View Full Version : Help with Head Unit

12-28-2006, 02:45 AM
Hello all, i'm 19 yrs old, a former Crutchfield Employee, and a Car Audio Enthusiast. My entire system is Rockford Fosgate EXCEPT my Head Unit. Right now i've got;

4" Dash Speakers, 6.5" 3-Way Door Speakers, 6.5" Component Rear Speakers. I've got 2 older 200 Watt 2 Way amplifiers (one powering door speakers, one powering component system), as well as a newer 250 Watt 2 way Amp powering my 12" Stage 2 Punch. As i said this is all Rockford Fosgate except for my head Unit a Panasonic 5110U. It's a decent head unit but since the day i bought it the cd player hasn't been working properly not to mention it's chrome face doesn't match the black dash of my 98 Jetta.

Here comes the question; i'm bidding on a Rockford Fosgate RFX 8102 Head Unit, it's black (it matches), and it's Rockford Fosgate (so i'm happy). However i'm 24 hours away from winning this head unit and it comes to my attention that there are no RCA outputs for a Subwoofer. I was wondering how i would go about connecting the Subwoofer to the headunit. Are there any special adapters i'd need?

All help is much appreciated. Thank You.

12-28-2006, 01:53 PM
That will ****.

You are going to need to get a line out converter for your rear channels. The problem with that is that your are amping your speakers, and I do not know where the limitation is for LOC powerhandling wise, let alone the input side on your amp.

Also, your subs will lose SQ.

And the other possibility:

Now, check to see if your Channel amp has an output RCA on it. If it does, do your homework and see if that RCA output is affected by your amplifier setting or not.

If you have an RCA output, and it ISN'T affected by your settings on the amp, you can do it the right way, it will just be harder. What you will most likely have to do is turn off any HPF/LPF processing on your deck. Then you will have to tune each channel on your amp, because now you don't have any filters to help your SQ out. (depending on speakers, I'd say try to get the front set to pick up at 80Hz and the rear set, depending on model, can be either higher or lower. if they are smaller than the fronts, I'd try 100HZ if you like playing it loud.) Once your speakers are back to satisfactory levels, you can plug a small RCA line in (2 footer should be ample) and run it to your sub amp. Then you should be set, with some tuning of course.

This is all IF you have the required equipment to perform this.

12-28-2006, 03:03 PM
thanks for the feedback. I think i'll go with the 2nd option.

I'm running a Punch 250 x 2 channel Amp, it's the only one of the 3 amps that has a Pass Thru for the RCA's. As far as i can find all changes i make to the Sub's Amp won't effect the Speaker amp i connect it to. So i'm going to have to try that out today with my current system (i ended up winning the E-bay Auction so the Rockford Head Unit should be coming soon).

I've been thinking about another option (thought i don't know if it's feasible). Are tehre RCA splitters? so i could conceivably run 1 RCA from the Head Unit and split it to connect to both Rear Speaker Amp and Sub Amp?

12-28-2006, 10:28 PM
I would use the rca outs on the amp to run the second amp. I have mine setup with the frontstage amp line out to the sub amp. Works very well.

If that doesn't work out , you can buy y-splitters for RCA cables at most any audio shop.

Remember to reset the gains on all your amps to account for the changes in input from the new head unit.

Unrelated but just an idea. Consider moving the 6.5" components to the front stage and the 3-way coaxials to the back. Set up properly, components typically provide much better sound quality than coaxials. Also, try running the system without the dash speakers to see if the imaging of the frontstage improves.