No doubt there are many ways to record backing vocals. This is one method of recording and processing backing vocals that works very well for pop music.
When it comes to tracking it is a good idea to try and choose a microphone that sounds different to the lead vocal microphone, particularly if the lead singer is doing the backing vocals too. It will help to sonically differentiate the lead vocal from the backing vocals. It’s good if the lead vocal microphone you choose has a bit of a bump in the top end of its frequency response curve. This will bring out the lead vocal in the mix without you needing to go and use EQ. It is also true that if you choose a flatter sounding microphone which doesn’t have the top end bump in the frequency response for the backing vocals this will naturally place them behind the lead vocal in the mix. This is an example of how you can get a sound that will be appropriate for the mix through the use of hardware rather than having to use post-recording processing. This is referred to as ‘capturing the sound at the source’.
There are essentially three kinds of backing vocal that can be tracked behind a lead vocal, (1), Thick textural ooo’s, or ah’s, or long notes of some type, or (2), vocal lines that sing around the lead vocal and fill in the musical gaps, and (3), harmonies that run parallel to the lead vocal. These are the most common form of backing vocals that are tracked in pop music.
Sometimes when these parallel vocals are tracked the S’s don’t line up well with the lead S’s, or, when they do line up they can be too loud due to the accumulation of multiple S’s. One way to combat this is to strongly De-Ess the backing vocals so, on their own, they do sound as though they have a lisp. However, when they get integrated into the mix, the lead vocal will fill in the spot where the S’s used to be in the backing vocals and they won’t sound like they have a lisp anymore. The backing vocals will fit into the mix better and there won’t be over ess-ing that occurs, or, misalignment of S’s.
Another good practice is to compress the backing vocals a little more than the lead so that you can have them sitting at a lower volume but still be able to hear them clearly. Also, if you want to increase the degree at which they sit behind the lead vocal you can increase the level of the reverb on the backing vocals. This will certainly place them behind the lead.
As stated earlier, this is not a rule when recording backing vocals, but it is a good trick that works very well in making the backing vocals, or BV’s, sit in the mix without sounding messy and out of control. “