Okay.....
I've been discussing this w/ some of my friends and thought I'd post it.
I'm putting in a JL 4 channel 300W amp and 4 new Boston Acoustics speakers (5x7 in rear & components in front). I'd like to keep my stock head unit because it controls my 6 disc changer.

So.....will my setup sound good with the factory head unit or do I need to replace the head unit w/ something else (Double Din)? I invested some serious $$$ already w/ the amp & speakers.
The guy at the stereo shop told me the system would sound great with just using the factory unit because of the great amp & speakers I have selected.
Any opinions?

tim

 

I'm sure it will sound a heck of a lot better than the stock system. Most stock headunits have a good quality speaker level output, which when properly adjusted for with amp gain, can be very difficult to tell from a fancy aftermarket unit. I still have the stock "Premium" headunit in my L. It has some neat features, such as RDS, speed-sensitive volume control, big buttons, easy to use. Its tuner section really lets it down, though. I've never had a tuner get such mediocre reception. So.... out it goes first chance I get.

Be sure to pay attention to proper wiring techniques (good grounding, keep signal runs as short as possible and away from power wires, etc), and to set up the amp gain accordingly.

 

I did the same as you, stayed with the facotry HU. I have no complaints. System sounds excellent. I can't compare if it would be better with an aftermarket HU as I didn't do both. Pay attention to your HU speaker level outputs into your amp. You may want to invest in a high quality converter to go to line level and not use the ones in your amp if provided. I have heard that some of the amp built in ones aren't very good as the amp people feel you wouldn't be using them for a SQ system anyway. Most high quality amps don't accept anything but line level.

 

Did you guys ever experience engine noise with your setup? I just installed an MTX 4250, with Infiniti Kappa's in all 4 doors of my Expedition, kept the factory Head Unit, added a sub. And a bunch of engine noise is coming thru the system now. I used a Schosche FAI-3 line output converter, to connect the RCA's of the amp. I also ran the 4ga. power on the opposite side of the RCA's. What am I missing?

Thanks

 

bad ground? Where did you ground the amps? Did you remove all of the paint around the bolt you used? If your line output converter has a terminal that must be grounded, make sure it also is placed on a bare metal surface. On my old explorer, removing this ground got rid of my noise, but use that as a last resort. Make sure your battery terminals are clean also. A friend of mine had bad noise in his system, and it disappeared when he cleaned his battery terminals. Also, make sure that your gains on the line output converter arene't too high. This could also pick up some ground noise. Other than that, the only other thing I can think of is a bad alternator. If the diodes in the alternator go bad, they can cause extreme noise in a car audio system.

 

Yes, the ground is scratched and should be good. I mounted the amp under the front passenger seat, ran the ground up behind the passenger side kick panel (on the floor). The only thing I havent tried was turning the gains on the line out converter down.

You mentioned that the line out converter could possibly have a ground wire. Would this be in the line in side or the line out side? I may have just answered my own question since my line out is the RCA's. But it never hurts to ask.

Argh, bad alternator, dont tell me that.

 

The ground cable might be too long. Try grounding it closer to the amp. There also might be a ground loop. YOu might want to try grounding everything in the same place.

My line output converter had a ground terminal on it next to the speaker inputs, but not all do...