Q: I just started helping a loca guy here with PA and I’m finding it kinda fun.
It seems I’m picking up on stuff fairly quick, however, there is one thing I keep messing up on that I’m just too embarrassed to ask.
Every time I power up or down the PA, there’s a funny ‘Kapow!’ sound that the speakers make.
What am I doing wrong? Is there some way to avoid that?
A: I’m glad to hear you’re enjoying your fins time working with audio!
However, my first point would be that you should never be too embarrassed or self-conscious to ask a question. Some information you might receive is critical, if not for your safety then for te safety of the equipment.
So, always ask questions if you’re unsure of something.
As to that “funny kapow sound”…
There is a specific order of powering on and off your system components that you must learn and follow to avoid damage to your loudspeakers and other gear.
Always make sure that your power amps are the last item turned on and the first turned off – every time you use your system!
Many pieces of audio gear emit a power spike, or a transient “thump,” when powered on and off. This uncontrolled signal can damage speakers that aren’t protected against such abuse. Learn to follow this sequence when you power up:
1. Make all mic, mixer, outboard effects, and output cable connections with all devices off.
2. Turn on your outboard effects units (if any) first.
3. Turn on your mixer next.
4. Then turn on any speaker or amplifier DSP units.
5. Finally, turn on your amplifiers or powered speakers.
When powering down, reverse the sequence:
1. Turn off power amplifiers and/or powered speakers.
2. Turn off any speaker or amplifier DSP units.
3. Turn off your mixer
4. Turn off all outboard gear.
5. It’s then finally safe to disconnect your cables.
It’s important to wait a briefly after turning off your power amps to let them discharge then continue to turn off gear in sequence.
Some DSP units even warn in their manual that “It is imperative that the power amps are turned off prior to cycling power this unit.”
To guard against Murphy’s Law – the accidental shutdown of the DSP, your mixer, and outboard gear during a gig, many people find it useful to use an uninterruptible power supply (UPS). We have covered this previously in regards to studio use here.
As always, we welcome input from the PSW community and would love to know your thoughts on this topic. Feel free to let us know in the comments below.
For more tech tips go to Sweetwater.com
