almost gets it prefect before moving on to additional passes for comping. Regardless of how many passes and the quality of the performances, if you take good notes during each pass, you’ll find your comp can be finished in no time.

Make no mistake about it, note taking is the key to this process and it’s best done while each vocal pass is being recorded rather than during playback later. While it’s possible to comp individual words or even syllables, comping by phrase is the easiest. Here’s how to do it.

Get a copy of the lyrics. Make sure that the song is divided into clear phrases.
As the vocalist sings, you’ll make the following marks after every phrase:
↑ sharp, ↓ flat, G for good, VG for very good, X for bad, ? for “I can’t decide”
You’ll place a 1 for the “first pass” or use the name of the track and make your marks on that line. Do the same for each pass.
After each phrase that the vocalist sings, place a mark underneath (see figure 7) to indicate your rating.

Figure 6 - A Comp Sheet.

By the end of the vocalist's last pass, you’ll have a pretty good idea of what phrases are the keepers. You’ll also have an idea of which phrases don’t have an acceptable take, and you can ask the vocalist to just give you that line until you have what you need.
After all the passes, see if you can piece together a vocal of all VG phrases. If a phrase with a VG mark doesn’t sound as good as you originally thought, go to the G marked vocals and see if one is acceptable. If you can’t find one that works that’s marked, VG or G, go through the other passes to see a “?” pass works. If you still can’t find an acceptable take, go through the passes again and listen to the passes that you marked with an X to see if you change your mind about one of the phrases that you considered unacceptable before.
If you still have a phrase that isn’t as good as you need, either comp by word or syllable or use autotune to get what you need.

Comping is standard session procedure these days that’s used not only on vocals, but tracks of all sorts, so it pays to get good at it. The technique will give you great results and save a lot of time as well, as well as all the other tips previously mentioned.