When you say it is shutting off or muting the rest of your system, to me, this is a sign that there is a short. I was recently installing in wall speakers in my Theatre room and the insulation had a foil backing. Everytime I hooked up my front left speaker, my surround system (receiver) would shut off. The foil on the back of the insulation was creating the short as the speaker rear and connectors were pushing against this foil. Sounds like a similar problem may be happending with your sub's input (based on your statement that you think you may have done this). First, I would check the cable to make sure that is not the problem (try a different cable). Secondly, I would pull the cover or plate that may allow you to see the other side of the binding posts/connector on the sub (from the inside, not the side where you plug your cable in when hooking up). Look for a loose strand, something bent, something moved and now you have metal touching metal.
It could be, as you seem to have expressed concern, that it is the amp in the sub, since you don't seem to feel it is very well made. I know nothing about this amp.
It could be, as you seem to have expressed concern, that it is the amp in the sub, since you don't seem to feel it is very well made. I know nothing about this amp.