Added the bang and olufsen sub to the standard sound system


Registered User
Hi all,

I am looking to add a B&O sub to my 2013 A3. Planning on using the same method using a quad lock extension so that I do not need to cut any wires. I already have an amp from my old beamer which does not require a remote turn on lead, Could anyone tell me how to get a power from the battery to the Amp. I'm going to have a look this weekend to see if the amp will fit under the passenger seat.


Any progress on this?

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Registered User
The amp will go under the passenger seat. I'll need to source a quadlock extension cable and a B&O sub. In no rush at the minute.

Daniel Piccoli

Registered User
The mod is complete.

I removed the mmi unit and glovebox to gain access to the wiring and tapped into the rear left and right channels and a 12v supply behind the fusebox and run the wiring through to the boot.

Connected the high level inputs to a 200w jbl amp which fits nicely at the side of the spare wheel. Tapped into the accessory socket live in the boot which is ignition live to turn the amp on and off and then ran the wires from the amp to the dual coil B&O sub. Also had to get the longer nut and bolt that holds the spare down as the standard one is too short to hold the sub down.

why not tapping into the wires on the rear doors, this would avoid you the trouble of taking your glove compartment apart... after all, it is the same wire behind the MMI unit reaching the door of the car to power the speakers, wouldn't taping in there work the same way??

on a different question, you´re running B&O's 2 x 8ohm coils in paralell setup (4 ohm) to match the 4 Ohm bridge mode output of your GXA602 amp, correct?

I really liked what you did... i want to enhance my 2016 a3 sedan bass a little, is this project idea is simple and yet effective.


Registered User
yeh I have connected 'a s s' sub to the sub pin using quadlock pins in the back of the headunit. and it works perfect, just cant enable sub control but im not that bothered as it sound pretty good atm. :) I didn't have to pull the glove box off or anything. just the door trims. then ran speaker wire from headunit to the boot. all with the help of Rajeevx5 :D. but deffo my tech pack headunit can handle it with ease :D

Appreciate this post is three years old.....

Does the tech pack have a different head unit to the non-tech?

I have the basic setup and looking at whether I can power the *** sub off the head unit or if I should get the b&o sub with an amp.

I read they are same subs but different number of coils. I have 64 plate and vcds so hopefully I can activate the pins.


Registered User
What i did was enable the subwoofer channel on the mmi using vcds and wired that channel to my amp and then subwoofer. if you want i could help you with this as this changes the factory eq to a system with a subwoofer and adds a subwoofer control in the sound settings. I wouldn't advise tapping off the rear channels as this may damage your onboard mmi amp eventually due to a decrease in impedance (resistance) as you wired it in paralel, which increases the operating temperature of the mmi unit. What I did to avoid this is directly connect the channels to the amplifier and effectively "half amplified" the system by amplifying the front speakers and amplyifing the subwoofer channel directly. High level inputs are usually designed to be connected to directly not connected paralell of an existing channel. In your case what i would do as you already have a 2 channel sub, is activate the subwoofer channel on your mmi unit and wire the amp to the subwoofer channel. This would prevent any damage to your mmi system as you are making a direct connection between the high level input and mmi
well explained


Registered User
I did it. From standard panasonic 8 speaker sound system,retrofit to bang and olufsen system. Very very happy with sound and complete system. Feel free to ask.

How is B&O upgrade?
Does it make a drastic difference from standard?

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James Blackbrough

New Member
It's my birthday