Optimum protection (sound, power surges) for a small PA system


I work at a small events venue in Beijing, China, where I organise live concerts for audiences of 20 to 60 people generally. The music itself runs the gamut from quiet singing to small band performances, with a special focus on improvised experimental stuff which can get very loud.

We've been open for about a year or so, and have had to repair our speakers several times already -- each repair taking weeks, since we bought good equipment (ie not Chinese knock-off brands) that has to be shipped outside of the country to be repaired under warranty. Upon every repair, we were never told whether the cause of damage came from power surges or loud audio signals.

The problem is, neither me nor my colleagues are very knowledgeable on audio engineering matters -- and the level of professional knowledge among sound engineers in Beijing seems to be spectacularly low. In order for those issues to stop, I want to thoroughly investigate the best way to protect our system once and for all!

Here's a quick overview of our simple PA system:

  • 1x 12-channel Mackie ProFX12 mixer
  • 2x Mackie Thump12 powered loudspeakers (12-inch, 1000W)
  • 1x Mackie SRM1801 powered subwoofer (18-inch, 1000W)
  • 2x KRK VXT8 Active Studio Monitor powered loudspeakers (8-inch, 180W) (obviously, we tend to only use the latter for quiet, non-instrumental events)

1/Power surges - As of now, we're only using simple power strips with fuses against power surges. Should we invest in heavy-duty component-style surge protectors?

(recently, as we were setting up for a show, someone tripped over a power strip into which our subwoofer was plugged in. There was a loud "bang" and the sub just stopped working and had to be repaired... Interestingly, no other equipment was damaged.)

2/Sound levels - We've been consistently using the compressors/limitors embedded in our speakers, hoping it would help us make sure they don't get damaged. But it seems this might not have been enough. Should we buy a compressor to better control the sound levels going through our PA system? If so, what kind of equipment would make a reasonable purchase, considering our needs?

Any advice would be highly appreciated!


Posted 2015-08-15T16:23:54.890

Reputation: 21

1Can you add some details about the failures, such as what part of the speakers started to fail (bass/treble/amp), what kind of performances that lead to the failure and if the failure were related to general power issues (power outages, dimmed/shivering lights, pops etc). Thing is that with active speakers and in particular those models, you're already well protected against overloading the speakers because the amps and speaker ratings are matched and the amps contain build limiters.. – Michael Hansen Buur – 2015-08-16T19:32:45.310

Sorry Michael, I saw your question a tad late. Our speakers have known different issues, sometimes the treble failed, sometimes the bass... In general we tend to hold rather "experimental" concerts, in which performers play around with a whole gamut of very high- or low-pitched sounds -- but the performances themselves only last about an hour or so, and don't involve very high sound levels. As for power issues, we don't notice many on a regular basis, but the Beijing electrical system is notoriously "dirty"... Thus my concern. So should we invest only in better surge protectors? – killer_rabbit – 2015-09-05T13:35:57.110

No answers