How to add sub to 2006 A4 Avant ?

[Muziqman]

Hey guys, I just got a 2006 A4 Avant and I'm wondering what it would take to add my JL Audio JX500/1 Amp and 10" JL Sub to the stock non-Bose system. This amp and sub was in the trunk of my previous car and it's only 1 1/2 yrs old and sounds awesome. I assume I will have to run power from the Battery by going thru the firewall etc as you normally would, but what about signal input? Does the stock amp in the back have a sub out terminal or would I have bypass it all together? I'm also looking at installing a Pioneer Head Unit down the road as well to get Bluetooth and aux inputs, will this change or affect the sub install ?

[naiku]

Before ditching everything in my 2006 Avant I spliced RCA's onto the outputs coming from the OEM head unit. It sends out a low level signal, tap into that before the amp and send the signal to the JL. Without knowing exactly which amp you have it will be tough to say which wires to splice into, but if you search here and in the B7 forum you should find all the information you need.