Jeff928S4

1989 S4 - 10 speaker system

I am having an Alpine CDE 125BT installed tomorrow and in talking to the stereo place on the phone I was getting a lot of "We might need to put in a 4-channel amp to make all the speakers work......the 2ohm speakers will heat up the deck....." talk.

Here is what I want them to do....

1. Install deck
2. Run speaker wires off of deck harness to amp and by-pass amp, hooking the wires up to the existing car's speaker wires.

Now, I could pretty much do that myself, but I don't know about the power supply/antenna/alarm stuff. Is that something I could do by myself?

If they run the deck to the factory speaker wires, it that it? Do they need to add an amp to make all the speakers run?

Also, what about the alarm - anything special I should tell them or will they know what to do?

Maleficio

The schematic will tell you everything you need to know.

blown 87

I got a hundred bucks that says you know far more about a 928 than the radio installer does.
I can not count the times that electrical problems are tracked back to some aftermarket radio installation, done by some one who is getting paid to take short cuts and does not care about your car.

I strongly suggest that you do this work yourself.

Jeff928S4

...searching now....

danglerb

I would not hand my 928 over to any car stereo shop.

Maleficio

Blown87 and Danglerb are right.

I did my install, and mine was more difficult than yours will be because all of my speakers are installed behind the panels. I had to do some serious panel-pulling in the middle of the summer heat without shade just to replace four old speakers.

It was worth it, though. Sounds incredible.

dr bob

Generally, the two-ohm speakers are within the capability of the head unit. It will only add to the heat load in the head amp if you turn it up louder, and no more than if it was switching 4-ohm speakers actually. Watts are what causes the heat, and with the low-impedance speakers you swap voltage for higher current. But Watts are still Watts.

That said, the original drivers in your car are crispy at best unless they've been packed in a time capsule by hermit seals. The technology for car speakers has changed dramatically since our cars were built, particularly in magnets and other materials for the cone and support for it. Our original Bosch/Blau speakers are varnished paper with now-torn varnished fabric surrounds. Bottom line: invest in better speakers as part of your installation. You'll find that the rear mids (too often incorrectly referred to as subs or woofers) on the B-pillars are a good place o put a true mid-range speaker. Along with the door locations of course, where separates will give you the best sound field. Supplement those with directional tweeters at the a-pillars. If you want to have actual bass, somehow you'll want to add some bass drivers, and for those you'll want an amplifier. Once you are committed to an amp for bass, it's easy to buy a mult-channel model to drive all the speakers. Slippery-snowball effect.


Good luck with your project, and be sure to post pics and overll impressions of your install when it's all done.

Jeff928S4

I do fear them tapping into the fuse panel and things like that.

Heck, when he looked up the car, the only info he had on file was the GT and the GTS - no S4 at all.


So....the speaker wires I think I got covered.

Now I as for output on the new deck, I have.....

1. "Antenna" (looks like a straight plug-in?)
2. "Power antenna" - I take it I wouldn't use this
2. "Remote turn on" - do I hook this up to anything? The book says "to amplifier"
3. "Audio interrupt in" - huh? Says "not used" in book
4. "Illumination" - again, huh? Book says "to the instrument cluster lead"
5. Ignition - I assume I'd spice this to the "Ignition" wire on the cars stereo harness?
6. "Battery" (is this the power supply?) - splice to car's harness?
7. GND - I assume this is the ground and I can put it where the old deck was grounded.

Basically - if I cut the wires going into the car's harness and straight wire the decks wires (Ignition/Battery) to these wires, will this work?

Ducman82

Remote power is for turning on an amp if you have it, when the radio turns on.
3. dont use.
4. is for dimming function. so when you dim your dash, it dims the radio

Jeff928S4

I am pretty lucky - the car I have sat in a showroom for a few years, so the smaller speakers seem to be in good shape. The rear 6" speakers rattle like crazy - thus me doing a re-foam on them this weekend.

Eventually I will be replacing all speakers and adding a small sub/amp, but for now I just want to listen to something other than the radio, as my factory CD-2 will not play CD's anymore.

I figure the new deck and working 6" speakers will make a nice enough difference for now.

ender928

+1 to what everyone is saying. My stereo installation pretty much ruined my car. Don't know wtf they did but it wasn't pretty. So either do it yourself or take it to someone who knows these cars.

dr bob

The remote power for turning on the amp should be used to turn on the amp. You have an amp in the antenna circuit that needs power, so this the connection for that wire, usually bundled/wrapped with the antenna coax. If you add an audio amp, you'll need this wire connected there too.

The always-on battery power comes through a connector by the amp next to the pasenger seat. If you unplug the amp that's there now, you'll need to add a jumper inthe connector. The original amp senses the current flow to the head unit to turn on and off.

The illumination wire needs to connect to the existing dash illumination wiring.

Ground is ground.

The original intallation has an alarm wire connected through the DIN sleeve. It's electrically parallel with the hood switch for alarm purposes. Don't leave it dangling or you risk erratic alarm operation and unexplained no-starts.


Stefan Weiss at SWStereo offers plug-and-play harness adapters that let you plug moderh head units into the existing car connectors with no cutting or splicing. Based on the questions presented so far, this might be a good pain-free option. It also lets you keep the car relatively unmolested electrically. Too many horror stories are floating around about half-fast stereo, alarm and car phone installers who have caused significant problems immediately or, worse, later. The list isn't limited to so-called "pro" installers either; well-intentioned DIY disasters dot the landscape too.

Jeff928S4

Good stuff - that eliminates a few things.

I won't worry about the illumination thing, as I always have my dash as bright as possible.

So that leaves the ignition and battery. In reading some searches, it turns out the power supply runs to the amp first, then to the deck? So, if I am eliminating the amp, I'll have to run wires from that location back to the deck, yes?

Here is what I am thinking.....

- 4 speakers wires from deck to amp location - splicing into car's stereo wires that come out of amp
- Run power wires from amp area back to deck and splice into deck's wires
- Tap into car's antenna from deck

Can I tap into the car's ignition wire behind the deck or is that also down by the amp?

So far, this seems do-able - but what about the alarm?

Edit - just read that the amp has 3 sets of speaker wires coming out of it? But I am only going to be running two sets of wires to it? How does that work?

dr bob

Be aware that the factory 6" drivers are unsealed at the back and provide no meaningful low end. Many (including me) have grafted modern 6.5" drivers there into the orignal housings to keep the stock look. Still, audio quality comes up way short. I ended up putting a coaxial driver there with a simple cap 'crossover' (filter) built in. My door speakers are originals with supports replaced, mostly for the original appearance. Sound is mediocre at best, even with a good head unit driving them. I sounds no worse that the way it sounded when new, by the way.

During a very serious interior cleaning that had the carpets and seats out, I added all the wiring for a future amp and speakers install. It all home-runs to the amp area by the passenger seat. At some point, there will be a reasonable-quality amp that will fit under that cover. Until then, everything plugs together there in anticipation.

Jeff928S4

Found the schematic - I have the WSM -duh!!

....and I can't find anything - only section 91 for adding a phone