I don't think it's a solder connection. I messed with it a bit more this evening. I took a device home from work that audibly measures noise in the AC lines. When I plug that device into most of the outlets in my house it is silent. However, when I plug it into the outlet where the sub is plugged in it is very loud even when the sub is turned off.
This video may still be processing on Youtube so it may look like crap.
I don't have a scope and I doubt I could bring one home from work. What I find to be really interesting and baffling is the fact that this problem only crops up when playing audio from my PC. As you can see in the video, the audio drops out for a split second when I plug the sub power in (with the sub turned off) when playing audio from the PC. It does NOT drop out when playing audio from the Dish DVR.
I think we might be getting closer to the fault.
I can tell your sub amp has a miserable
computer type switching power supply, which most do.
As you will see there is no power transformer.
The significance of all this is that the load it takes from the house AC power supply is highly discontinuous. The result is loads to neutral that house wiring was never designed for and generally still isn't. Some jurisdictions are now starting to change new building electrical codes because of this problem.
The other thing you will see, is that the input stage of those power supplies is always active whether turned on or not, which is why you get the buzz when you plug it in.
What I can tell is that the circuit your sub is plugged into has severe neutral gouging. This may have come about, by your sub chronically overloading your neutral, and you may have a hazardous situation developing.
I can not exclude the possibility your sub power supply and causing neutral gouging above and beyond its design criteria. These power supplies are notoriously fault prone as sub power supplies. Horror stories abound!
Your computer also has one of these power supplies, they all do.
So I think your sub and computer power supplies are interacting because of a neutral gouging problem. So it is your computer that is interrupting the bit stream, when your sub really puts the hash down the neutral line.
So job one for you is to have that neutral line checked.
Unfortunately electrical codes have allowed neutrals to be shared between multiple circuits! This was done on the assumption that neutrals carried little current. This used to be so, but not in the modern home.
However with the introduction of these power supplies, especially devices like your sub, neutrals can become overloaded. This results in heat build up at splices and terminations, with further deterioration of neutral capacity.
I hardly need to point out that neutral overload does not trip breakers, just burns your house down. I have been called out by local artisans puzzled by alarming situations on neutral terminations, and even a case of repeated blow out of a pole transformer due to neutral gouging. I think I have the local artisans alert to the problem now, including the local electrical inspector.
So these are Carter's rules for staying out of trouble from this problem with your audio equipment in house that has standard house wiring practice.
Don't use subs with plate amps. Use amps with traditional power supplies in their amps.
Isolate computers from your system, and always use an external sound processor, never one powered from a computer power supply. The sound processor should have its own power supply with a mains transformer.
