Learning Live Audio
Live audio can be a fickle thing.... So many knobs and adjustments, chances of feedback, cables everywhere.... it can sometime be a nightmare. Here are a few tips to help you sound better, and ease the stress of running your own sound
Step 1. Gain Staging
One of the most critical aspects of live sound is gain staging. It is the first step in building your sound, and if you happen to skip over it, your mix can fall apart.
Most digital and analog mixers have a "gain" knob. This controls the gain for the preamp. This one knob adjusts how much volume you have to work with for that particular instrument. (Vocal, guitar, keyboard, etc.) If this is set too low, you will need to turn it up later down the road, sometimes adding noise, or maxing out faders, and having no headroom. (Headroom is important, you can always turn down when too loud, but if you're maxed out, you can't turn up)
While most digital mixers have easy to find displays to see your level, analog mixers can require some knowledge of key terms.
PFL - Pre Fader Level
This button when engaged, shows you the audio level before "pre" the fader. On most analog mixers, you must "solo" the channel you wish to see the level of. Use this to set the gain of each individual channel before starting to build your mix.
This button "solos" the specific channel so you can see things like volume (gain), listen to eq (equalization), among other things. Usually, solo only sends the signal to the headphones, so it wont effect the main mix. (Check your specific mixer, as some have settings that will change this.)
0DB VU - 0 Decibel VU
Without getting too technical, this indicates the 0 point on a VU style meter. This usually equates to -18 DBfs (Decibel Full Scale). Just know 0 DBfs, or the 0 at the top of your meter = distortion (typically sounds bad). So don't gain stage that high. Shoot for an average (signal jumps around this level, it can be over and under) of -18DBfs or 0DB VU. This can sometimes be marked by a change in color in your meters. (Green to Yellow)
Hopefully your signals now have some headroom, but still have plenty of gain for FOH (Front Of House) and monitor mixes.
Remember the GAIN knob adjusts levels before Aux Sends (monitors) and faders (Front Of House), so if you turn that knob up or down, you are adjusting everything. This can put all mixes out of balance, so always set the GAIN FIRST!
Step 2. EQ (Equalization)
EQ can be a difficult to reign in, but here are some basic tips.
Cut "boom" and "boxy-ness". If you feel the instrument or voice is "muddy" or has no "clarity", cut before you boost. Taking low end out, or lower mid-range (250hz -800hz) can clean up the instrument and reveal clarity in it. Try not to go too heavy handed, but use your ears. If it sounds good, it is good.
We always suggest cutting frequencies before boosting. When you cut eq out, you can reveal what is already there instead of attempting to over accentuate those areas. Boosting can be useful in particular situations, but until you have a firm grasp on what frequencies can help and hurt each instrument, keep it simple and cut!
Step 3. Less Is More
Sometimes being a glutton with sound hurts instead of helps. What do I mean?
Just because the instrument is there, it might need extra amplification. Let's take drums for example...
If you are on a small stage where the vocalists are close to the drum kit, or you are in a smaller covered environment, you will most likely not need mics on the drumkit. Perhaps a kick mic to add punch (who doesn't like a good thumping kick?!) but skip the overheads and snare. The vocal mics will all be picking up the sound as well, so there is no need for extra amplification.
Also think about your electric guitar. Is it pointed out to the crowd? are the speakers aimed at your ears? if the speakers are pointed out at the crowd, they are hearing your guitar 2x louder than you are! Point your amp up at yourself, so you can hear how loud you really are. Or, if you really must have that "cranked" sound, point your amp backwards, (if the rear of the stage is open) and mic it for out front. Nothing worse than a guitar that is louder than everything else on stage.
Also consider where you place a bass cab. If you stand right in front of it, you are not getting the full waveform and sound. (Bass is a low instrument, you need to get away from it to allow the waveform and sound to develop)
And last but not least, gauge the crowd and venue. If it is more intimate, down rip their faces off with volume. Its ok to play quieter, but with intention!
I hope some of this helps you get better sound at your next gig. And as always, questions are welcome. Contact us anytime!