I ran a 10" sub and amp off my factory delta head unit no problem. I spliced into the low level outputs (rca) of the headunit.

 

Naw my box is in my trunk. Its really big and i would rather of had a small one because i play golf and when i have to put a couple bags in the car im screwed. I wired hot connect ports to the box so i can quickly disconnect the box. It worked really well.

 

Adding subs to an otherwise stock system can be done, but why would you want to? An upgraded headunit or speakers will yield better results than simply gettin SuBbZz. Better to go about it the right way, then add subs later.

Steve

 

It is possible to run the subs off a stock deck as some people mentioned above, but you will only get 1/2 a volt to the amp which is just crap. Since that signal is going to the subs, you won't notice how bad it is because your only getting low tones (But you will get sloppy bass). If you go ahead and do this tap the rear speakers right at the radio instead of the amp so you get a slightly better signal.

 

is that true? cause, i was thinking of adding a sub because i would like to keep the stock look....but knowing that, i might just want to get a new deck and use that power for the bose system.....if i got the new deck hooked up to the bose system....would it make that bass any more or what would the difference be do you think???

 

EDIT: I misread what you typed, my bad...I mistakenly thought I read "tap the rear speakers" and didn't see "right at the radio". I edited my statement to reflect that

Most importantly you're going to pick up more road noise through high-level signal in non-protected speaker wire as it travels to the rear speaker than if you tapped behind the head unit. When you convert at the head unit you'll be running a low-level signal through shielded and twisted RCAs (hopefully, as long as you don't buy cheap WalMart crap) and you'll prevent a lot of the road noise you'd otherwise pick up. I've seen plenty of installs where the subs sound like crap because they are tapped at the rear speakers that have been fixed by running a line level converter at the head unit.

 

ive been in cars with 10,000 worth in sound systems and my subs and amp on the stock system sounds soo much less than that does. I mean spending 10g in sound system sounds amazing. as i said before- you get what you pay for.. but as for more BASS just for BASS then running off your stock headunit .. you wont hear that much road noise.. expecially in mine.. i spent a lot of money on high proformance RCA's and they sound great.

 

so if i were to tap the line out converter right behind the headunit....and get some nice rca's then i should be golden...right??? and if so....where can i get the tool to take the headunit out....btw i have the bose audio system in an 03 a4 18tq.....everything that i have read has been very unclear....does it already have rca outputs on the back? or what about doing like what jestnoman did and splice the rca's before the bose amp....?????let me know the best way to wire an amp to the stock bose headunit would be....

 

Well this is where things start to get sketchy for me. The tools I believe you can buy at a Pep Boys or something like that, also I know Crutchfield.com sells them as well. The part I'm sketchy on is where to tap into the Bose system at...I've seen some cars where the signal leaving the radio is a low level signal to the Bose amp where it is converted to a high level signal, in which case you need to tap in AFTER the Bose amp. But then other cars are high level signals into the Bose amps, in which case you tap in behind the radio. So on an '03 A4, I'm not 100% sure where to tap at.

 

is there a way to check if the low level is from the deck to the amp or whatever? I'd like to install my sub sometime soon....