[s-cars] Bose system pops with Alpine deck

[Andrew Beckert]

Sorry eric, my response was directed at the threadstarter, I forgot to  
add the footnote for trafficpro users. The trafficpro is one of the  
few units to use a common ground (I believe it has no internal amp).   
I have no direct experience with it, but it *should* work out of the  
box.  Your problem is an issue with how the Bose amp power on/off  
mechanism was wired into your trafficpro, as opposed to  general  
ground potential differential issue. Sound like the traffic pro was  
shutting down without switching the Bose amps off.  How did you wire  
the amp trigger?

Andrew

Sent from my iPod Touch

On May 1, 2008, at 2:19 AM, "Eric Phillips" <gcmschemist at gmail.com>  
wrote:

> Well, that was one of the first links I found when I was searching.
> GLIs didn't work for me.  Nor did running grounds, including the
> common ground designated by the Traffic Pro, directly to the negative
> terminal of the battery.  I did EVERYTHING I could to minimize the
> amount spent to make this "cheap" headunit work.  (Cheap because the
> guy was getting rid of it - "it doesn't work" he says.  LOL.  Works
> great for me!)  In the end, I spent quite a bit of time, and coin,
> making the speakers not pop.  I swear that I tried every solution I
> could find in the archives here, in Audiworld, at Crutchfield, on the
> web in general...
>
> And the very strangest thing is that some of those other solutions
> worked for some other UrS owners.  Line level outputs directly to
> amps?  Worked for two other guys with UrS cars that have Traffic Pro
> retrofits.  GLIs?  Worked for guys on the C4 forum in Audiworld with
> aftermarket head units.  Speaker->line level converters?  Pooh-poohed
> by many, but they worked for several A4 owners.
>
> I think you have to go with whatever works, and that there is no *one*
> solution that works for all Bose installs, short of radical
> Bose-ectomy.
>
> Eric
>
> On Wed, Apr 30, 2008 at 9:55 PM, Andrew Beckert <abeckert at gmail.com>  
> wrote:
>> You need to run your line-outs through ground loop isolators into  
>> the Metra
>> harness.  Most aftermarket stereos use floating grounds as they have
>> individual amps for each speaker.  The Audi/Bose is designed to use  
>> a common
>> ground, so whenever you change tracks or turn your new HU on, the  
>> audio
>> would be grounded using the common ground, but with the aftermarket  
>> unit a
>> floating ground is used with a potential differential from common  
>> ground
>> (what the Bose amps are using for power), and this causes the  
>> capacitors in
>> the Bose amps to discharge creating that cool popping sound.  At  
>> least
>> that's how it was explained to me.  Here's a Crutchfield link that  
>> goes into
>> some more detail:
>>
>> http://www.crutchfield.com/S-MbhgVdg05NA/tech/kb350.html
>>
>> ymmv,
>> Andrew
>>
>>
>>
>> On Thu, May 1, 2008 at 12:30 AM, <calvinlc at earthlink.net> wrote:
>>
>>>
>>>
>>>
>>> That is a GREAT way to describe it!  The tumor in my car known as
>>> Bose.....That's great!
>>> --Calvin
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Eric Phillips [mailto:gcmschemist at gmail.com]
>>> Sent: Wednesday, April 30, 2008 10:05 PM
>>> To: calvinlc at earthlink.net
>>>
>>>
>>>
>>>
>>>
>>>
>>> Cc: john at johncleirigh.com; s-car-list at audifans.com
>>> Subject: Re: [s-cars] Bose system pops with Alpine deck
>>>
>>>
>>> Here's a funny story:
>>>
>>> When I first got my Traffic Pro, I used its line-outs to go to the
>>> Bose stuff.  Popping on shut-down, just like the OEM head unit.  I
>>> tried capacitors in-line.  Nope.  Noise suppressors.  No dice.
>>>
>>> So, I purchased a line level converter.  Well, it goes both ways -
>>> line-out to speaker level, and speaker level to line-out,  
>>> depending on
>>> what way you hook it up.
>>>
>>> I used the speaker outputs on the Traffic Pro as my "in" and line
>>> level as my "out" - no popping.
>>>
>>> The Bose crap is weird.  Maybe some day, I'll do some surgery and
>>> completely remove the tumor in my car known as "Bose".
>>>
>>> Eric
>>>
>>> On Wed, Apr 30, 2008 at 8:44 PM,  <calvinlc at earthlink.net> wrote:
>>>> Eric,
>>>>
>>>> I am feeding the Bose system with the Line-Outs from the Alpine  
>>>> and it
>>> does
>>>> NOT eliminate the popping.
>>>>
>>>> --Calvin
>>>>
>>>>
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: s-car-list-bounces at audifans.com
>>>> [mailto:s-car-list-bounces at audifans.com]On Behalf Of john cléirigh
>>>> Sent: Wednesday, April 30, 2008 6:30 PM
>>>> To: Eric Phillips
>>>> Cc: s-car-list at audifans.com
>>>> Subject: Re: [s-cars] Bose system pops with Alpine deck
>>>>
>>>>
>>>> Indeed Calvin and Eric!  You're both right about my response.  I  
>>>> should
>>>> have offered my experience as a data point to suggest the remote  
>>>> amps
>> are
>>>> registering the power-down as a thunk through the speakers and so  
>>>> any
>>>> aftermarket head unit with a non-filtered (non-balun'd) output will
>>> likely
>>>> also overload the front end of the amps.  Thanks.
>>>>
>>>> I think the Alpine deck should feed the Bose amps from the RCA  
>>>> jacks
>> and
>>>> not the speaker harness.  I'm sure that would eliminate the thunk
>> because
>>>> the amps are looking for a line level input.
>>>> --
>>>> john cléirigh | Boulder
>>>>
>>>> On Thu, May 1, 2008 12:11 am, Eric Phillips wrote:
>>>>>> The worn rotary switch and the amps popping or thumping are two
>>>>>> separate issues, IMO.
>>>>>>
>>>>>> I, too, had the thumping on DeltaCC power-off (only with rotary  
>>>>>> knob
>> -
>>>>>> the ignition wasn't in the circuit.)
>>>>>>
>>>>>> Then I put in my Traffic Pro, and lo and behold - same problem on
>>>>>> powerdown.  OK, so then I put a device in-line - a speaker ->  
>>>>>> line
>> out
>>>>>> converter.  No more popping.  :)
>>>>>>
>>>>>> I am very happy with the way it all turned out.  I would have
>>>>>> preferred to stick with Audi stuff - like a Concert I as the head
>> unit
>>>>>> - to avoid all the electrical gymnastics it took to make the  
>>>>>> Traffic
>>>>>> Pro work.
>>>>>>
>>>>>> Eric