I have different sound systems here. Some of them share the "problem" that they make a "popp" sound when I switch them on or off using the front-panel switch. If I accidentally switch off the socket they are plugged in, it's a very loud "popp" or more a "bang".

I know that some audio systems implement a soft-start circuit to overcome that problem. I can hear some relays click a few seconds after I switch the amplifier on, and from that moment on I can hear the music.

My questions:

1) Does that normal popp after front-panel switching harm the loudspeaker?

2) Does an accidental power-off, which causes that "bang", harm the loudspeaker or some circuits?

3) How should one implement a protective circuit? Is it sufficient to set up a delay-circuit which controls some relays on the output of the amplifier circuit, or is it better to do it in "stages", e.g. first let the supply start, then give power to the amp and in the end switch on the loudspeaker itself?

Best wishes and thanks for your time in advance.

  • \$\begingroup\$ The best thing to do would be to turn the volume to zero then plug in the cable \$\endgroup\$ – Voltage Spike Aug 20 '18 at 22:22

These question may be better suited to the Sound Design Stack Exchange and should probably be broken into two separate questions; but here's my take.

  1. In short, yes the pop or bang you hear can damage loudspeaker, especially high frequency drivers that are usually rated at a lower wattage handling capacity.

  2. It is not the power being suddenly turned off, but the instantaneous surge that is supplied to the loudspeaker drivers that can be damaging.

  3. While you could relay the speaker cables to disconnect them, typically professional sound systems use a sequencer to power on the amplifiers last after the front end equipment is powered on and turn them off first to avoid these pops produced when the front end equipment is shut down. There are commercially available power sequencing systems from Furman, Tripp Lite, SurgeX, Lowell or other companies you should be able to search for.

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  • \$\begingroup\$ Hi CoreyF, thank you for your answer! Yes, I will definitely split up questions in the future ;) -> Hence I will create another question here on the "why" of that "popp" on circuit-level... I think on the circuit level I have to create it in the EE part rather then in the Sound Design part (because I assume that these surges are common for many amplifier circuits, not only for low-frequency-(audio)-circuits, right?)? A question to your third answer: Does "front end" here refer to the mixing console for example? Thank you a lot for your time!! \$\endgroup\$ – Justin Time Aug 15 '18 at 7:54
  • \$\begingroup\$ To interconnect the articles, here is my circuit-level question: link \$\endgroup\$ – Justin Time Aug 15 '18 at 9:06
  • \$\begingroup\$ By "front end" i am referring to everything in the signal path ahead of the amplifiers which include the mixing console, equalizers, cd/mp3 players, computers, active crossovers, feedback eliminators, digital signal processors, wireless microphone receivers, etc. \$\endgroup\$ – CoreyF Aug 15 '18 at 15:33
  • \$\begingroup\$ Ah perfect, thank you :) I just wanted to make sure, that I've got it right ;) I will mark your answer as the solution. Thank you !! \$\endgroup\$ – Justin Time Aug 15 '18 at 15:46

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