S90 (Sc-811) Replacement With Double-Din

[VolvoFan]

So I've got a '98 S90 now. It has an OEM Volvo HU, SC-811. 8 speakers... one in each door, two in the dash, two in the rear hat shelf. There is some sort of amp-like box in the left rear trunk area behind the carpet, but there is nothing connected to the "AMP" DIN connector on the back of the HU.

I'm going to be connecting a JVC KW-NT3HDT double-din head unit that has a 4x50W amplifier built in (as well as a sub preout, which I will use). That is more than sufficient for me. Here's what concerns me... according to a wiring diagram that I saw for the radio, it has SIX speaker outs... the doors, then LF, LR, RF, and RR.

Any suggestions on how to go best wire the new HU? What stock crossovers are currently in place, if any? Should I wire stuff in parallel? Any suggestions would be much appreciated.

Thanks,

[BEJinFBK]

So I've got a '98 S90 now. It has an OEM Volvo HU, SC-811. 8 speakers... one in each door, two in the dash, two in the rear hat shelf. There is some sort of amp-like box in the left rear trunk area behind the carpet, but there is nothing connected to the "AMP" DIN connector on the back of the HU.

I'm going to be connecting a JVC KW-NT3HDT double-din head unit that has a 4x50W amplifier built in (as well as a sub preout, which I will use). That is more than sufficient for me. Here's what concerns me... according to a wiring diagram that I saw for the radio, it has SIX speaker outs... the doors, then LF, LR, RF, and RR.

Any suggestions on how to go best wire the new HU? What stock crossovers are currently in place, if any? Should I wire stuff in parallel? Any suggestions would be much appreciated.

Thanks,

With a wiring adapter kit, of course.

Less than 10 bucks and leaves the car wiring perfectly stock.

It's wires will match up color for color with your new decks wiring.

If you have an SC-811, this will work: http://cgi.ebay.com/ebaymotors/Volvo-V70-1998-Stereo-Radio-Wiring-Wire-Harness-Plug-_W0QQcmdZViewItemQQhashZitem5adb1e06b7QQitemZ390223234743QQptZCarQ5fAudioQ5fVideo

Let it take care of that pesky " six outputs" thing for ya and keep that install clean.

That unit in the back is probably a 6 disc changer controlled by the SC-811.

[VolvoFan]

With a wiring adapter kit, of course.

Less than 10 bucks and leaves the car wiring perfectly stock.

It's wires will match up color for color with your new decks wiring.

If you have an SC-811, this will work: http://cgi.ebay.com/...5fAudioQ5fVideo

Let it take care of that pesky " six outputs" thing for ya and keep that install clean.

That unit in the back is probably a 6 disc changer controlled by the SC-811.

Thanks, I was going to be cheep and do the ol' slice-and-dice, but I guess I'll go that way. Still not understanding how it's going to magically turn six speaker-level outputs into what I presume are four inputs required by the head unit, but I suppose I will plug everything in and then see what doesn't work, and go from there. Any idea what the max power rating is for the stock speakers? I am able to turn the gain down on the head unit so I don't blow anything and after dropping almost 800 bones on a HU, if I can avoid having to buy new speakers and an external amp, my bank account will thank me.

Oh, and the thing in the back (where I have seen amps and CD changers before) is just the trunk's air vent. It looks like an amp because it's black and square and has what appear to be heat-sink fins on it... they are actually louvers that allow the air in/out. Once I pulled off all the carpeting to get a closer look, it became rather evident that I had made an ass out of me and umption :)

[BEJinFBK]

Max power for ANY speaker is just about common sense.

If it starts to distort, turn it down. Back off the bass a little, whatever.

It's a not really a factor of "wattage",as much as it is about distortion.

As long as your sound is clean, they should be just fine.

Want it louder? Get a sub.

That'll get you well on your way to blastin' on the cheap.

[VolvoFan]

Max power for ANY speaker is just about common sense.

If it starts to distort, turn it down. Back off the bass a little, whatever.

It's a not really a factor of "wattage",as much as it is about distortion.

As long as your sound is clean, they should be just fine.

Want it louder? Get a sub.

That'll get you well on your way to blastin' on the cheap.

Sub is on the way. HU has an RCA-level out for it, so I can go right to a mono amp. will build a box for behind the rear seat and mount an Alpine 300W with a single Alpine 12" sub. Still curious as to how six speaker-level outputs will be properly combined into four by a magical five dollar eBay wiring harness!

-Jon

[BEJinFBK]

If you click the eBay link and have a look at the pic, you'll see leads for the dash

speakers flying from one connector to the other. They parallel the doors and dashes there.

It's a nice, slick wiring kit. A handful of connectors and a few ty-wraps, Boom - Done!

[VolvoFan]

Nice... I did look when I purchased and did notice that... was hoping that was the case so I don't have to do anything but solder, plug, and play! Does this mean that the new HU will see four 4 Ohm loads?

My SC-811 is a little flaky so I want to make sure I get some CD-quality sound coming out of a new head unit before I start chasing down potential speaker issues... no way to tell right now if it's the stock HU, the radio reception, the wiring, the speakers, etc.

To make the install even cleaner and more reversible, I'm actually going to use the M-BUS cable that's pre-installed in the car to route the stuff that has to go to/from the trunk. Namely, the subwoofer pre-out (RCA), the beeper signal from the backup sensors (single wire), the remote amp turn-on lead (single wire), the backup camera feed (RCA), and the GPS antenna (two wires). Thats eight leads. The M-BUS cable is an 8-pin DIN. Coincidence? I think NOT!!! I will fabricate male & female plugs with the appropriate receptacles for each end (i.e. RCA, 1/8" headphone, etc) and simply plug them into either end of the DIN cable, grounding the shield to the chassis.

The only cable I should have to route from front to rear will be the power lead for the subwoofer amp. I am totally open to suggestions here. I plan to use a ground loop isolator to make sure I don't induce any "hum" but if anyone has any recommendations re: a particular type of shielded cable, grounding location, etc, I'm all ears.

Thanks,

[Piston Slapper]

I have my 850's sub amp's power run as an unshielded 6ga line from the battery, through the main fuse box, down behind the dash, through the center console, and under the rear seat. Ground is a self tapping screw drilled into the top of the trunk fore of the lid. Didn't need any isolator, no hum at all.

I also have a harness adapter between my stock harness and my double din (Pioneer AVH-P3100DVD) which even included the line to the "parking brake light" to enable video playback. All the lines on the adapter were labeled with what they were.

[Modus]

here's my harness adapter: (Picked up at a local PC Richards)

Turbowire

Granted that there is only 4 leads for the speakers which means that yes the other 4 are wired in parallel groups.

Front left door and dash are wired together same for right door and dash.

Rear left door and rear deck wired together same for right rear door and rear deck.

50Wx4 channel amp running the stock speakers at 4 ohm stable.

100wx2 channel amp running 2 tens.

Not common practice in the digital age,

but I choose to be old school by adding an analog EQ that distributes my 4volt pre-outs to my amps.

My amps are located in the trunk, and the speaker feeds are then ran back to the wire harness for distribution.

4 AWG is ran from the battery through a circuit breaker, I hate fuses, through the firewall and ran under the sill of the 2 left doors.

Wine is present depending on how much gain my amps are tweeked at.

Ability to change any frequency on the fly priceless.