Lesson learned: Not all OEM stereos are made the same...

Troysterr · **Posted:** Sat Jan 12, 2008 6:02 pm

The CD player in my head unit stopped working (worked intermitently for a while, then just died) a while ago, so I considered getting a new aftermarket stereo from Crutchfield, but decided that I'd rather keep the OEM look.

So I found what I thought was roughly the equivalent of my OEM head unit (AM/FM CD + cassette), except with out the cassette player, on eBay for $70. Not bad, considering I only listen to CDs and radio.

So I just installed it. Big mistake. Not only does it lack some basic display features that my old stereo had (like showing volume and bass/treble settings when you change them), but it sounds like TOTAL CRAP! :roll:

When I bought my KJ I got it with the premium sound. I guess that's what the difference is. I thought it was just the Infiniti speakers, but apparently the HU itself is much better than the base stereo. I feel sorry for those of you who have the low-end sound! Seriously, it was like I went back 30 years to my dad's old 64 Chevy pickup and its mono AM radio!

So, I put my old stereo back in, and I guess I'll be trying sell this piece of junk and get a decent aftermarket HU from Crutchfield, after all.

Frostednutz · **Posted:** Sat Jan 12, 2008 7:51 pm

heh thats because i believe the premium comes with 4 infinity speakers and a single subwoofer?
OEM radios are very picky so good to hear you're going with an aftermarket radio. I heard of
people having problems when installing the premium sound though. let me know if you need
any help or advice on equipment.

JL Rockies · **Posted:** Sat Jan 12, 2008 10:46 pm

The infinity system probably has an external amp and the deck is low level out. The base system has hi level out. It probably sounded bad because you were ramming a lot of voltage up the amp's butt. Or (and), the infinity speakers are low impedance which would not be compatible with the second deck's amplifier section.
If either of these conditions exist in your Jeep, an after market deck is not the solution alone.

There is no significant difference in the quality of the signal coming from the base, infinity or after market deck. I use my stock deck as the source for my system without problems.

If there is an external amp, it will need to be bypassed if the speakers are low impedance, they will need to be changed. Unless you replace the deck with another OEM infinity.

You really should see Ryan at Car Concepts in Murray.

Or I could have a look at it for you, but our schedules never seem to mesh.

JL Rockies · **Posted:** Sat Jan 12, 2008 10:53 pm

Pull one of your front door speakers. You probably will see the amp attached to it if I am correct. You'll need to bypass each amp for the deck you have now or any after market deck to work.

Troysterr · **Posted:** Sun Jan 13, 2008 12:44 am

Well, that all makes sense.

Besides wasting a bunch of time on my stereo (my original CD player is working again by the way), I spent the rest of the day trying to figure out how to get the wires for my Hella 500s through the firewall. I looked at Corwyn's instructions on wiki, pulled, tugged, groped, pushed, and poked, but I could never figure out a way to do it.

Bottom line: I shouldn't try to do anything to my own vehicle. I'll do what I do well and let others do what they do well. Talking to Ryan sounds like a GREAT idea. Thanks for the tip.

Frostednutz · **Posted:** Sun Jan 13, 2008 1:38 am

there might be a crossover but whether it's in the door or not i wouldn't know. i tried putting my crossovers in the door but it
didnt work out so well because it got wet all the time and rusted over a bit. i just tucked it away in the fuse box panel

if all else fails run a cheap 5 channel amp 4 channels for front and rear speakers and 1 for the subwoofer. reason i
suggest this is because even though it's premium sound from infinity stock still sucks. well unless you buy the new
posche with the bose system in it that ones pretty decent i heard.

Troysterr · **Posted:** Sun Jan 13, 2008 1:47 am

Well, I dunno...I've always really enjoyed the sound quality in my KJ. I've had expensive, professionally-installed stereos with amps and subwoofers before, and I'm sure they impressed people who cared, but I have simple tastes. As long as the sound is clear and loud enough to hear over my BFG MTs, I'm happy.

Pardon my ignorance...but don't aftermarket stereos have pre-amp outs specifically to accommodate external amps and amplified speakers? So, for example, if I bought a head unit with 2 or 3 pre-amp outs, would I still have to bypass the amps on the speakers?

JL Rockies · **Posted:** Sun Jan 13, 2008 2:17 am

The OEM amp most-likely uses differential inputs. I don't know of any after market deck that uses differential outputs. Most decks signal ground is common to chassis ground. It would not hurt anything, but it would be noisy. The OEM amp is not going to have a sensitivity adjustment either, so you'll need to know the voltage output of the OEM deck and try to match it. That would probably not be possible.
If you want to add another deck, you'll need to cut the amp's input wires and connect them directly to the output wires (bypass) or run new wires to each speaker.
I have an automatic so I drilled a hole in the knock out in the firewall meant for the clutch pedal when I ran wires for my stereo.

Frostednutz · **Posted:** Sun Jan 13, 2008 2:52 am

aftermarket decks all have high level outputs (the very small gauge wires) and the better models will have a low level sub out (RCA connections) but the better ones have the front/rear low levels along with the sub out low level but the best will have dolby digital suround sound which have front/rear/center/suround front/soround rear/sub out and a whole mess of cables you are unlikely to use. i just havent had time to mess with them... yet :twisted:

if you're looking for a casual audio exsperience just add an aftermarket radio with a 4 channel amp and put 2 sets of components one set for the front and one set for the rear and you won't even need a woofer. best thing to do is get rid of stock go with a decent brand... *cough* focal *cough* and you'll be supprized at how good it does sound...

Lesson learned: Not all OEM stereos are made the same...

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