I once attached a subwooker to a pass labs x350 power amp incorrectly. i did not understand the manuals instructions to be honest. pass really should include diagrams and warnings which are clear, not commentary type instructions. the amp died and was given in part exchange for a new amp. a single diagram in the manual as to how to instal a powered subwoofer would have prevented this! the sub woofer also died. the sub was sent back to the manufacturer, mj acoustics. i was quoted for repair and declined, asking them to send back the sub. they became rather unfriendly all of a sudden for reasons i did not understand, threatening legal action, suggesting i will attempt to sell the item on an auction site and there was a safelty issue! this is of course nonsense as hundreds of items are listed as faulty/ repairs required. one call to them from my friend who is a solicitor, resulted in the damaged sub at my door early next morning, and shortly after at the local dumping skip. the experience upset me so much, i did not even want to recover some money. yes, things can go wrong, we are all human, but manufacturers dont always help. like i mentioned earlier, one diagram in the pass instruction manual would have prevented this whole unpleasant experience. however pass want to stay above the crowd with hi end arrogance and think it too low for them to provide a diagram in their manuals. surely, thats only for the likes of budget kit! they are wrong. i really like their kit though, but am very cautious when hooking it up.