I bought this at a bundle with a 350w Kenwood amp from sonicelectronix. when i first put them in it hit pretty hard and put out some good clean bass but after only a month of bumpin around it started to have this ugly crackling sound at higher frequencies... wont be getting another one of these. maybe i just pushed it too hard being that it is only a 400 watt sub, even though it was only getting 150w RMS. Ehh.