[s-cars] Bose head unit notes

Mark Strangways Strangconst at rogers.com
Mon Jul 19 22:34:55 EDT 2004

Actually that is fairly low level.
A lot of high end components now seem to be 5 volt or even 10 volt.
Makes noise a thing of the past.

  ----- Original Message ----- 
  From: Kevin Day 
  To: s-car-list at audifans.com 
  Sent: Monday, July 19, 2004 10:11 PM
  Subject: [s-cars] Bose head unit notes

  There seemed to be a bit of confusion in the archives as to whether the
  stock Bose (Blaupunkt) head unit can be mated to aftermarket amps and 

  For the record, the Audi/Bose Gamma CC unit in the Ur-S4 has fairly
  standard (for car audio) line-level outputs.  I measured 1.8 Vrms 
  maximum at the input to the rear amplifier.  For the measurement I
  burned a 1 kHz sine wave at 0 dBfs onto a CD and turned the volume 
  all the way up with the speakers disconnected.  Tone controls were flat.

  I do not believe that the head unit is doing any equalization of the
  signal.  I have it on good authority that the EQ in Bose systems of this
  vintage is done in the amplifiers, using good old fashioned RLC circuits.  
  A visual inspection of the amp PCBs seems to confirm this.  (There are 3
  different amp part numbers, incidentally: LF RF and rear.)

  In any event, after confirming that the output was normal 
  I hooked up an aftermarket amp and a new pair of 6x9s in the back.  It
  sounds pretty good, considering I haven't done the front yet.  

  Anyone have words of wisdom to share regarding wiring up the front 
  speakers to an amp in the trunk?  Wiring routes?  

  '94 S4

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