Fig. 1. The spaces between phrases and words have been cut, with fades added to create smooth transitions.

Clean-up Remove the spaces between vocals to delete headphone leakage, mouth noises, etc., then add fade-ins and -outs to smooth the transition from vocal to silence (see Figure 1). Insert a steep (48dB per octave if available) highpass filter to cut the very low frequencies where subsonics, hum, mud, and p-pops live.

Dealing with Inhales Inhales are a natural part of singing; however with multiple voices, inhales often don’t occur simultaneously. For a more unified sound, pick two inhales that are in sync (or just one, if you don’t have two that sync), and delete the other ones. Adjust the gain of the inhale(s) so that they slide properly into the phrase. If you want to keep an inhale but it’s too prominent, fading in on the inhale can make it less obtrusive while still retaining an authentic vocal quality.

Fig. 2. The upper track has a major p-pop; the lower track had an equally bad pop, but the fade has tamed it.

The Dreaded “P-pop” Using lowcut filters, if you reduce the lows sufficiently to remove the pop, you usually reduce the voice’s resonance. Instead, zoom in on the p-pop (it will have a distinctive waveform) and split the clip just before the pop. Then, add a fade-in over the p-pop (see Figure 2). The fade-in’s duration determines the pop’s severity, so you can fine-tune the desired amount of “p” sound.

Notes That Don’t End at the Same Time If one note is short compared to a note with the correct length, split the short clip just before the last word, and use DSP to stretch it (e.g., in Cubase or Sonar, ctrl-click on the right edge and drag to the right). In some cases you can split a note during the sustain, stretch the end longer, and crossfade the split region to make a smooth transition between the main part and “tail.” This can give a more natural sound if you need a fair amount of correction.

A note that extends too long is easier to fix—just fade it so its length matches the “reference” vocal, or split during a sustain and move the end closer to the beginning, with crossfade enabled.

For a really uniform sound, group all the vocal clips together and add a common fade so that they all fade simultaneously (see Figure 3). This creates a super-precise vocal sound, but as you’re not processing the vocal itself, the sound is natural.

Fig. 3. Each word has been aligned to start at the same time, while a common fade time creates a common ending. Before the fades were added, each note had a different end time.

Busing I prefer not to mix a zillion tracks, so I like to set up aux sends to send all the layered vocals to a single stereo return. Not only does this make it a lot easier to mix, but you can also use a common signal processor (like a bus compressor set for a modest amount of compression) to “glue” the tracks together. A bused, individual stereo output also lends itself well to reverb, as the voices sound like they’re in a common acoustical space.

Is it Worth it? These tricks involve a fair amount of detail work, but the results are worth it. Smooth, consistent, polished background vocals make an excellent bed for the lead vocal while also giving it more importance— and as far as I’m concerned, there’s no more important element of any song than the lead vocal.