Model 3 SR+ rear deck/shelf speakers replacement

Joined
Aug 9, 2019
Messages
7
Location
Laval
Tesla Owner
Model 3
Country
Country
#1
Following this tread from @PLUR, I was very pleased with the improvement provided by connecting the tweeters and read deck speakers (via the Alpine KTP445-U Amp). Not long after, I realized how unbalanced the newly installed front Infinity REF-4032CFX sounded compared to Tesla's stock speakers. The stock speakers seem to have an annoying peak around 450/500Hz (+10dB measured with a phone app). Furthermore, the "Immersive" setting seemed to amplify this unbalance (btw "Immersive" does nothing to the front deck speakers, but alters the rear speakers considerably to "spread the stage"). Soon enough, these frequencies were all I could hear. And so, I embarked on replacing the rear shelf speakers with the same Infinity speakers as the front.

Here's how it got done. The guinea pig below is a Model 3 SR+ built in July 2019, but I suspect the process would be quite similar on the other Model3 configurations. Beware, it takes time and patience to work these panels to not break trims or end up with rattles. Removing and installing the deck took me about 1-2hr each way. Preparing the deck, another 2-3hours.

Steps:
1) Remove the rear seat
2) Remove the side seat (continuation of the back rest of the rear seat, not sure what the real term is)
3) Remove the (B?) pillars, the ones covering the side curtains (airbags)
4) Remove the plastics (trims) around the rear (small) windows, and slide out the one around the seat belt into the trunk
5) Remove the two push pins holding the rear deck behind the rear seat and separate the read deck from the sound insulation material. Disconnect the rear brake light and OEM speakers
6) Then the rear deck kind of slides out, towards the cockpit of the vehicle. Be very careful here, there are several wires, including the radio antenna ribbon which is quite fragile. Eventually, you end up with something like this:
20190907_095242-jpg.29060

7) With the rear deck in hand:
20190907_094812-jpg.29061

7a) Side note: There are no trunk cutout on my SR3+. Some have discussed that a cutout was there for HVAC system (providing an airflow path), but not in my (Canadian) SR+ car.
8) The rear grill can be separated by bending the tabs (tabs shown above):
20190907_111924-jpg.29062

9) Remove the Tesla speakers
10) This is where I was nervous, I was not sure if the bigger magnets of the Infinity would interfere with the metallic structure of the deck (the Tesla speakers have tiny magnets, and the rear structure is shaped accordingly). It turned out that, even with the Infinity speakers mounted where the stock speakers sit, they did not touch the structure (good news). But if I pressed (considerably) of the deck, I could hear then touching the structure. Sketchy... I did not go through this trouble to trade frequency peaks for rattles.
11) And this is where I got lucky. The stock speakers were "Repurposed" to make a shim between the rear deck and the Infinity speakers. The fit to the Infinity's are perfect and it lifts the speakers by about 1/4" (more than enough). Take a deep breath, start cutting, filing and sanding to extract the ring around the OEM speakers. (Ok, I took a lot of measurements before busting out the hack saw, so it looked good before hand).
20190910_210951-jpg.29064

Fit to the Infinity speakers is fantastic:
20190910_211048-jpg.29066

12) Cut off the unused ear of the Infinity's and start reinstalling. Note: I squeezed the foam provided with the Infinity between the speaker and the ring (from the repurposed OEM speakers). Not a good idea, it put a lot of pressure to a point where I stripped the plastic (hence the painted screw and washers). If I had to do it again, I would not use the foam there.
20190910_212950-jpg.29067

20190910_222149-jpg.29068

13) Clean the deck and reinstall the grill (re bending the tabs):
20190910_222425-jpg.29071

14) Solder, insulate the speaker connectors and dress the new wires:
20190911_200408-jpg.29069

14a) Note that I used a bit of foam around the magnet of the speakers; last line of defense to prevent the magnets from touching the structure. I don't think it's necessary, but I hate doing things twice...
15) While removing the rear deck, I noticed that the structure was heavily resonating at 75Hz. While at it, I also used a bit of foam tape to dampen the resonance (squishing the read deck and the structure):
20190911_195922-jpg.29070

16) Slowly work the rear deck back into the car. Take your time, there are a few cables to route, and others not to break. I found pulling back on the insulating foam (provided by Tesla) before working in the deck was necessary.
16a) Don't forget to reconnect the braking light.
17) Test that everything works and reinstall the trims.

Worth it, you ask? ABSOLUTELY! The 450/500Hz peak was attenuated tremendously (I still have the rear door stock speakers... for now), happily to an acceptable level. The foam strips added to the deck greatly reduced the trunk's resonance. Sound is MUCH more balanced, and I can use the "Immersive" setting without getting angry.

Good luck!
 

PLUR

Active Member
Joined
Sep 7, 2017
Messages
48
Location
westmisnter
Country
Country
#2
Great write up! Do you happen to have a pic of how the bottom of grill with the tabs look like? Do you think there is even a chance of just prying the grill out from the top without removing everything, and have access to the speakers for removal/replace? Kinda like how the front dash speakers are replaced by removing the grill. I understand there might not be enough clearance and wire length but I'm curious. Thanks.
 
Joined
Aug 9, 2019
Messages
7
Location
Laval
Tesla Owner
Model 3
Country
Country
#3
Right, the front grill kind of clips in place. I doubt it can be done for the rear grill without breaking everything. The grill is shaped into to tabs as shown below (boxed in red). These have to be bent +90Deg for the grill to come out.
rear-grill-tabs-png.29102
 
Joined
Jun 22, 2019
Messages
12
Location
NC
Tesla Owner
Model 3
Country
Country
#4
Awesome! Thank you so much for this information. I just upgraded the front three speakers to Infinity REF-4022cfx in my SR+ and I'm determined to replace the rear deck speakers and add an amp to drive them plus a modest subwoofer. The front Infinity speakers are so clear from the upper-bass through the highs that I want to get that same sound coming from the rear deck.

My biggest concern was whether there is enough clearance for the REF-4022/4032 magnet. The speaker is about 1/4" deeper from the mount to the magnet. Your approach of using the ring as a shim makes up for the 1/4" difference.

For the 3rd screw over the edge of the speaker, maybe I can shim the screw with some soft washers to try to keep the top washer level while still keeping pressure on the edge of the speaker ring.

Questions on the procedure steps:

1. You mention removing the backseat. Do you mean the bottom of the back seat and then fold down the backs of the back seat or do you really need to remove the seat backs too?

2. Other folks mention that removing the pleather side trim pieces will break a clip. Did you also break the clip or is there a trick to not breaking the clip when pulling out the trim?

3. I think Tesla calls the airbag cover in the back the "side rail" in the parts catalog.

4. Does the window trim just pull straight out with clips?

Now I just need to find someone with a left over REF-4022 to go with my left over one from the front upgrade.
 
Joined
Aug 9, 2019
Messages
7
Location
Laval
Tesla Owner
Model 3
Country
Country
#5
Awesome! Thank you so much for this information. I just upgraded the front three speakers to Infinity REF-4022cfx in my SR+ and I'm determined to replace the rear deck speakers and add an amp to drive them plus a modest subwoofer. The front Infinity speakers are so clear from the upper-bass through the highs that I want to get that same sound coming from the rear deck.

My biggest concern was whether there is enough clearance for the REF-4022/4032 magnet. The speaker is about 1/4" deeper from the mount to the magnet. Your approach of using the ring as a shim makes up for the 1/4" difference.

For the 3rd screw over the edge of the speaker, maybe I can shim the screw with some soft washers to try to keep the top washer level while still keeping pressure on the edge of the speaker ring.

Questions on the procedure steps:

1. You mention removing the backseat. Do you mean the bottom of the back seat and then fold down the backs of the back seat or do you really need to remove the seat backs too?

2. Other folks mention that removing the pleather side trim pieces will break a clip. Did you also break the clip or is there a trick to not breaking the clip when pulling out the trim?

3. I think Tesla calls the airbag cover in the back the "side rail" in the parts catalog.

4. Does the window trim just pull straight out with clips?

Now I just need to find someone with a left over REF-4022 to go with my left over one from the front upgrade.
1. Correct, just removing the bottom seat and fold down the backrests
2. No clips were armed in the process, take your time
3. Ok good to know
4. Kinda. Start pulling the window trim from the center of the car, and slowly work the clips up to the rear of the vehicle. Interestingly, the driver side was far more stubborn than the passenger side for me. Again, take your time.