# The Bose Amp



## Audi Russ (Feb 29, 2020)

Afternoon all,

Was looking forward to installing my new Kenwood head unit this morning, only took me four hours and a few scrapped knuckles with all the GPS, DAB, Microphone etc...

Powered it up, all good but no sound. Then realised I'd not connected the RCA cables, still no sound. Sadly researched it and it appears my Bose amp is one of the later ones which requires the Can Bus to turn it on, not just the little blue wire :?

There doesn't appear to be loads of fix's or options for this, I definitely need the new unit. Does anyone know of a fix or if it's possible to change the Bose amp for something that will work?

Thanks in advance,

Russ


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## Knight-tts (Jan 29, 2019)

I've never heard of that problem before I thought all Bose amps were all the same


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## John949 (Apr 12, 2017)

It is possible to generate the required CAN signals using say an Arduino and a CAN shield, but if you've never done any programming before it might be a bridge too far. Have you contacted Connects 2? As they make units that interface between the steering wheel CAN system and the analogue controls on third party head units, they may have made a unit that also generates the CAN signals for the Bose. Failing that, then your best option might be to get hold of an earlier Bose amp. The Bose amp uses low impedance speakers so if you go for a different amp then you would probaby need to change the speakers as well.

Another long shot would be to swap the head unt for an Xtrons one. I believe these can generate the required CAN signals but you have to set it to different vehicle so the steering wheel controls don't work (unless they've fixed it for the Latest models).


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## John949 (Apr 12, 2017)

> I've never heard of that problem before I thought all Bose amps were all the same


Don't know for sure but:

According to the wiring diagram, the Bose (J525 - Digital Sound Control Module) is connected to the infotainment bus. There have been several posts from people who couldn't get sound after installing an Xtrons with a Bose but cured it by setting the CAN settings to a different car. This is consistent with what the OP is saying.


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## Audi Russ (Feb 29, 2020)

Thanks John.

I've messaged the car audio place when I bought the unit from and see what they say. Good idea about contacting connects 2. It's all such a pain....

I think replacing the amp with an older Bose is probably the best way forward.

Thanks for your help


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## barry_m2 (Jun 29, 2015)

You just need to find someone local with vag-com to change how the amp is switched. Takes 10 seconds.


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## Audi Russ (Feb 29, 2020)

I'd heard that something needed to be changed with VAG but also that some wiring needed to be done too?


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## Hammer'd (Feb 21, 2020)

John949 said:


> Another long shot would be to swap the head unt for an Xtrons one. I believe these can generate the required CAN signals but you have to set it to different vehicle so the steering wheel controls don't work (unless they've fixed it for the Latest models).


Latest models are all plug & play. You don't need anything extra at all. However I believe that unless you get an Xtrons from Ebay or Amazon, you might have to wait as there aren't any units on the main Xtrons site. Possible that they're bringing out a new HU soon.


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## Audi Russ (Feb 29, 2020)

I emailed a company last night who repair and exchange the TT bose amp, they said that the Can Bus DOES NOT control the amp turn on, it's only used for diagnostics;

"Hi Russell

None of the Bose units are controlled by canbus .. this is only for diagnostics ... the issue will be the remote trigger ' on ' wire .... if you go to our support page .. password is library - there is a wiring diagram for the amp ... check you have a 12v trigger to pin 29."

I guess these guys are the Bose experts? Will look into this pin 29 more and see how I get on.


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## barry_m2 (Jun 29, 2015)

The bose amp will need recoding from a digital to analogue signal to turn it on, I know this becase I've done it on a fellow members car who fiited a Pioneer HU to his Bose system. As soon as I made the change, with VAGCOM, it powered up straight away.

You might also need to change a wire too, I didn't do that bit for him.


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## Audi Russ (Feb 29, 2020)

Thanks all.

Yes the VAGCOM change is becoming more and more apparent. The different ideas you have from different sources is quite funny.

I have a mobile technician coming out to my work tomorrow for £60 who says he can fix it. Fingers crossed!


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## Audi Russ (Feb 29, 2020)

UPDATE - FIXED!!!!

I had the mobile technician visit today, he's not come across this problem before but re-programmed the Can Bus settings to the Bose amp and it now switches on! Best £60 I've spent (well nearly...) I think. So pleased this was all I needed to do.

Just need to dry the carpet out now and hopefully that will be me up and running!


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## ADB (May 7, 2002)

Audi Russ said:


> UPDATE - FIXED!!!!
> 
> I had the mobile technician visit today, he's not come across this problem before but re-programmed the Can Bus settings to the Bose amp and it now switches on! Best £60 I've spent (well nearly...) I think. So pleased this was all I needed to do.
> 
> Just need to dry the carpet out now and hopefully that will be me up and running!


https://www.totalcardiagnostics.com/sho ... stech-vcds

£56 including postage...


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## John949 (Apr 12, 2017)

I know my Xtrons uses the CAN Bus to switch on and off because it won't power up on the bench without the CAN bus signal. Also if you turn the key fully off but leave it in the ignition, the unit stays powered; so it is using the 'Key out' signal (2C3 10) on the CAN Bus to turn off, as opposed to the 'Ign off' signal (2C3 11) Does the CAN switched Bose behave the same? Is this a way to tell them apart? Note that I'm talking about the amp not the head unit. My old BNS switches off with the IGN off, don't know what RNS or Chorus do.


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## barry_m2 (Jun 29, 2015)

Audi Russ said:


> UPDATE - FIXED!!!!
> 
> I had the mobile technician visit today, he's not come across this problem before but re-programmed the Can Bus settings to the Bose amp and it now switches on! Best £60 I've spent (well nearly...) I think. So pleased this was all I needed to do.
> 
> Just need to dry the carpet out now and hopefully that will be me up and running!


Told ya 

Next time, if you need something doing, post up your location as there may be someone local with VAGCOM that will do it free for you.


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## Audi Russ (Feb 29, 2020)

Cheers Barry, will do!


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## polymoog (Mar 14, 2020)

Audi Russ said:


> UPDATE - FIXED!!!!
> 
> I had the mobile technician visit today, he's not come across this problem before but re-programmed the Can Bus settings to the Bose amp and it now switches on! Best £60 I've spent (well nearly...) I think. So pleased this was all I needed to do.


Hi there,

I have also just installed a Kenwood head unit, had it done by an audio place. Also have Bose system. Do you experience any difference in sound quality? Have been reading that there can be problems if you just change the HU and still have the Bose amp and speakers? My sounds is now much worse, from all sources ... Have changed lots of diff EQ settings/profiles in Kenwood unit and sound still worse than before ... Saw that you also had Bose system so would be interested to hear what you think. My Kenwood model is DPX-5100BT.


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## TTsdsgomg (Mar 19, 2013)

barry_m2 said:


> Audi Russ said:
> 
> 
> > UPDATE - FIXED!!!!
> ...


Do you guys know what the actual coding changes are ? [smiley=book2.gif]


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## Audi Russ (Feb 29, 2020)

Hi Polymoog,

Yes I just saw your earlier post. I actually went for a long run today and was thinking how good it sounded for an old car (sorry this doesn't help you at the moment...). I was going to go for an Alpine unit as I rate them highly but the cheapest one I could find was £500 so went with the Kenwood around £350. Mine is the DMX717 I think.

Apart from the amp not turning on at first it all went fairly smoothly with no problems. I would guess that there's a problem somewhere else rather than the head unit? It should improve the sound if anything. Have you tried another wiring harness? The RCA cables all look good and connected well?

I think the technician said he'd change canbus code to send an analogue signal to the amp to turn it on rather than a digital one?


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## MT-V6 (Jan 11, 2015)

I am assuming 0xxx?xx was changed


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## Audi Russ (Feb 29, 2020)

Erm.... Probably.... :roll:


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## TTsdsgomg (Mar 19, 2013)

MT-V6 said:


> I am assuming 0xxx?xx was changed
> 
> View attachment 1


MT-V6 do you know which is standard audi bose 1 or 2


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## polymoog (Mar 14, 2020)

Hi Russ,

Thanks for your reply!

OK interesting. I think my model is probably a bit more of a budget option, cost 1500 SEK which is around £120. Had it installed by an car audio place so do not know how they wired it. However I could ask them re what signal they had set to be sent to amp, thanks for the tip.

Played around a bit more this eve and changed speaker sizes in the Kenwood settings which helped a bit, but sounds still sounds "canned" and bass not brilliant. Did however get tweeters to give a more balanced sound.

Are your speakers original? Was thinking that after 13 years, mine might be a bit worse for wear, don't really know the life expectancy of speakers TBH?

Katrina


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## Audi Russ (Feb 29, 2020)

Hi,

The only reason you'd need to ask about the signal to the amp is to switch it on, if your amp is on (which it obviously is) I don't think there's anything they can do with VagCom?

If it sounded fine before you changed the unit then your speakers must be fine. I'd take it back to the installers and perhaps ask then to try another head unit first? If no different then then the wiring they used?

I'm wondering, is there a setting on the head unit with regards to the volume/signal coming out of the RCA's?


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## MT-V6 (Jan 11, 2015)

TTsdsgomg said:


> MT-V6 said:
> 
> 
> > I am assuming 0xxx?xx was changed
> ...


1


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## polymoog (Mar 14, 2020)

Audi Russ said:


> Hi,
> 
> The only reason you'd need to ask about the signal to the amp is to switch it on, if your amp is on (which it obviously is) I don't think there's anything they can do with VagCom?
> 
> ...


Sorry missread you first reply re amp signal ....

Sound was not fantastic with original HU but did not expect it to be worse after installing the Kenwood. Obviously some limitations due to sound source, MP3 not going to sound like original CD, but even CD's do not sound quite the same as before ... However just seems like the speakers in the Seat handle crappy MP3 much better than mine, perhaps because they are newer.

Will check settings again re signal coming from RCA's. [smiley=book2.gif] Thanks for your help!


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## SwissJetPilot (Apr 27, 2014)

Is the code change done under Address 47-Sound System, Address 56-Radio or somewhere else?

Also, it might be cheaper to make the code changes yourself with an OBDeleven rather than the expense of buying a VCDS just for this modification.

@ ADB - Would you happen to have a scan of your VCDS so we can see your codes for these two addresses? That way we can probably figure out exactly what they changed.


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## ADB (May 7, 2002)

SwissJetPilot said:


> Is the code change done under Address 47-Sound System, Address 56-Radio or somewhere else?
> 
> Also, it might be cheaper to make the code changes yourself with an OBDeleven rather than the expense of buying a VCDS just for this modification.
> 
> @ ADB - Would you happen to have a scan of your VCDS so we can see your codes for these two addresses? That way we can probably figure out exactly what they changed.


The coding on mine is 0236117 - so its 1 - Activation via Remote Wire

My car originally came with the Symphony head unit and Bose, however the Symphony was replaced with a RNS-E at some point and no coding was done. The coding was corrected (comfort?) so contacts via the BT phoneprep could be accessed on the RNS-E, however I now have a Xtrons (MTCD-GS) unit installed.


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## SwissJetPilot (Apr 27, 2014)

This should easy enough to re-code with an OBDeleven looking at my own - Sound System 47:


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## TTsdsgomg (Mar 19, 2013)

MT-V6 said:


> TTsdsgomg said:
> 
> 
> > MT-V6 said:
> ...


Mt-V6 there may be a twist to that info as when I read my amp details it was 3  which apparently is only read by a later gen factory rns-=e :?


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