Setting up for live sound (Unit 23)

Setting up small PA system we identified the key elements of the process. This post gives a short explanation of each element and how we set it up.  

Power

As the mixing desk, FOH speakers, monitors and amps all need power knowing how much power you need and how you'll get it to the stage is important. Putting everything in place and ensuring everything had power first meant we could build around them and not have to move things about to much later on.

• Using extension reels we set up 4 power points on the stage, one in each corner.

Mixing Desk/multicore

Having the mulitcore positioned stage left and its single cable running to the desk made setting up the stage much easier later when we started miking instruments. All the in/output to the multicore are XLR and the desk has XLR & 1/4" jack outputs so we have XLR to1/4" converters where appropriate. 

• We connected the XLR outputs of the core to the corresponding XLR inputs of the desk up to 16 (the max inputs on the desk).
• Getting sound from the desk to FOH we used 2 of the 4 returns of the core (A for L & B for R) to take the L & R signal from the main outputs of the desk to the multicore.
• In preparation for the monitors we set up 4 aux returns from the desk to the multicore through the C & D return cables and two of the inputs by using XLR gender changers to turn them into returns.

We learnt that working in a logic method helps later when engineering. Eg having the extra aux returns descending from the highest cable on the multicore instead of any free cable. This helps the sound engineer work efficiently and removes any confusion as to where sound is being sent and received from.

FOH Speakers

These are the speakers that the audience hear sound through. Having a FOH system that can amplify sound at a level appropriate for the space easily is important. The FOH speakers we used had a sub speaker + a mid and treble speaker. This system allows you to input the signal to the sub and create a crossover. allowing you to output the full range of the signal or the signal with a high pass filter on.

• Using XLRs we connected the A & B outputs of the multicore to the left sub and the right sub.
• Then with XLRs we connected the highpass output of the subs the input of the mid/treb speakers.
• As FOH speakers have volume controls on them we had to set the left and right to the same level.

Monitors

These are onstage speakers that the musicians can hear themselves through to help stay in time. If a production is big enough there will usually be a separate mixer & engineer at the side of the stage to control them. We intended to have 4 monitors all with individual mixes allowing us to give a each musician or groups of musicals individual monitor mixes. 

• We plugged the 4 monitors into the multicore outputs that we had set up for aux sends earlier.
• We set them up in the appropriate place so that the musicians would be able to hear them and taking into account the position musicians naturally get into when playing. 
• We also had to set them up in a way to prevent feedback to nearby mics by finding weak spots in their polar pattern and placing them there.

As with setting up the desk & multicore doing things in a logical order helps later on. Eg having the monitor closest to the front and stage left linked to the first aux channel and ascending around the stage anti clockwise. We also learnt to check the monitors are receiving sound and the auxes are working before sound checking for the FOH mix. This way when musicians ask for more/less of something in they're mix we can adjust it knowing it working without hearing it. 

Miking

We mic the instruments/vocals on stage so that we can amplify their sound through the FOH speakers. As you do this its important to keep it as tidy/presentable as possible. Clip on mics and kick drum mic stands can aid you with this. We had a drum kit, bass, guitar and vocal on stage.

• We miked & DIed instruments and amps.
• We plugged the mic cables into the appropriate inputs on the multicore to send sound to the desk.
• We ran cables around the stage rather than across it to avoid trip hazards.
• Tape down any that have to across the stage.

We learnt that if you find mic cables are broken when you sound check its more time efficient to just unplug the broken one, leave it in place and run the new cable over the top.