When "thickening" up lead vocals is it best to record a second take, or should you just duplicate the first pass? What are some other tricks to add dynamics to vocals?

To thicken the vocals, usually you record a second take. This is called "doubling the vocal". It sounds less mechanical than duplicating the first pass and sliding the second pass about 25 milliseconds earlier or later than the first pass. Pan both tracks to center. In Heavy Metal productions, it’s common to double the rhythm guitar, and pan the two parts all the way left and right.

John Lennon asked his recording engineers if they could double his vocals electronically. They did it with a tape recorder and called it "ADT" for "Automatic Double Tracking." You hear it on John’s vocal in "I am the Walrus". You can create the same effect with a DAW using the time-sliding method. A similar effect is called "Chorus".

A chorus stomp-box or plug-in delays the incoming signal about 15-30 milliseconds, adds it to the original signal, and varies the delay. The chorus effect varies its own delay; you don’t need another plug-in to do that. It sounds less mechanical than combining a vocal with its delayed replica using a constant delay time.

The most popular vocal effect is reverberation, which simulates room acoustics. Set the reverb time to about 0.5 second to simulate a small room, or about 1.6 seconds to simulate a concert hall. Or just leave the vocal dry (without reverb), as in "One Hand In My Pocket." Contemporary recordings tend to be drier than 1980’s recordings.

Fast tempo songs usually sound best with shorter reverb times. A popular vocal effect for rockabilly or rock ‘n’ roll genres is slap echo or slap-back echo. It’s a single echo with the delay set to about 130-150 milliseconds. It sounds better if you turn down the high frequencies in the delayed signal.

You can hear slap echo in Lennon’s vocal in "A Day in the Life" and "Instant Karma", and in most songs by Creedence Clearwater Revival. A slow repeating echo (delay time about 500 msec and some feedback to make the echo repeat), mixed very quietly under the vocal, can be effective for slow ballads.

Set the delay time so that the echo repetitions match the tempo of the song. Compressing the vocals is very common to keep their volume more constant. For starters, try a 3:1 ratio, 20 msec attack time and 250 msec release time. Gradually turn down the threshold until the gain reduction is about 6 dB. (Of course, these suggestions do not apply to all songs).

One vintage compressor plug-in that sounds great is the dbx 160. Vocal compression is used almost always with rock. For folk music, use gain riding (volume envelope automation) instead because it sounds more natural. If the singer’s "s" sounds (sibilant sounds) are excessive, use a multiband compressor set to compress only the band from 5 kHz to 20 kHz, where the sibilant frequencies are. Try a 1 msec attack time, 200 msec release time, and 5:1 compression ratio. Gradually turn down the threshold until the amount of sibilance sounds good to you.

Bruce Bartlett is a recording engineer, mastering engineer, and microphone engineer. He is the author of Practical Recording Techniques 5th Edition and Recording Music On Location. Please send Bruce your recording questions via L2PNet.com. Follow Bruce’s Blog

Originally posted 2009-09-08 14:38:18.