How to Record and Mix Vocals
The human voice is extremely complex. Man made instruments, such as the piano, flute or even the guitar, can be emulated through sampling and synthesis successfully. Vocals, however, vary so much in tone, character and dynamics that they are extremely difficult to reproduce synthetically - at least to a convincing level. Subsequently, although it is possible to create music entirely from synthetic instruments through the use of plugins, if you want a human sounding vocal on your track, there is no substitute for recording the real thing. In this post, we'll cover the fundamental techniques required to get professional sounding vocals from day one.
A Great Vocal Starts with a Great Singer
Everyone can sing, but not everyone can sing well. A great sounding vocal is extremely subjective, but it's important that the basics are in check: can the vocalist sing in tune, do they exercise proper breathing technique, have they warmed up correctly? We'll leave the decision on whether or not the singer can actually sing up to you, but make sure you consider the final result before pressing record. It is extremely difficult to correct a bad vocal performance in the mix, and although small adjustments can be made to pitch, timing and EQ during the mix, it's imperative you get a good performance from the start.
Advice: You can help yourself by warming up and making wise choices about your diet. Vocal coaches will typically advise drinking lukewarm water or herbal tea before a performance and will advise against anything that could irritate the throat, airways or stomach - this includes alcohol and caffeine I'm afraid!
Selecting a Microphone
Typically, studio vocals are recorded using a large-diaphragm condenser microphone. One reason for their dominance is their unique tonal characteristics. Unlike small-diaphragm condenser microphones, which tend to sound more neutral, each large-diaphragm option on the market will impart its own individual tonal stamp to the recording. Such variation allows you to match each mic with different singers to complement their voice. If your budget can stretch to a couple of mics, it's a good idea to invest in 2 distinctly different sounding models. The obvious choice would be to purchase one bright and airy option and a warmer alternative.
It's worth emphasizing that expensive does not necessarily mean 'better' in this circumstance. It is more important to consider the tonal identity of the mic and how suitable it is for your vocalist than it is to consider the price tag. For example, you could have a vocalist with a naturally throaty quality to their voice, and if your microphone of choice just so happens to accentuate this, the mic will be unsuitable regardless of cost.
If you do choose a condenser mic to record your vocals, you'll need a pop-filter to keep explosive consonants from distorting the capsule. The most common culprits here are 'p' and 'b' sounds, which can send a gust of air into your mic. A good quality pop-filter placed directly in front of the mic will keep the offending sounds under control without affecting the tone of your recording.
Consider a Dynamic
Although large-diaphragm condenser mics are universally considered the standard for studio vocals, there are exceptions. Some engineers will often choose dynamic mics for particular singers or musical genres. Typical examples include heavy rock, metal, or rap vocals where the detail and high-frequency response of a condenser microphone can become a hindrance.
Consider a Ribbon Mic
Ribbon microphones were once the industry standard for recording; however, earlier ribbon microphones were notoriously delicate and eventually fell out of favour to more robust modern condenser mics. Selecting a ribbon microphone can help smooth out the high frequencies on vocals thanks to their warm tonal qualities, and thankfully, modern versions are far more robust.
Your takeaway from this should be as follows: try as many microphones as your budget will allow. Getting the tonal character right at this stage could make or break your entire track, so it's worth your time and investment.
There are 3 common polar patterns for you to consider when recording vocals: cardioid, omni-directional, and figure-of-eight.
The most commonly used polar pattern for recording vocals is cardioid, which is more sensitive to sound arriving from the front of the mic than the back. Cardioid mics have the advantage of reducing ambient noise; however, they will also colour the sound more than an omni-directional design. The most obvious example of colouration is through the proximity effect, whereby low frequencies become more pronounced as you move closer to the mic. You will also notice small changes in tone if the singer moves off axis.
Omni-directional microphones will produce a more 'natural' or 'open' sound, but they will also capture more reflections. If you have great room ambience that could compliment the recording, or if the room is very 'dry' or 'dead' sounding, an omni-directional mic could produce a more natural sound. In most cases, particularly in home recording studios, the drier, intimate sound of a cardioid is easier to fit within the context of a mix. Natural reverb can sound great when it's done well, but if you're unsure, it's far safer to reduce it and add space through a reverb plugin later.
Last but not least is the figure-of-eight. Commonly found in Ribbon microphones, a figure-of-eight polar pattern picks up strongest from the front and back of the mic and rejects from the sides. Through strategic microphone placement, the dead zone created either side of a figure-of-eight mic can be used to your advantage when recording a singer that plays guitar at the same time.
Mic Positioning & Distance
Somewhere between 10 to 20 centimetres away from the mic will generally work for most voices. If you are using a cardioid mic, beware of the proximity effect as the singer moves closer to the mic. Most importantly, try and keep the distance constant throughout the performance, as any change in position can drastically affect the tone.
Finally, sibilance can be an issue when recording vocals. If the vocalist produces very pronounced 'S' and 'T' sounds, try moving the microphone slightly lower so that it is not in direct line of sight with the singer's mouth.
(Height will vary the tone when using a cardioid mic. Experiment with different heights to get the best balance of tone and controlled sibilance)
Now that you understand how your microphone is picking up sound, you need to consider how it works within the context of a room. Condenser microphones are very sensitive and will inevitably pick up reflections from your room. These reflections will be captured in addition to your direct sound, and unless you are lucky enough to have a professionally designed acoustic space, it's unlikely that they will flatter your recording. In most cases, it is better to control the amount of reflections in the room; allowing you to concentrate on capturing a good quality direct sound.
Failing to control room reflections is where most home or project studio recordings fall down. You can invest as much money into a great quality microphone as you want, but if you fail to control reflections from the room, no amount of improved performance from the mic will improve the result. The good news is, controlling acoustics doesn't have to be expensive. Here's how you can make some immediate improvements to your recordings:
Hang a Duvet
It might not look pretty, but it works. The quality of your direct sound can be vastly improved by hanging a duvet behind the singer. This technique makes sense when we think back to our cardioid polar pattern. The cardioid pickup pattern of your mic picks up the strongest signal from the front, so by hanging a duvet behind the singer, we can absorb room reflections before they enter the microphone.
Consider a Vox Guard
You can further improve your recordings by using a reflection filter. Portable solutions such as Primacoustic's Vox Guard fit directly to the mic stand and will significantly reduce reflections from the sides and back. When used in combination with a duvet as described above it is possible to achieve great results for very little money.
Consider Treating Your Room
If you're aiming for a more professional look and feel to your recording space, it's worth considering acoustic treatment kits. Controlling reflections more permanently across the entire room will yield benefits to your entire production process - from recording right through to mixing and mastering. In addition to the aforementioned Vox Guard, Primacoustic also make pre-designed kits for a number of different room sizes to get you started.
With your microphone weapon of choice selected and the room acoustics all in check, you're finally ready to capture that all important performance. Now is the time to make your vocalist comfortable. The happier the singer is, the more likely they are to deliver their best performance. Take a few extra minutes to get the headphone mix right so that they can hear the track and their performance easily. Adding a little reverb into the headphone mix at this stage can make the world of difference to a singer's confidence and pitch. Just be sure to capture the dry sound only so that you can have full creative control during the mix.
Comping Your Vocal Takes
Even the best vocalists make mistakes. In addition, some takes will inevitably be better than others. For this reason, it's good practice to record several takes and then combine the best bits into a master track, or 'comp'. The old school way to perform this task was to record each take on a separate track and then cut and paste the best parts onto a new master track. This process was quite laborious, and thankfully, most modern recording software comes equipped with some form of comping tool to enable easy access and selection of multiple takes within the same audio track.
When selecting the parts you want to keep, be sure to swipe carefully. If you cut off the beginning or end of phrases, your final result will not flow seamlessly. If you only cut in between phrases, your edits shouldn't be audible, and the result should sound as though the vocalist performed the whole track in one take. (See example from Logic Pro below).
For the vast majority of popular music, the vocal is king. Because of this, it has to maintain a constant space and level throughout the track. Although there is no single formula for mixing an excellent vocal, there are a few standard practices that work for a broad range of styles. Mild EQ, compression, and reverb are all typical for a lead vocal. Here are some examples to start with:
Ideally, you'll have invested your time wisely when choosing the right microphone for the singer's voice. In any case, a mild amount of EQ can further enhance your selection and help position the vocal in a mix. If you recorded your vocal using a cardioid polar pattern, it's likely to benefit from a little cleaning up in the low frequencies. Try cutting a few dB around the 300 - 600Hz area to clean up a muddy vocal. It's also worth using a high-pass filter to roll off frequencies below the 100Hz mark. These low frequencies aren't relevant to most vocal sounds and reducing them will help clean up unwanted low-frequency rumble.
High-frequency treatment very much depends on your microphone selection and production preference. If you selected a large-diaphragm condenser microphone with a bright sonic character, boosting in this region could over do it. If you would like to add a little more presence to the sound, a small boost around the 3 - 7KHz area should be enough to add more clarity. A broad boost from 8KHz and up can add 'air' and 'sizzle' to the sound.
How or when to use compression for vocals will divide opinion among engineers and producers. More aggressive styles, such as heavy rock will often utilise very extreme compression. On the other hand, purists looking for a more natural tone will typically advise keeping compression to a minimum; instead favouring the use of automation to control volume levels.
For a mild compressed effect, try a ratio of around 2:1 - 6:1 and adjust the threshold so that it catches the louder peaks. If it's a more extreme effect you're after - choose a ratio of between 3:1 and 7:1 and adjust the threshold so that the processor is nearly always acting on the voice. The greater the gain reduction, the more important it becomes to set a short attack time. If the attack is too slow, heavy compression can overly exaggerate sibilant sounds. A good start with attack and release settings can be to check out the plugin presets first. These will give you an idea of typical settings from which you can tweak to fit your needs.
Generally speaking, a vocal reverb should achieve two things:
Your primary concern here should be to give the impression your vocal was recorded with everything else. When recording individual tracks one at a time, the final result can leave each piece sounding estranged from one another. The problem becomes particularly evident when everything has been close mic'd using a cardioid polar pattern. You can use reverb to give each disconnected track some shared acoustic characteristics and a sense of belonging to the same record.
Modern reverb plugins come with a wide variety of presets to get you started. It's worth investing a good amount of time to narrow down an appropriate fit for your mix, but remember, a preset will rarely fit the bill perfectly. Adapting reverb to suit your track is a complicated topic in its own right, but on a basic level you'll want to tweak a few critical parameters as follows:
Pre-delay - This technique simply delays the onset of your reverb reflections by a specified amount. Left untouched, or with no pre-delay enabled, early reflections can alter the tone of your direct sound. Additionally, the listener is positioned much further away from the vocal. A popular technique is to set the pre-delay in time with the eighth or sixteenth note, this method retains the intimate direct sound while adding dimensional size.
EQ - Equalisation is normally added to the return signal and can help to give your reverb 'focus'. A typical starting point would be to cut low frequencies with a high-pass filter and also consider cutting high frequencies to some degree too. In combination, these cuts will help to retain focus and punch at the low-end while further emphasising the distance between direct and room sound. Once you have the high and low-end set, consider shaping the reverb further using well-placed EQ cuts to reduce any unwanted resonances. Your aim should be to create a subtle room ambiance that fits tightly into your mix.
For a little extra zing, you could try adding a plate reverb as they have a distinct classic character without sounding like any particular room or space. When blended with a subtle room ambiance as described above, it is possible to produce a thick, warm sounding vocal that blends well with the entire track while standing out as the key focal point.
The Bottom Line
Getting a vocal to sit just right can be one of the more challenging aspects of mixing. It takes practice, and a well-trained ear to get it spot on. Follow the advice in this post for an excellent starting point and always reference your work against a commercial track that you really respect. Finally, keep in mind that there are no real rules, and if it sounds good, then it is good.