Once we have recorded the vocals, we need to edit them and process them with effects. Do we need to apply effects during the recording stage? What are the effects that we need to make a good vocal production? This article gives basic answer to these questions, along with a few suggestions for software plugins – paid and free. An introduction to the basic use of pitch correction, equalization, reverb, compression, double tracking and mix automation.
Effects during the recording stage ?
Do we need to use compression or equalization to the input signal that is being recorded, at the recording stage?
When using tapes, compression was useful because the headroom was limited and we did not want unexpected spikes to cause trouble. Nowadays when recording systems offer much headroom, there is no need to use EQ or compression before working with the signal during the mixing stage.
Recording the signal as it is, without any effects gives us more flexibility to work with the sound later. We cannot undo the compression off an already compressed signal, but during mixing we can try compressing it and undo it if we don't like it.
If pitch is a problem, Antares Audio Auto-Tune is a popularly used pitch correction software that does automatic pitch correction. If you are using autotune, it is better to set the exact scale of the song instead of the chromatic scale option. Then set a very slow correction speed. You can also vary the correction speed or even turn off the plugin as the need be between different places of the signal.
Celemony Melodyne is probably a better option. This software lets you change the pitch on a graphical interface. It lets you do more serious work with more accuracy especially if there is much work to be done with the pitch. Melodyne comes as a $49 entry version too: Celemony Melodyne Essential
Using shift pitch for pitch correction. Less serious pitching issues can sometimes be resolved by processing individual words using a pitch-shift algorithm to push them up or down by the necessary few cents. You can even automate the amount of shift applied to different words or phrases if you have the patience.
EQ for SM58 vocal recordings and vocal recordings done using condenser mics is different. Condenser mics have better high frequency response, while dynamic mic sm58 vocal recordings will need more sizzle and air to be added to it.
- Low frequencies which don't contribute to relevant audio information can be cut away at around 80 to 150Hz using a high pass filter.
- Boxy sound and muddiness be treated by working with the 150 to 600 Hz range.
- 3000Hz is the frequency for clarity and harshness at the same time.
- 8000 Hz adds to the sizzle.
- 12kHz through 16kHz is responsible for the 'air' or classy feeling of recordings.
Using two different reverbs is good for the vocal sound. One short plate reverb and a longer ambience reverb. Using short reverb lengths without making the effect obvious, is the more popular taste these days.
Cutting away the lower frequency range of the reverb can make it less obtrusive on the mix. Use predelay on the upfront plate reverb so that the reverbs starts acting some time after the word sounds, thus keeping the syllable clear.
Double tracking of vocals adds a likeable thickness to the vocals. Best way to double track is by singing the same part twice. There are plugins which will create similar effect or you can use the same vocal track and manipulate it to fake the sound by introducing pitch and time variation.
- copy the vocal to a new track
- add a pitch correction software to the second track to make the pitch of the singing in the second track slightly different.
- Add a delay to the second part to avoid phase related troubles and to add to the effect of the track being different from the first one
Compression on vocals
Keeping the vocal level nice and even is generally done with the aid of a compressor, aiming for around 6-8dB of gain reduction (using a ratio of between 2:1 and 6:1) on the loudest points in the track.
The optimal attack and release time settings depend on the type of compressor or plug-in you are using. If you're unsure as to how to set these, take a peek at some of the presets and see what values they used, but don't expect a preset to work without further adjustment, as the correct threshold setting always depends on the level and dynamics of the signal being processed. Here are some audio compressor settings to start with, based on the main two uses of a compressor.
Get familiar with automation in your sequencer, to work with the vocal dynamics. Zoom in and 'draw the automation lines' to precisely adjust the levels of phrases, words or syllables. Use automation to adjust breath sound levels or remove them. Use cross over to smoothly join parts. Each parameter of plugin effects can also be automated to get the right vocal sound.
Mixing – Subjective decisions
- Always mix at a volume so that conversations are audible without strain. A mix that sounds good in low volume will sound good in high volumes while the opposite is not true.
- Stand outside the mixing room and listen to the mix. The perspective difference will help us notice the level relations better.
- Use reference CDs to 'remember' how loud the vocals in published songs in our genre are.
The Art of Mixing: A Visual Guide to Recording, Engineering, and Production has been in publication for quite some time. The book explains the mixing process very well using visual representations, giving clear instruction and information to start with and complete a mix.