it seems like there is an infinate amount of choices in speakers and amps and head units. i figure this technology has been around long enough that the chinese economy must have replicated the latest and greatest and must have done this for several generations of amps? makes sense right? seems i can buy a 2600 watt "clif design" amp for 100$ from ebay or xs cargo. why wouldnt i run out and buy this to drive my subs? do they make scratchy sounds? do the have a short life? do they utilize voltage differently? do they make noise when you start or shut off your car?