Specifically Speaking
Vivien:
I don't post much, but you asked for some specific reverb settings for a capella vocals, so I'm gonna' throw in my 2 cents.
(1) There's no law mandating the use of reverb...(i.e., ya' don't hafta' add it if ya' don't wanta' add it). Depending on the type of room you're recording in, and what type of mics, and how far away from the mic the vocalist(s) is/are, and about a ka-billion other factors, your vocals may sound fine "as is." This is cool when it happens, but my experience is that the odds are against it. SSSsssoooooo....
My Own Personal Favorite a capella vocal reverb setting:
If you're using Cool Edit, (that's where I am, right?)...try altering one of the preset reverbs as follows: The preset is the one labelled "Vocal - Nice Presence." Click on it, then change the numbers to the left as follows:
Total Reverb Length (1500)
Attack Time (90)
Hi Frequency Absorbsion Time - (1500)
Perception - (65)
Original Signal (no change)
Reverb Wet (between 10-20%)
No SINGLE reverb setting is right for all situations, (I know you know that)...but on mid-tempo a capella tracks, this altered preset has worked best for me. If the tempo is slower and the number of vocalists is smaller, I increase the "attack time" number and the "reverb wet" percentage.
Also, my PERSONAL preference is to mix the vocal tracks together completely dry before adding any reverb- or, I should say, mixing the vocal tracks that are occupying the same position together...I don't mix the backups together with the leads...does that make sense? I guess in theory, it shouldn't matter if you add reverb to each track individually before mixing down, but my ears tell me it makes a difference (incidentally, my ears also tell me it makes a difference if you record 4 vocal tracks on one mic as opposed to recording 4 seperate vocal parts onto 4 tracks and then mixing, but that's another topic altogether).
If you're mixing up to 7 vocals, my guess is that you're wanting some of the vocals to be supporting a lead or leads, right? (7 part "harmony" would scare me). If that's the case, then you might try cutting some EQ between 5K-7k on the vocals that you want to blend more into the background. While reverb can act like glue to blend vocals, a lot of times EQ will help more than reverb. I see a lot of advice in these threads about using effects like "chorus" to make a vocal stand out...but to me, chorus in particular sounds unnatural, which is probably not your goal if you're recording a capella vocals. Ozzy can get away with it, but he doesn't do a whole lot of a capella 4 part harmony. Instead of reverb and chorus, try using direction (i.e., pan some left, some center, some right, somebody said that already), and try using EQ (cut between 5-7k to make 'em blend, and boost in the same area to make 'em sound different - like when you're recording your own backups to your own lead vocal and you want them to sound not quite so "it's the same guy singing"-ish.
Man, I guess that was about 4 cents worth. But the reality is that it may be worth 0 cents for your particular situation...I hope you get something out of it...because my fingers are tired.