Audio Systems: 99 cadillac seville bose sound system, cadillac seville, rca jacks

Question
I am having problems setting up an after market sub to my Bose sound system. I am wondering if you could tell me the do's and don'ts with the bose sound systems to maybe enlighten me to a solution. Everyone I have talked to is perplexed and the dealerships audio techs want me to bring it in instead of telling me it is impossible or this is what you need to accomplish this task.  I have a rca out-put converter and everything is hooked up correctly(in theory) but I have heard myths about bose signals and bose frequency being impossible to tap into.  I don't have money to spend thousands of dollars at car toys or places like that to re-wire my car. Please Help

Answer
you can do that,yes it is possible you just need a good hi low interface for bose system

it looks like this but there are rca jacks in the other end

check here or with pie.net

http://www.oemautosound.com/pc-598-240-oem-interface-differential-converters-uni...