I have a 92 sc 400 and i blew out my sub this week. I don't have a lot of cash and the Lexus dealer wants to charge me $500 to replace it. Is there any way i can replace the sub with different brand without getting a new amplifier with it being the same way? Should i get a new sub and amp?...if so what do u reccomend that will fit into the current space for the sub. thanks please help