Hi Lewis. I have already fitted a sub into my car, but used the high level outputs for the feed. I also only have the 2 channel out on my radio, but this works ok. I don't know whether it's because I only have 2 speakers in my Up!, but it just doesn't sound as good as it did in my Yaris which had 6 speakers. I think that the factory fit door speakers are a bit naff though to be honest.
Anyway, I've had a quick look for you and found something that might fit the bill. In fact I think I'll order one myself. It's only £6.45 on fleabay, so it's cheap enough if it doesn't work. Also you can adjust the output volume to compensate for the RCA output. Have a look and see what you think.
She's all wired in and is working fine. Was a bit worried about the quality as it was from a standard head unit but it sounds crisp. Now time to do my boot build and replace my Fender sub for my Exile . Cheers guys!
Didn't wanna loose maps+more... I got an Exile 12" and a JL 500watt monoblock amplifier. Sounds better then my mates 2 15's in his silly-Civic!
Took alot of mucking around with the amp, everything's turned down on my head unit itself so it's so crisp through the speakers and the bass just coming through the sub. Need more sound deadening though "/.
I changed everything in mine the poor little thing rattles like **** I got 4x 200w alpine speakers and an alpine HU got a crappy halfords sub and amp combination thing atm due to my other amp breaking but looking at getting a new amp and 2x subwoofers and selling my old onesEdited by: lewis294