DIY- OEM Style CF Coin Holder Bass Knob

[FromRagsToS4]

I felt the standard B&O sound system lacked low end. To address this, I installed Mr Spectacular's Driver side "Spec" fiberglass subwoofer enclosure for a sleek audio upgrade that didnt compromise on trunk space. Wanting bass control so as to not drive the wife and/or kids crazy, I was unsatisfied with any other location to mount the remote sub control knob besides where the coin holder is located to the right of the shifter.


Here's a pic of the final installed product:



Keeping in line with the stealth/OEM/sleek look, I decided I was going to use an OEM knob already present in the vehicle and figured the best one to use was the knob used for adjusting side mirrors. I would then have to figure out a way to retrofit the knob onto the post that the Alpine knob was pressed on to, and then figure out a way to mount the knob control pcb underneath the CF coin holder.

I purchased the CF coin holder from seller "diycarbon" on eBay, the mirror control switch button (P/N: 8K0959565F) from eBay (came out of a 2013 A4 Prestige S-Line), and the Alpine RUX-KNOB. Pictured below:






Most of my grinding I did with the dremel carving bit set 115.



Since the outer diameter of the plastic Alpine bass knob was exactly the same as the inner black plastic part of the OEM knob, I decided I would hollow out the OEM knob, cut the outside shell of the Alpine knob and keep the inside "crosshair" section intact.
Here is the OEM knob hollowed out:



I used a standard small Dremel grinding wheel to cut off the outer layer of the Alpine knob.



Here is the inner section with the outer "barrel" fully removed:



I kept trimming the side fins little by little until it fit snugly in the OEM knob (note the masking tape to keep the silver finish protected during work):



I mixed up some plastic epoxy and filled the OEM knob about 1/3 the way, then placed the Apline center fitting in, making sure to align it with the outer plastic "peak" on the OEM knob to make sure its pointing in the right direction:



Testing fitment on the post:



After taping the glossy CF with a few layers of masking tape, as well as the surface it was resting on, I used the Dremel tool (with the drill press attachment) to start hollowing out the interior of the CF coin holder so that the Alpine PCB would have the clearance to let the post through enough to use the nut to secure it:



Here is the hollowed out section inside the coin holder. Note, once I got close to the end, I was very careful to take very little off or else I would risk breaking through the other side or cause it to crack



Here it is after I got the post to stick through enough to put the washer and nut on securely:



Final product:



Got the switch installed in the car. Lots of work to relocate and run the wire!




Works like a charm!

[will13k7]

nice! I did something similar, didn't change the knob, or add a nut/washer on top. it was super-wedged at first, now it's slipping, I need to add a nut and washer now too. thanks the for the idea!

[jak77]

Nice write up! Looking to do exactly this once I get my setup completed. Gonna see what kind of coin holder replacement Mr Spectacular comes out with.

Good job!

[Dirt]

Nicely done!

[cspcrx]

Great job and looks great. Love the factory knob, like you said stealth but it fits the interior.

[FromRagsToS4]

Updated original post with final installation pics.

Here's what it looks like installed in the car:

[whiped]

I want to touch your knob...

No homo.

[SteveYem]

Awesome install, but I still can't reconcile the price of that little carbon piece.

[DetRebel]

Post some pics of the sub please.


Sent from my iPhone using Audizine

[cspcrx]

So yours is not one of the 3D printed units people are posting its an actual Audi coin holder that has had CF laid over the top of it right?

[FromRagsToS4]

Post some pics of the sub please.

- - - Updated - - -

So yours is not one of the 3D printed units people are posting its an actual Audi coin holder that has had CF laid over the top of it right?

Correct. To support it, the guy that made it filled the coin slots with epoxy and sanded it down to give a good surface to lay the CF down on.

[dillysd]

Stop being awesome!! Your making us look bad.


2015 S4 DSG - CTS Intake, APR Stage 1 ECU, APR TCU, APR CPS, AWE Touring, AWE Res Pipes, 034 Trans/Diff/Subframe Mounts, RS Grille, RS Fog Grilles, ECS Boost Gauge, TSW Nurburgring 19x9.5

[bguild]

I love the attention to detail in this project. Great work!

Sent from my SM-G955U1 using Audizine mobile app

[ModItNow]

Looks awesome! Nice job


Sent from my iPhone using Audizine

[ScottKC]

Great work. I have been contemplating something kind of similar for my C5 A6. Since the euro spec cars have a manual headlight range adjustment, that dial is left off the US headlight switch assy. That pot could be used for bass control and would be slick as hell. Not to mention nobody would guess what the dial is for..

Sent from my SM-G955U using Audizine mobile app

[techracer]

Does anyone know if someone sells a coin holder delete that matches the black surround trim? I am in need of one for my lc2i bass knob

Sent from my SM-G955U using Audizine mobile app

[TamasF]

hi,
II would like to make something similar you made, but I need you help...could you please take a few pictures for me from the PCB of the remote control knob? I mean the green PCB is visible from the direction of rj14 connector, but I would like to know the PCB layout, on which pin is the potentiometer connected. And I also need the value of the potentiometer in case you could help me please. Thanks in advance!

- - - Updated - - -

I felt the standard B&O sound system lacked low end. To address this, I installed Mr Spectacular's Driver side "Spec" fiberglass subwoofer enclosure for a sleek audio upgrade that didnt compromise on trunk space. Wanting bass control so as to not drive the wife and/or kids crazy, I was unsatisfied with any other location to mount the remote sub control knob besides where the coin holder is located to the right of the shifter.


Here's a pic of the final installed product:



Keeping in line with the stealth/OEM/sleek look, I decided I was going to use an OEM knob already present in the vehicle and figured the best one to use was the knob used for adjusting side mirrors. I would then have to figure out a way to retrofit the knob onto the post that the Alpine knob was pressed on to, and then figure out a way to mount the knob control pcb underneath the CF coin holder.

I purchased the CF coin holder from seller "diycarbon" on eBay, the mirror control switch button (P/N: 8K0959565F) from eBay (came out of a 2013 A4 Prestige S-Line), and the Alpine RUX-KNOB. Pictured below:






Most of my grinding I did with the dremel carving bit set 115.



Since the outer diameter of the plastic Alpine bass knob was exactly the same as the inner black plastic part of the OEM knob, I decided I would hollow out the OEM knob, cut the outside shell of the Alpine knob and keep the inside "crosshair" section intact.
Here is the OEM knob hollowed out:



I used a standard small Dremel grinding wheel to cut off the outer layer of the Alpine knob.



Here is the inner section with the outer "barrel" fully removed:



I kept trimming the side fins little by little until it fit snugly in the OEM knob (note the masking tape to keep the silver finish protected during work):



I mixed up some plastic epoxy and filled the OEM knob about 1/3 the way, then placed the Apline center fitting in, making sure to align it with the outer plastic "peak" on the OEM knob to make sure its pointing in the right direction:



Testing fitment on the post:



After taping the glossy CF with a few layers of masking tape, as well as the surface it was resting on, I used the Dremel tool (with the drill press attachment) to start hollowing out the interior of the CF coin holder so that the Alpine PCB would have the clearance to let the post through enough to use the nut to secure it:



Here is the hollowed out section inside the coin holder. Note, once I got close to the end, I was very careful to take very little off or else I would risk breaking through the other side or cause it to crack



Here it is after I got the post to stick through enough to put the washer and nut on securely:



Final product:



Got the switch installed in the car. Lots of work to relocate and run the wire!




Works like a charm!

hi,
II would like to make something similar you made, but I need you help...could you please take a few pictures for me from the PCB of the remote control knob? I mean the green PCB is visible from the direction of rj14 connector, but I would like to know the PCB layout, on which pin is the potentiometer connected. And I also need the value of the potentiometer in case you could help me please. Thanks in advance!

[apoelistas]

For radio concert a similar coin holder add on is already available with some android third party nav multimedia screens as a bundle. Comes with nav button which is the button missing from the B8 steering wheel (+ back button).

Would be interested in retrofitting this button if I can find it to my center console coin holder.

If anyone knows where I can find it as a replacement part please inform.

It is more of a different exercise since this is for making radio concert steering wheel controls or radio concert controls to be controlled also on the center console.
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