Saturday, February 5, 2011

Its all about the vocals...

Lets be real. The hardest part of live sound is the vocals. Sure, drums can be tricky and so can acoustic pianos. Really any instrument could decide to be difficult for a day but vocals are a consistent challenge. Maybe the difficulty arrises from the fact that the human voice is infinitely more complex than a kick drum. (I know we are all chasing that perfect kick drum tone, but be honest.)

In church sound, vocals become even more important because the message that is being communicated is entirely in what is being said or sung. If the vocals are bad or unintelligible, we are not doing our job as audio engineers in a church setting. Here's my process for taking on this challenge.

Choosing the right mic is important. The classic SM58 can be made to work for many situations, but there are many excellent options out there, so don't limit yourself to your trusty 58 (or whatever mic you might like). I prefer super cardioids for most situations, as they help tame the proximity effect found with cardioids. Hyper cardioids tend to be too precise in their off axis rejection for all but the most experienced vocalists, so super cardioid it is, mostly. Proximity effect may be just what you need to warm a vocal or extreme off axis rejection may help you with your stage volume. The point is, try different things. Personally, I have far fewer mic options available in my stash than I would like, but that is something that I'm working on. Condenser vs. dynamic will also be a question for you to wrestle with. Here is my rule of thumb on the matter: Condensers are usually more transparent, so if you have a great singer, the condenser will let them shine. But if you have a no-so-great or average singer, the condenser will just reveal their imperfections more clearly. So, as always, use your ears.

Remember the high pass filter. It is your friend, especially with cardioid mics suffering from the proximity effect. Don't be afraid to high pass pretty aggressively on vocals. Some voices can be high passed as high as 130Hz. Sometimes I'll high pass up to 120Hz and then use a low frequency shelf to knock down 120Hz to about 400Hz down a few dB as well.  This really gets rid of mud, plosives etc. I never mix vocals without the high pass engaged.

When using EQ on a vocal, try to stick to subtractive EQ. It sounds more natural and is usually all you need. The 200-400 Hz range and the 800-1000Hz range are common problem areas. The nasal quality of the voice is in the 800-1000Hz range. Boosting gently from 2k-5kHz can add presence and clarity but, again, use your ears because this can also sound too harsh. I generally find myself making a few precise cuts and few if any boosts.

Related to EQ is De-Essing. The harsh sibilance or "S" sound in vocals in usually around 7kHz. I really hate cutting that band out with EQ because if also takes out some clarity. You may be in a different situation, but the PA that I am working with tends to get rather harsh in the upper mid-range, only making the sibilance problem worse, sometimes painful. So for me, de-essers are a lifesaver. I use them on all vocals and they really clean up the upper mids by suppressing that sibilance before it gets out of hand. You may not have such a serious problem with sibilance in your situation, but its something to be mindful of.

Next up, compression. The key here is DON'T OVER DO IT! Compression can be great but it can also kill your vocals. I once checked in on a volunteer who was complaining that he couldn't get the vocals where he wanted them in the mix. A quick survey of the signal chain revealed the problem. He was catching the vocals at -30dB and compressing them 4:1. Talk about taking the life out a performance. A quick explanation and a few adjustments got the vocals back to where they needed to be. So be cautious with compressors. With the advent of digital consoles and compressors for every channel, its might seem like a good idea to compress most everything. Its not, so don't. If a vocalist's singing volume wanders a bit, some compression will even the level out. Bussing choir mics to a group and compressing the group can unify their sound. But compression will not make a bad vocalist or a poor mic selection sound good. And more compression definitely does not equal better sound. Be discerning. Better to use no compression and ride the fader than use compression poorly.

I don't find myself needing vocal expander/gates much currently. However, there was a time when I mixed and muli-tracked in a venue with a lot of stage volume and gates helped eliminate some bleed into the vocal mics. Gates are also great for minimizing feedback when using a lot of open wedges. They'll save your life when that new singer inadvertently point the mic straight at the monitor.

Reverb can muddy a mix as quickly as it can open it up. If the song is fast paced with lots of instrumentation, very little reverb is needed. In fact, using a lot of reverb will just bury the vocal in the rest of the band and smear the clarity. Slower, simpler, more open arrangements are when reverb is really useful. It can take a powerful vocal performance and make it simply HUGE! But as with any effect, its easy to over do so just be tasteful. I like the ReVibe on my Venue but there are lots of good reverbs out there. Avoid harsh sounding cheap units.

With digital effects and consoles, there are a million reverbs available at one time to an engineer. Please resist the temptation to use a different reverb on every channel. The whole point of reverb is to place the performance in a specific acoustic space, not to place the drummer in a bathroom, the acoustic in a cathedral, and the vocals in the Grand Canyon.  Its important to be somewhat consistent in the feel or spaciousness of the reverbs used together within a song.

Personally I love the Echofarm plug in for the Venue. Its easy to use and has some great sounding delays. But be aware: delay is even easier to over use than reverb so be even more careful. Delay is one of those effect that you save for specific points in the performance. A good delay can do wonders for a song but you don't want to give away all your tricks up front or use them so much that they lose their effect. And please make sure your delay is timed properly for the tempo of the song. Please.

Well, thats about it. Its good for me to actually write out the process. To sum up, the two biggest keys to a good vocal mix is mic selection and EQ. You should be able to make it work with just those two. All the rest is just nifty icing on the cake and won't fix any problems that are left after the mic and the EQ. Vocal EQ is also one of the hardest things to get right so we sound engineers have our work cut out for us. Good vocal EQ comes with practice, study, and a lot of trial and error.

No comments:

Post a Comment