Rear Speaker and Amp Replacement
1997 Cadillac Seville with Bose sound system
May also apply to similar year Seville's and Deville's

Introduction

The rear speakers and amps of the Bose sound system in the 1997 Seville are of pretty good quality. However, if you insist on having the best, or if one or more of the rear speakers or amps are damaged, this guide will help aid you in replacing them. Listed below are the steps required to accomplish the task. Text in blue boxes relate specifically to my own installation.

If your system is operating normally, and you are thinking of replacing the rear speakers and amps with locally purchased medium-quality equipment, don't bother. The Bose speakers and amps will likely sound just as good or better. You will only hear an improvement if you buy top-of-the-line speakers and amps, which usually means ordering them.

My particular install used the following equipment:

If you go strictly by the numbers, the amplifier is slightly overpowered, but I already owned the amplifier (purchased in 2001). And the Infinity Kappa speakers were some of the highest RMS rated 6x9s I could find (in addition to being all-around top-of-the-line). Originally I was just going to replace the Bose speakers with the Infinity speakers, but later decided to build an enclosure that would allow me to use both sets simultaneously.

The Basics

Equipment you will likely need:

In order to replace the speakers and amps, you will need to remove the trunk top-front panel (the panel covering the top and front of the trunk), the rear seat bottom, the rear seat back, and the rear deck cover. You may need to remove additional parts depending on where you mount the new amp.

Trunk Top-Front Panel

To remove this panel, unscrew the 4 long plastic push-nuts on the top of the trunk (no tool required). Remove the panel. Once removed, you will be able to see the amps and bottom of the speakers, as well as the plastic panel that rests between the rear seat and the trunk that has numerous electronics modules mounted to it.

Rear Seat Bottom

The front of the rear seat bottom has a latch holding it on each side. The latch simply pops in and out like a snap. Grap the seat near the latch and give a quick firm upward pull to free the seat bottom on each side. Carefully pull out the seat bottom, making sure not to snag anything that might be under it (aftermarket components may be placed or mounted under the seat).

Seat Bottom Removed

Aftermarket cell phone equipment was haphazardly installed under my rear seat. In this photo you can also see the seat belt buckles and brackets. Click the thumbnail image to view full size photo.

Rear Seat Back

Remove (or loosen) the 2 seat belt buckle retaining nuts. (tip: note the orientation of the seat belt buckle brackets so that you can make sure they are positioned correctly when re-installing the seat back). It is not necessary to completely remove the nuts as the seat back (NOT seat belt) brackets are open on the end and can slide out after the nuts are loosened. However, removing the nuts may make your job a little easier. Now, from the trunk, remove the two small nuts with large washers at the top corner of each side. You should now be able to remove the seat back.

Seat Back Removed

If you mount anything to the plastic wall, be careful not to damage any of the electronic modules already there. In my case, the amp was installed on the opposite side of the black module in the upper left of the image. The amp is larger than the module, and the four amp mounting points are each an inch or two away from each corner of the module.

Rear Deck Cover

With the seat back out of the way, you can now easily work with the rear deck cover. Remove the three plastic retaining plugs. You can pry them out using needle-nose pliers. Now slide the rear deck cover forward and out.

Speaker/Amp Removal

Simply unplug the 4-conductor plug near the speaker and pop the whole speaker/amp assembly up and out of the plastic retaining clips. Make sure to remove the plastic retaining clips as well.

Bose Amp

Here you can see the bottom of a Bose speaker and amp. You can see the 4-conductor plug to unhook at the top of the image.

Bose Amp with Cover Removed

A look at the Bose amplifier with metal shell removed.

New Speaker Install

It's not a bad idea to have some kind of gasket or seal between the speaker and the rear deck. You can probably salvage the seal off of the old speakers. Since the old speakers used a special frame with plastic retaining clips, you will need to mark and drill screw holes for the new speakers. Marking and drilling from the top won't be easy due to interference from the rear glass, so hold the speaker up in the trunk as if you were going to rear-mount them in order to mark the holes. Then drill them from the bottom. Now just drop your new speakers in from the top and secure.

Infinity Kappa Speaker

A look at the Infinity Kappa 693.7i speakers used in my installation.

Speaker Mount

I decided to install the Inifity speakers in addition to, rather than in replacement of, the Bose speakers. The rear deck was not well formed for simply cutting a second set of speaker holes, as the surface is anything but flat. I therefore decided to build separate mounts that would hold two speakers each and mount below the existing speaker holes.

New Amp Install

There are many places you may consider mounting the new amp. Whatever place you pick, make sure that the amp has sufficient cooling and be careful when drilling holes. There are alot of expensive electronic modules and other obstacles to watch out for.

In my application, I mounted the amp to the front of the trunk on the plastic panel that rests between the trunk and the seat back. There are alot of electronic modules mounted to this panel, but I was able to find a nice spot on the right side of the panel where all four amp screw holes would be free of obstruction. This panel is not perfectly flat, so I used half-inch nylon spacers to hold the amp above all the uneven plastic ridges. It was also necessary to carefully cut out a hole for the amp in the trunk top-front panel (there is insufficient room to hide the amp behind the panel).

I consider this location ideal in that it makes the amp visible in the trunk yet out of the way, provides good cooling, and keeps the amp close to the speakers.

Mounted RF Amp

Rockford Fosgate 250.2 amplifier immediately after mounting.

Mounted RF Amp with Trim

This is what it would look like with just one set of 6x9's installed.

Mounts Installed

A nearly finished installation. The speaker mounts are installed. The original Bose speakers are on the other side of the mounts. Due to clearance problems, I had to move the Bose amp on the right side; you can see it installed on the side of the speaker mounts.

Mounts Finished

Finished installation with trim panel in place. For an even better look, I plan on carpeting the mounts at a later date in the same color as the rest of the trunk. The trim planel had to be cut out quite a bit for the amp and speaker mounts. A sharp razor works well for this.

Wiring

The wiring, to the best of my knowledge, is as follows:

Each side has both an orange switched power wire and a black ground wire. Each side also has two other wires which are low-level pre-amp outputs from the head unit.

Right SideLeft Side
PositiveBlueBrown
NegativeBlackBrown w/ Stripe

Wiring Diagram

Above is a simple wiring diagram of my system. I tapped the power for the Bose amps, which are switched, and used it as the remote turn-on power into the RF amp. The power for the RF amp is provided by a 10 guage wire with a 30 amp fuse, ran along the passenger side of the vehicle under the trim panels.

I am almost entirely certain now as to which wires are positive and which are negative. To figure this out I tried different wiring configurations, altering the balance to test bass response between speaker pairs. If the bass response is better with two speakers working together, then they are both hooked up right or both hooked up wrong. If the bass reponse is better with just one speaker, then one is hooked up right and one is hooked up wrong. I was then able to figure out, with a rough certainty, which wires were which by using the original Bose speakers as a control (since I know they are hooked up correctly).

Noise Testing and Correction

Before you put everything back together, it is advisable to run some noise testing. Once you have the new system hooked up, take your car outside, start it and let it idle, have the radio on at low volume, and listen for electrical noise from the engine or other electric systems. Try reving the engine, turning the head lights on, adjusting the dimmer, etc. If the noise levels are unacceptable, make sure you have a good ground. If you know the ground is good, try purchasing and installing a ground loop isolator (tip: look at how the ground loop isolator connects into the wiring while at the store -- you may also need to buy couplers). You can also try a noise filter on the power line if all else fails. You can usually buy these items at places that specialize in car audio, or at Radio Shack if there are no car audio professionals in your town.

I had alot of electrical noise in my system when I first turned it on. All of the noise came from the low-level inputs to the amp. The noise was eliminated by installing a ground loop isolator.

Additional Images

Rear Left Speaker Rear Fuse Box RF Amp Closeup

Last Updated 9/28/2005 by Scott Arnold Valid HTML 4.0 Transitional