i believe the monsoon sytem is crossed over in side the system so that when you try to replace the factory amp using a traditional high low adaptor you will lose a but load of frequencies, I am actually getting ready to do this in a Trans Am with a Monsoon system and I found out that Peripheral designed a new 8 channel line output convertor specifically because of this issue it is called the Peripheral PCH8, sorry but I do not have pricing on the unit yet