I have a Kicker Cvr 12" 4 ohm, wired to a kenwood 600 watt amp but ever since I've had the sub I've tried wiring it down to a 2 ohm load, every time I try to, it begins to do a "heart beat" distortion and end up wiring it back in a series, 8 ohm load. This sub was brand new and is only 2-3...