How to - Bose Door Speaker Cutout Fix (Amp)

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How to - Bose Door Speaker Cutout Fix (Amp)

Post by cs2000 » Sat Jan 06, 2018 4:08 pm

Hi guys, I'm a new 231 owner and my car has several of the "usual" issues these cars seem to have, one of them being the intermittent sound from one, or both door speakers.

How is it that after 7 days of ownership I know how to do this when the general consensus is that you have to buy the larger style relays? Well, y sheer coincidence, the amplifier modules in the Rx8 are EXACTLY the same as the modules in the Nissan 350z, which is my other car. On these vehicles the Amplifier controls the Subwoofer and I wrote the guide on the 350z club on how to fix that! Literally, the part numbers on the PCB match, so it is a simply copy + paste :) If anyone wants to see the original by me, its here ... t-fix-amp/

For some reason, Mazda decided to use a single simplifier for each door, I cant think of a logical reason for this but it potentially means youd need to do this repair on both sides if your suffering from these symptoms of this which basically are the sound from one side or the other cutting out from the main speaker, yet still plays through the tweeter. So lets begin.

Tools & Supplies Needed:
- Small flathead screwdriver
- Soldering Iron
- Solder
- Replacement Relay (links are below)
- De-soldering Wick (Optional, but makes it much easier)

Step 0 (Purchase the relay):

The relay can be purchased from two locations in the UK. These are listed below.

Farnell (£1.84, but minimum order value of £20.00) - ... dp/2008759

eBay (£2.97 with no minimum order quantity) - ... 108&ff19=0

In-case these links go down, the relay part number is "MULTICOMP - MCCMA51-S-DC12V-C - RELAY, SPDT, 12VDC, 20A "

Firstly, you need to remove the door card to get access to the amplifier module. For this first section there are no images,

Step 1 (Removing the Door Card):

Move to inside the door and using your fingers behind the small speaker pane (tweeter), pop this cover off. Let this hang somewhere out the way.

Next you’ll want to remove the inner door panel, which is held on by 3 screws and several clips. Start looking at the door handle, there is a small round cover where the first screw can be found. Use a small screwdriver to pry the little round cover off and undo the screw.

You can then remove the cover that is behind/around the door opening handle. You may need to pull on the handle just a bit to aid in removing this small cover. Note there are small plastic tabs used to hold the cover in place from behind, be gentle !

Next, you need to pry out the bottom of the window switch/door lock panel. Use a screwdriver covered with a small amount of masking tape to avoid scratching the piano black finish. Carefully pry the base away from the arm rest/handle panel. DO NOT pull this too far as there will be at least 1 electrical plug on the back of here (depending which side you're doing). Unclip these plugs and put the panel to one side.

The third screw that needs to be removed is at the back of the inner door handle pocket, near the armrest. Use a medium screwdriver to get this last screw out. A torch may help you see the screw, its at a kinda odd angle.

With all three screws now removed, you are ready to pull the inner door panel loose. There are nine (9) clips that hold the door panel. Working your way around the perimeter of the door, pull the panel to pop out the clips. CAUTION: DO NOT TRY TO COMPLETELY REMOVE THE PANEL AT THIS TIME. YOU ONLY WANT TO RELEASE THE NINE CLIPS.

Once the nine clips are released, the door panel can be pulled off the door by lifting it straight up. The door panel “hangs” on the window opening so it needs to be lifted off the window opening to come free. CAUTION: There are still two wire assemblies that need to be disconnected before the door panel will be completely free. You just want to lift the door panel off the door.

Now, you can either disconnect the remaining wiring connectors, or just work with them how they are, you call. Lets remove the Amplifier.

Step 2 (Removing the Amplifier):

You should see the small amplifier module to the side of the main door speaker. To begin with, remove the 3 screws holding this to the door, this will give you some room to work with the wires.

Next, unplug the square white connector from the top of the amplifier

Lastly, use a small flat blade screwdriver and GENTLY pry up the large long white connector from the end of the PCB. I'd advise prying one side, then the other, then returning to the original side etc, take it slow so you don't bend the pins.


Then take the Amplifier inside somewhere warm to start surgery!

Step 3 (Disassembly):

Next, again using the small screwdriver, lightly pry the metal lid from the rest of the metal case, a good place to start is the front retaining clip. as shown in the photo below, then do the sides and finally the lid should lever off.


The lid is held down by a small seam of foam with adhesive, so it will be a little bit tough. Be firm but careful and release the PCB from its metal housing, set this aside.

Now you can see the offending component. Its this Relay on the right-hand side of the shown picture, yours will be a grey box about 1.5cm x 1.5cm


Step 4 (The Doctor Will See You Now!):

From the picture above, flip the board over and use your soldering iron to remove the old relay, you have to de-solder the points shown in red below. I personally didn't have any de-soldering wick, so I broke apart the old relay, heated up each solder blob and used plyers to pull out the last metal legs of the old relay. I then re-heated the solder and inserted a pin through it to make holes for my new relay. You do whatever works for you, but be VERY careful not to damage any other components or to overheat the PCB as you risk burning off the copper traces.


Get your fresh relay and ensure you insert it correctly into the holes left by the old one. Solder this all in securely and fit back into the car to test. And relax! Picture below shows new black relay installed


You can do a similar fix by just cramming paper/card in-between the relay and the amp's casing, but eventually, even this will fail & for people like me who actually like the Bose system (despite its many many issues) a permeant fix like this isn't bad for a total cost of a couple of quid!

If you really struggle, drop me a PM, I may be able to do this fix for you if you can post me your amp.

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Re: How to - Bose Door Speaker Cutout Fix (Amp)

Post by Dazza44 » Sat Jan 06, 2018 6:00 pm

I don't have an issue with mine, but good of take the time to do a write up on this

Sent from my GT-I9505 using Tapatalk

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