This post focuses on a trick I learned in choir to avoid a large number of conflicting sybillances when stacking vocals.
If you’ve ever listened to a high school choir concert recording, chances are good that you’ve heard some outrageous sybillance happening. Getting fifty people to sing their esses at the same time is pretty much impossible. On thing I learned when singing in college is that you don’t need that many esses or hard consonants to make the word intelligable. In fact, only about 1/3 the choir really needs to sing them at all. If you’re singing ‘voice’, 2/3 of the choir can effectively drop the ess sounding c to sing ‘voi’. The result is a much cleaner presentation of sound. The same thing works in music production when layering vocals. Let one or two similar takes contribute the sybillant sounds while the others drop them. It works great. You can even edit out the sybillant sounds after-the-fact, if you’d like. Just add a short fade at the end of the word to make it sound more natural.
I did this in my song Vocal from my album, Sonoluminescence. You can listen to it here. I dropped almost all of the ess sounds from ‘voice’ in the backgrounds.