KRK 10s sub cutting out at a certain volume

[seamus]

My KRK 10s subwoofer has a problem where at a certain volume/power draw it will make a small pop and cutout completely. Once the volume lowers down the speaker will com back and continue to work as usual as long as it's below the volume it cuts out at. This will consistently happen at (I think) the same power draw/volume and will not go louder than the cutout point. The only issue I can find by visual/audible inspection is that the relay on the amplifier board is making an arcing noise when the speaker is first turned, and makes the same noise whenever the speaker cuts and comes back. From research this relay is working with a delay circuit to protect the speaker from power surges when plugging in/turning on pops. I was just looking on some guidance on where to look to solve an issue like this? I have check connections and grounds and cannot find any visually obviously blown components.

 

[Diver300]

I would check the electrolytic capacitors. They degrade with age. If the capacitors aren't working properly, there will be more ripple on the dc power supply, which will be worse at higher volumes. The ripple may be being seen as supply voltage dropping by the protection circuitry.

 

[Sophia Zeng]

1. check if it is because the capacity of the power supply decreases; 2.If the power amplifier is poor performance?