View Full Version : Aftermarket headunit with the factory 10 speaker "premium" sound

05-13-2012, 05:08 PM
I've been trying figure this out for a little while but with no avail. I have a 1994 firebird formula with the factory 10 speaker "premium" sound system. From what I've gathered so far, this consists for 8 speakers front and rear, and 2 6.5" subs powered by a 200w amp in the sails. So my problem is that when I go to hook up a Kenwood KDC-108, everything will work except the sails. Because of this there is no bass and it sounds awful. What must I do to get the sail speakers working with the aftermarket stereo? They work fine with the stock one, but the tape deck in it is broken so I need a replacement. Any help would be appreciated. Thanks

05-14-2012, 03:51 PM
If you used a harness adapter when installing your head unit, the speakers should work exactly as they did with the factory head unit.

05-15-2012, 02:44 AM
I did use a wire harness adapter where you crimp all the wires to the harness of the radio. I double checked the make sure none of the polarities were switched and everything looked fine.

05-15-2012, 08:10 AM
Have you checked the fuses? I believe the amp is on the RADIO ACCY fuse in the dash fuse panel. If that fuse is blown, all speakers except the amplified sail panels would work.

05-15-2012, 08:03 PM
Well since the amp works with the original headunit plugged in but only when the kenwood stereo is installed I'm pretty sure the fuse isnt the problem? I'll check it anyway, but perhaps it a problem with the kenwood headunit? not being able to drive the amp? I dont know much about audio as I'm new to it all, so any help would be appreciated. Thanks

05-15-2012, 08:32 PM
The sail panel subs do not have a separate source channel. The system uses the standard four channel output of an ordinary head unit and splits it among the 10 speaker elements. So, if everything works when you take out the Kenwood and put the OEM head unit back then there is something wrong with either the Kenwood or its wiring - the rest of the system is fine.

You have removed the Kenwood and replaced it with the OEM head unit, right? Because if you haven't then you should... to test that the system still works after the Kenwood was installed.

05-15-2012, 11:30 PM
Yeah I removed the kenwood and went back to the oem headunit cuz it sounded like shit.
Everything works fine with the stock unit. So you think its the kenwood thats at fault?

05-16-2012, 07:57 AM
It is definitely something related to the Kenwood (as opposed to something in the car like the amp). The first thing is to double check the connections on the wiring harness adapter - make sure all connections are correct and that they are tight. If you used crimp on connectors, you might want to consider switching to solder and heat shrink. Also check that none of the pins in the connector are bent or broken. If possible, do a reset on the Kenwood head unit to be sure that there aren't any settings that may have turned off speaker channels (i.e. sub output enable, fader, dual zone, etc.).

If all that checks out and it still doesn't work then it's probably safe to assume that the head unit is the problem although it would be nice if you could try it in another car to confirm. Just about any GM (non-Bose) vehicle from 1988-2000 would be wired the same.

05-16-2012, 02:53 PM
Also make sure that all 4 channels (2 front / 2 rear) are actually turned on in the Kenwood. I recently installed an aftermarket headunit in a friend's car and for some reason, the stock setting had the rear channels turned off.

05-16-2012, 10:12 PM
I used solder and shrink wrap and just double-checked the connections and see no week spots. I plugged the kenwood in again and made sure all channels were on (it really doesnt have many options there actually wasnt even something to turn off channels) but either way i could hear the sound coming from the hatch speakers and the front just not the sails. I guess its safe to assume that I need a new headunit. Thanks for the help guys

09-19-2012, 04:54 PM
I'm having the same issue--I have a new head unit (kenwood 852) with a conversion harness, to the monsoon amp, and the sails are producing nothing. Has there been a fix to this?

09-29-2012, 11:40 PM
My sail panel speakers are not working either, after I installed my new Kenwood stereo.

The front door speakers and rear hatch speakers are working beautifully, and the sail panel speakers are totally dead.

I can't figure it out :bang:

10-01-2012, 08:58 AM
There is another thread about the same problem of losing sail panel subs after installing a Kenwood head unit. It seems to happen with Kenwood equipment in both the older 10-speaker premium system and the newer Monsoon system (similar but not identical designs). It has been shown that restoring the original head unit makes the subs work again so the problem has to be with the Kenwood head unit. There must be some setting that needs to be changed. My suggestion is to call Kenwood support because they likely have heard of this problem and know which setting to change.

10-04-2012, 12:48 AM
on my old 95 Formula I had the same system. There is a blue wire on the harness that connects to the antenna power of the stereo and that is what makes the amp work. Happen to me when I had the original plug of the factory stereo cut off by a friend. Check the wires. Also the 2 sail panel subs can be bridged :) in case you want to wire a real sub in the trunk without an aftermarket amp. Worked for me and sounded good.