Power strip, speaker freakout

[quantum112]

Hey folks. I have a question that's more in the electrical domain, but since it concerns speakers, I'll put it here. I have these 8" studio monitor speakers that have always popped a bit when turning on - they've been working fine for a year and from what I read on certain models this is normal. However, the left one popped a lot louder in the past few months and I couldn't really trace it back to anything specific.

The other day I turned on my CRT and noticed some kind of vertical bars of alternating brightness scrolling up the screen and from what I read this was indicative of a ground loop - that's when I began to question my wiring.

I have two power strips that all my PC stuff is connected to, each in its own wall socket. One of them is a classic power strip, and the white one has an on-off button that lights up when it's plugged in and "on", looks almost exactly like this.

The classic one had only my PC plugged in and the switch one had the speakers, display etc., and stuff worked except for the excessive popping. So I thought I'd switch the strips so that the left speaker was the only thing plugged into the switch-strip and everything else in the classic, and when I turned on the left speaker... HOLYF***TURNTHATOFFRIGHTNOW. Some kind of loud drilling noise, is the best way I can describe it. Distortion of some kind. This wasn't any kind of normal interference which is relatively quiet, this was jackhammer level (they are 140W).

My only guess is that the switch on this white strip is causing some kind of breaking up, almost as if turning on and off 100 times a second, causing the amp to freak out. This is a really cheap power-strip from a generic store, all the other ones (without switches) that I've bought there work fine.

I got rid of the switch-strip and plugged everything into classic strips and the popping is a lot quieter. The speaker, luckily, doesn't seem to have taken any damage. What I'd like to know:

1) Technical explanation of what the hell happened there?
2) How come, plugged into another wall socket and with more load on it (monitor, lamp, printer, etc.) the switch-strip didn't cause any crazy stuff to happen with the speaker (except the loud pop @ power on)?
3) Is it possible for something like this to affect and actually damage other devices like displays, PSU's, etc.?

Thanks

 

[TESLA]

1) The monitor speakers, really their internal amplifiers, probably have internal fault protection circuity. Sometimes the pop that you hear is not coming from the speaker(s) at all and is really a result of a relay switching itself off.

Sometimes these internal protection circuits can conflict with external protection circuits, or it could have been due to a bad power strip with faulty internal wiring.

Also, it may be that your monitor speakers are best left plugged directly into the wall if they already have fault protection built in.

2) Power strips are only limited by their ratings. You can have a power strip designed to take on a 30 A circuit with capacity to spare. It all depends on what the strip is meant to accomplish. 140 W x 2 is not really a lot of power, and even if you had everything else plugged into it at the same time, you may not have even been close to maxing out the circuit.

If you had a full home theater with seven channels and multiple subs pushing hundreds of Watts each, then I might feel differently, but with your current setup, unless you are tripping a breaker or your power strip is not rated to handle the load (all strips should have a rating in Amps), you should be more than fine. (Depending on where you live, you are probably using 15 or 20 A breakers. If your power strip is rated for the max of your breaker, you are golden, assuming good construction.)

Keep in mind that just because your strips were connected to different wall sockets does not mean that they were connected to different circuit breakers in your box. More likely than not, multiple plugs within the same room will all be wired to each other, so you aren't actually splitting up the load as much as you may believe that you are.

3) Possibly, especially if the strip itself was bad and had an internal short.