5125sc

I have a 2003 QC 3500 dually with the RAZP code cd / RCKP 7 speaker Infinity stereo and would like to add a subwoofer to the system. Can I run an external amp off of this stereo or should I look at a powered sub like the Bazooka tube?

What are other QC owners doing for stereo upgrades??

BigBlue

I've replaced my headunit, added front components with an amp, new rear speakers, and 2 12's under the back seat. Your gonna need an adapter to convert the head unit into RCA's (circuit city or best buy should know what I'm talking about) so you can run RCA's to an amp.

cquestad

Yes...an additional amp can be wired into the stock system. Somebody a while back posed a link to a bunch wireing diagrams depending on what you wanted to do. Basically you will splice a line level to preamp out put converter into the stock system somewhere and have at it.

oscaroc

Some Alpine Amps And others) have a line level input on them already. you just connect existing speaker wire into, then out to you subs. I don't know how good it sounds doing it that way.

gatf4

I installed an MTX Thunderform box with a single 10" Infinity perfect series Sub with Dual Voice Coils under the passenger rear seat. I did have to remove the fold flat floor on the passenger side so you will loose a little storage. l tied into the Infinity sound system with a speaker level output to RCA converter in the passenger side kick panel. I put an Infinty 710 series amp under the drivers seat (just barely fits) that has an optional dash mounted control **** for the Sub level that allows you to turn it off completely if you want from the dash. The sub kicks real hard and is very punchy. IMO it blends perfectly with the factory system and is plenty loud. Most of the time I can only handle the amp control **** being up about half way. I bought everything from Crutchfield for about $700. You could use a cheaper amp and sub and probably do it for around $500. They gave me the wire colors for the front door speaker wires that I tied into.

Just be sure not to tie into the rear door speaker wires because those are already crossed over from the factory and don't produce any bass, only mids/highs. I learned that the hard way, I finished the whole install using the rear door speakers and fired up the system and it had no sound from the sub at all oops. Also, this will allow you to turn down the bass almost all the way on the head unit so the rest of the factory system can sound cleaner while at higher volumes. Depending on the CD I can turn most of mine up to MAX Volume and they still sound real clean, and loud enough. Good luck