Mixing vocals is an art.
It's tough to get them right, especially hearing the lead vocal throughout the entire song without things getting to loud.
To help you navigate the troubled waters, here is a short guide for mixing vocals.
Good sound starts with gain. Yet, most church sound techs are not quite sure how gain is different from adjusting the volume. If you do not quite understand gain, be sure to check out my post, How to Set the Gain on Your Mixer. You will discover the true purpose of gain along with a step-by-step guide for getting it set right each time.
If a vocalist is singing into a mic like they should (distance of an inch or less from microphone to mouth), you will get a nice, full sound. However, if you leave the EQ as is, there will be way too much low frequency noise, which makes it sound muddy and also gets in the way of instruments that belong in that space.
To fix this problem you should first activate the low cut filter (aka 'high pass filter') on every vocal. This gets rid of low frequency pops and unwanted breathing noise by cutting low frequencies that shouldn't be reproduced on a vocal anyways.
On an analog mixer, the high pass filter button is usually located by the gain knob and looks like /100. On a digital mixer (like the Behringer X32), simply activate the low cut filter and set the frequency to around 120Hz.
Although this takes care of most issues, you still may want to clean it up a bit using the low frequency knob if you have an analog mixer, or changing the frequency position of your low cut filter if you have a digital mixer. Simply cut out the lows until you get a nice clean sound that still has plenty of warmth.
It is common for churches to mix all vocals in the foreground and bury all the instrumentalists. But, there is a better way. Your mix should have layers and contrast. On the top layer is your lead vocal followed by the instruments that create energy: bass and drums. Then your lead instrument which changes from song to song. For example, in a song like Wake, synth is the lead instrument. But in a song like Good Good Father, acoustic guitar is the lead instrument.
Then, simply layer in the background vocals and other instruments where they fit best. Keep in mind, you do not have to audibly hear every single instrument and vocal. But, you should notice a change if the channel is muted.
You might also enjoy: How to Make Lead Vocals Sound Amazing
If you do not have compression on vocals, you are in for a bumpy ride! There is simply too much dynamic range in a vocal to let it run free. Compression takes the dynamic range and narrows it down, depending on how much compression is added. Then, you will not have to ride the fader up and down through the whole song as the vocal gets louder and softer.
On the other hand, too much compression can take the life out of a vocal. As a baseline measurement, make sure the vocal isn’t compressed more than 6dB on average. The goal is to narrow the dynamic range, not eliminate it.
To learn more, see: How to Set a Compressor for Vocals
When effects (reverb, delay, etc.) are not used on a vocal, it sounds dry and dead. But, effects can also become a distraction when used too liberally. When in doubt, use a plate reverb to bring life and space to the vocal. Turn it up until you hear it, then bring it down to where it doesn’t stand out.
To help separate a lead vocal from background vocals, try using a plate reverb on the lead and hall reverb on the background vocals. This will put them in two different ‘spaces’ so to speak and add a little interest to the sound.
There really is no set-in-stone way to mix effects, so don’t be afraid to experiment. Different songs will have different applications. For example, there may be a song where you want to hear the trailing delay and another where you want the delay to be buried in the mix. Be creative, but don’t forget to cut the effects if the lead vocal starts talking instead of singing...