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I have a pair of powered studio monitor speakers for my PC. Each speaker has a dedicated on/off power switch on the back. It's inconvenient to reach around behind the speakers to turn them on and off each day, so I have both of them plugged into a power strip, which is then plugged into an on/off switch plug (see second image below) with a button that sits on my desk. This allows me to easily turn both speakers on/off at the same time with the simple click of a button.

Recently, one of my speakers has started crackling and popping occasionally, even with no sound playing. The speakers are over 15 years old and have gotten plenty of use, so it's certainly possible the internal components are just starting to fail, but I'm also wondering if the setup I'm using with the external on/off plug switch is possibly to blame for damaging the speakers.

Is it safe to simply cut the electricity to electronic devices like this, vs. using their dedicated on/off switches? Would it be safer if the on/off plug was plugged into a proper surge protector, instead of just a power strip? I'm planning to replace the speakers soon, but I want to make sure I don't damage the new ones with this same setup.

powered studio monitor speakers

on/off switch plug

Michael
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  • Some audio systems have a method of disconnecting the actual speaker from the aplifier during power up/down, to avoid annoying pops. You might take a peek inside yours to see if there's such a thing. – jonathanjo Jan 02 '23 at 18:07
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    15 years old puts your speakers solidly into "Capacitor Plague" territory, and if solutions below don't improve the crackling you may need to open it up and start replacing caps. https://en.wikipedia.org/wiki/Capacitor_plague – Bryan Jan 02 '23 at 20:03
  • The main reason why it isn't wise to unplug a powered device is because the more current it consumes, the more likely you'll get an arc in the connector. – Lundin Jan 03 '23 at 14:21
  • I nuclear reactor cooling system is an electronic device... I wouldn't cut power to that – ScottishTapWater Jan 03 '23 at 20:54
  • I second Bryan's remark about capacitor replacement. A friend had similar M-Audio powered speakers that were playing up. Inside were a number of severely bulging and leaking capacitors - and those units were only a year or two old at the time. – screwtop Jan 03 '23 at 22:50

4 Answers4

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Here's a rule of thumb: if the power is controlled by a toggle, rocker, or push-on-push-off switch, especially when it's adjacent to the power cord receptacle, it's most likely that switch just cuts off the mains power, so it's generally OK to cut the mains supply externally.

If instead the power is controlled by a small, momentary button, then a microcontroller is likely involved, and there may be a shutdown process that would not be able to run if you cut power externally. A well designed product should recover from this when power is reconnected, but it's not a good idea to rudely cut the power.

With large appliances, motors, heaters and other high current or inductive devices, the rule of thumb must be amended: the external switch should be rated to handle that load.

Finally, the crackling and popping may just be corrosion on the input connector. Spray some contact cleaner in, insert and remove the plug several times. If that doesn't help, it may be an internal component or solder joint, but still possibly repairable. Lacking a schematic, having two identical devices makes troubleshooting easier because you can use the "good" device as a reference for internal voltages and signals.

Mark Leavitt
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    Oh wow, thank you for the recommendation to try using a contact cleaner. For whatever reason, I hadn't come across that suggestion while looking into this crackling/popping issue, but I've done some reading now and that seems like a very smart first step. Thanks! – Michael Jan 02 '23 at 19:14
  • I'm glad it helped. I should have added that the volume control is another suspect, but you'll have to open the speaker to gain access to spray cleaner into it. Good luck! – Mark Leavitt Jan 02 '23 at 19:38
  • Speakers which have been overdriven (played at too loud a volume beyond their design specifications, even momentarily) may develop defects which manifest as cracks and pops under some circumstances. This is a fairly common failure mode. – Some Guy Jan 03 '23 at 08:06
  • Note the shutdown process might still be able (if there's one), design might have planned for that. But it'd be tricky [or close to impossible] for you to determine that, however it could be documented somewhere. – user1532080 Jan 03 '23 at 08:30
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    The rule of thumb is a good one but not 100%. Main examples I can think of are where the power receptacle isn't mains but low voltage, where the decaying voltage from cutting the mains to an external power supply can do bad things. That's especially true if the external PSU provides multiple voltages (like some external versions of normally-internal PC hardware). That's not the case here of course. On the flip side a little front-panel push-button can be a push-on/push-off mains switch. This is quite common on hifi amps. – Chris H Jan 03 '23 at 16:42
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    @ChrisH and fraxinus make good points. Editing answer to take these into account. – Mark Leavitt Jan 03 '23 at 19:20
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You are unlikely to physically damage them. Power cuts happen all the time, and a fragile product would not get good reviews.

However, depending on how 'clever' the manufacturer has tried to make them, you might manage to confuse some software that was expecting an orderly shutdown. What's the worst that could happen? It might lock up some stateful communication protocol that has to reset the hard way, or it might return to a default volume setting? A good product shouldn't do either of these things, but I've seen some weird software make it into the field.

Neil_UK
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Yes. If it weren't, the manufacturer would be burdened with in-warranty repairs of all the product that happened to be on during a failure of the AC power.

Davide Andrea
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It is safe-ish with caveats.

If you happen to have a number of electronic devices, all of them powered by switching-mode power supply units (either internal or external), switching them off at once from a central switch is safe.

On the other hand, equipment with big transformers, running heavy motors and some other induction-based stuff can get really nasty when abruptly switched off. These are sometimes able to send great voltage surges to the devices that happen to be connected together with them at the moment when the whole group gets disconnected from the AC source.

Transformer-based power supplies are rare these days, but the high-end audio equipment is exactly the place to look for iron-core transformers. If tubes (valves, lamps) are involved, one can bet that there is a big fat transformer inside as well. Modern transformer-based devices usually contain some protections, older ones usually do not.

The damage from such a voltage kickback is usually limited to a blown fuse or two, but one could never be sure.

If the group of devices contains a big iron transformer, switch off the transformer-based device first. The rest can be switched off from the central switch.

fraxinus
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