Vocals are a tricky part of a mix. The need for clarity often prevents any major effects being added to vocals as hearing the lyrics is as important as the melody which drives them. This post is going to explore adapting vocals to go beyond the lyrics, using effects methods that may not normally be heard in a conventional track. You can obviously take these effect ideas as-is, or more subtly, mix them underneath the main vocal track as an underlying effect.
Noise Reduction as a Filter
Most noise filters work by sampling a portion of noise and taking the frequency profile which is then filtered out. An example would be if there was a tone at 1000Hz at a volume of 60dB, it would be sampled, and 1000Hz would be attenuated (turned down) by 60dB.
If we were to use this noise profile and move to a room without that tone, there would still be that dip getting attenuated but without the tone. This means any recording done with the noise filter activated will be missing 60dB of 1000Hz.
ReaFIR is a free plugin which allows noise subtraction by building a profile
it allows you to visualise the frequencies which are being subtracted.
This can make an excellent effect. Go about your area and sample small amounts of noise, traffic, kettles, lawnmowers, even speech. This will mean you can load these samples as a noise profile into the noise filter and it will remove the frequency profiles. By adding this noise filter to a clean recorded vocal track, it suddenly attenuates background noises that weren't there, eating into the frequencies of the singer's voice.
Obviously not every noise profile will have a nice effect on the vocals but if you go through enough, you may find a few good ones that completely change the sound and timbre of the voice.
Bitcrushing With Parameter Modulation
This is perhaps not too uncommon in certain dance music genres, however there is more to this than just destroying the quality of the sound. Try duplicating a vocal track and adding a bitcrusher to one of them. You could then simply mix it into the clean vocal or we could go further.
Reaper's parameter modulation is a great tool for controlling a
plugin's parameter with the volume of another track.
Most good DAWs allow a form of parameter modulation where the volume of one track modulates a parameter elsewhere, much like side-chaining. A guide to doing this in Reaper can be found here. If we use the volume of the clean vocal to play about with the bitrate or samplerate of the duplicated track we can get cool effects.
One of the things this could do is add distortion to the duplicated vocal when the singer is at their loudest, giving the sound a bit of grit. If you are able to inverse the modulation, they could sound more distorted when they are quiet, and get cleaner as they reach their louder notes.
Reverb With Parameter Modulation
Of course, parameter modulations aren't limited to bitcrushing effects, try modulating the wet volume of a reverb, or even the reverb length to the singer's volume. This saves manually cranking up the reverb for the choruses.
Reverbs such as Ambience (free) have plenty of modulatable controls
aching to be played around with.
You may want eery verses, thick with reverbs. Perhaps set an inverse modulation, where the reverb wet volume increases when the bass volume decreases (replace with whatever instrument is quieter during the verses).
Your DAW may even allow you to modulate the send amounts to the reverb for individual tracks allowing further control over what is sent to the reverb bus.
One of my favourite free plugins of all time is Glitch, a glitching effect which allows you to sequence a number of different glitches to the sound. This effect can go from subtle underlying glitches beneath clean vocals, all the way up to total reimagination and destruction of the sound. I find it particularly exciting to use on vocals as you are able to completely transform the sound into something that sounds incredibly complex, all with an easy to use interface.
If you want to retain the lyrics of a song you could add this effect to a separate reverb bus for the vocals or even parallel process so the words are still audible. Even try slowly mixing Glitch in on the sustained notes and pulling it back before the next word is sung.
It is also a great way to simulate the sounds a broken robot may make in sci-fi style audio, where the voice gets super glitchy.
Extreme Formant Shifts
If you want to change the apparent pitch of a vocal, without altering the key or notes sung, try playing about with the formant. This can be done using plugins such as ReaPitch which allow formant control.
With formant shifts you can change a vocal's gender by moving it up and down, simulating the deepness or squeakiness of the voice.
Formant shifts are great when parallel processing as you can simulate a voice with two tones. This cannot be done with recording two people, as a parallel formant shift is exactly in sync. It is often heard in films when a person is possessed and they have they normal voice mixed with a deeper formant voice.
If you modulate the formant of a vocal to an LFO or modulation parameter, you can get cool effects as the formant moves up and down, perhaps layered with the dry signal.
Finally, automating the formant on a vocal during a build up to slowly rise before a drop is a great way to increase the tension and energy of a track. This of course can be applied to other instruments too.