Playing Live - How to Mix Your Band's Sound and Deal With Sound Problems
By Jez Rogers
Sound checks are all about getting a band's on-stage sound balance right, but with a crowd in you will need to make some further adjustments as two things will have changed. One, an audience alters the venue's acoustics, and two, the band will be running on adrenalin and likely, despite all the sound-check agreed balances and levels, to be playing louder than usual. The audience absorbs a lot of the sound especially the higher frequencies so you will have a different tonal balance than you did with an empty room.
Vocals are likely to be getting lost in these new dynamics so slowly turn them up a little at the mixing desk and adjust tone controls for more clarity. Slow and gradual adjustments mean the audience won't suffer sudden changes. You can turn the bass player up or down for a better overall balance without disturbing the band on-stage. Although he has The Final Word, the sound engineer should make technical adjustments and not artistic decisions but an inexperienced band will often forget the agreed sound check levels and be far too loud in a panicky response to the audience in front of them. If so, the engineer will need to reset their levels. There are also occasions when the band might need to be louder, too. Again changes need to be gradual - unless there is an obvious glitch such as a gain knob that's been brushed against and has turned itself to 11 or someone who hasn't flicked over a stand-by switch! It happens.
Other than problems like that, the engineer must not meddle with the sound on stage as the band have to be able to hear what they are playing; and unless the sound mix is awfully wrong, adjustments should be made songs so the audience only notices a gradual improvement and not a sudden dramatic change. The middle of a gig is not a good time to be asking band members to adjust their tone and other settings unless they have reneged on the agreements or there is some unexpected factor that is demanding a change (sometimes using back-up instruments or other technical issues can require this). An interval can be a vital chance to get 'under the bonnet' but don't try to re-engineer the gig completely; focus on simple adjustments to cope with unexpected problems. Issues can arise with power amps, with monitors, gear failure (my band's live 'check list' has over 100 items, plenty of scope for glitches).
Here are ways to approach the most common problems that arise during a gig:
Dealing with Feedback
I'm not referring here to the deliberate generation of individual instrument feedback by a guitarist, but when, at a whole band level, the volume rises, and the sound from the speakers reaches microphones, it is then amplified and goes round again, is literally "fed back", and then gets amplified again becoming a painful howl. This is the feedback issue that you need to avoid, prevention is far better than having to cure it! A first line of preventive defense is to use decent vocal mics (such as Shure SM58s). Have the mics well behind the PA speakers, which must not be pointed at the mics. Make sure the singer doesn't cover the rear mesh with their hand and get them as close to the mic as possible. Watch out for singers who start roaming the whole band area or charging forwards of the speakers.Pointing the rear of the vocal mic at the monitors helps as they are designed to be less sensitive in a direct line in this direction. Turn down volume controls one at a time to find out where the feedback is starting.Tweaking the tone controls may help.Try moving the mics to avoid any stubborn resonant areas.When all else fails,turn the volume down. Oddly, it's often not the main issue.
When its all a Bit of a Mush...
There's no real heading for this but you'll soon know when it all sounds a bit squashed and foggy. There are a couple of reasons that are most likely to be at the root of this. A high level of sound on stage: When onstage levels are high, the vocal mics will be picking up the instrument amps. If the onstage sound level exceeds 90dB, and it usually will, then some of that sound is going to be louder than the singer.Listen to the PA when the vocalist isn't singing and you can hear the sound that shouldn't be there.This turns your sound to mud and gets worse due to the slight time delay involved. Moving the back-line so it doesn't point directly at any vocal microphones will help. As with the feedback issue, good vocal mics also make a world of difference, not picking up that stray sound to the same extent as cheaper, inferior types. It doesn't pay to economise on vocal mics.
The issue of tone:
The aim is to separate the band's instruments in tone. Guitars with too much middle will fight with the vocals; and, if guitarists have their bass setting high, especially with an open backed cab, and the bass player has his lower mid range well up, this heavy energy will dominate the stage, especially if there is keyboards with lots of full left hand chords! This could be an artistic decision if you want to be exceptionally heavy, but experiment with all the options available to you and try for an optimised setting with light as well as shade if you want a cleaner sound. A fully mixed system gives you the option of separating all the instruments in space by using the pan controls. Ideally, this is one for the engineer to rehearse with the band or sound checks could take hours.
About the Author
Jez Rogers is a guitarist/singer performing both solo and with several groups. His Sea Company project promotes local music with training and advice on setting up bands sound systems for live performance. Jez writes from hard earned experience, his newsletter for news, reviews, guitar tuition and advice on equipment for live performance and home recording is available free at http://sea-company.heart-shapedworld.com/
(c) Jez Rogers 2009