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19 Feb 2018

PA System Preflight Checklist

History

PA System Preflight Checklist

In 1993 Juliusmedia ran Certificate III courses in Sound and Lighting. The following article appeared in the first edition of CX Magazine in March that year.

Pilots use checklists all the time – and live audio has some similarities to flying!

This checklist is what our students use to get a system ready for the mix. There’s always a few things that can be substituted and a few things that can be left out. The fundamentals are to be ahead of the situation, so becoming thorough in your methodology is the best way to start.

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Too many times we hear of frantic searching for faults when the cause ends up a device not turned on. So check all those power on LEDs are glowing, everywhere! A note about ‘Room Trip Point’. There are three maximum level conditions we search for when doing a system check. One is amp clipping, we run under that level. Two is where the room acoustic ‘collapses’. We call it the ‘trip point’. Three is the point of feedback. We run under that level too.

PA System Preflight Checklist (1993) 

 

Before power up
> Amps turned down
> Desk faders turned down
> All mains connected
> All speakers connected
> All powered speakers ‘off
> Adequate power – check
> Location circuit breakers – check
> All speakers secured
> Worklights in place
> All leads secured

Before system check
> Desk EQs all flat
> Desk Auxiliary sends all off
> Input gains and pads uniform
> Phantom power off
> PFL off
> All mutes UN-muted
> Desk faders down
> System equalisers flat
> System equaliser gain at unity
> System comp/limiters at unity
> System comp/limiter ratio 4:1 or 3:1
> System comp/limiter threshold out
> All devices powered – check
> All amps powered – check

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Before Sound check
> All personnel advised of loud sounds
> Affected personnel vacate room
> Low level signal run through system
> Signal present at all amps
> All speakers working normaLy
> Your reference CD run up
> System run up to amp limits
> All speakers working to limits
> Comp/Limiter threshold under limits
> Desk output gain noted at limits
> Room ‘trip point’ noted
> CD turned off

System Sound Check
> PA ‘tuned’ using vocal mic at desk
> PA ‘tuned’ to open stage mies
> Monitors ‘tuned’ to mic on stand
> Monitor feedback point noted
> Monitcrs set 2dB under feedback
> All inputs connected, noted
> Line check each input at FOH
> Line check each input at Monitors
> Set each input gain using PFL meter
> Set EQ on each input
> Set desired levels
> Note maximum levels before feedback

This item first appeared in the print edition of CX Magazine March 1993, p.69. CX Magazine is Australia and New Zealand’s only publication dedicated to entertainment technology news and issues. Read all editions for free or search our archive www.cxnetwork.com.au

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