Grounding radio to avoid popping at power-on:

[Preston Brown <pbrown@econ.yale.edu>]

Popping noise saga continues:

My power matching converter from crutchfield (similar to the bose one I
think, but older and for the old Audi boosters they installed in 5000's)
said to hook the negative leads from the speakers to the negative leads of
the box, and then the negative leads coming out of the other side of the
box to the chassis of the radio.  On a "normal" setup, I was used to
connecting positive leads of the radio to positive leads of the speakers,
and negative leads of the speakers to negative leads of the radio.  There
are only 6 leads on the radio though -- 4 positive, 2 negative (negative
shared by front and rear pairs).  In the "box" wiring diagram, it asks you
to tape off all negative leads from the radio, and ground the negative
leads of the box to the radio chassis (like I did).  But for me, I only
needed the box for the REAR speakers -- the front doesn't need line level,
it needs amplified.  So I used the two negative radio leads for the
speakers.  Here's a quick diagram: 


RF = right front
LF = left front
LR = left rear
RR = right rear

	|R|
	|A|RF+ ------------------SPEAKER
	|D|LF+ ---------------------|------SPEAKER
	|I|L-  ---------------------+         |
	|O|R-  -------------------------------+
	| |LR+---+
  BLACK	| |RR+-+ | 
 ---GND-| |    | |
	| |    | |
        ---    | |
GNDED TO |     | |                       |---- RF+|P    |
RADIO    |     | |             TAPED OFF |---- RF-|O    |
CHASSIS  |     | |                       |---- LF+|W M  |
         |     | |                       |---- LF-|E A  |
         |     | +---------------------------- LR+|R T  |------AMP+SPEAKER-+
         +------------------------------------ LR-|  C B|------------------+
         |     +------------------------------ RR+|  H O|------AMP+SPEAKER
         +------------------------------------ RR-|    X|--------------+


I hope that this diagram is able to explain everything.  If anyone can 
tell what's wrong with this picture, please HELP!  The little blurb on 
the crutchfield install. sheet says that the diagram is for a head unit 
with a FLOATING ground (4 negative leads).  I think I have a COMMON gnd 
unit (2 negative leads only).  Thus should I disregard instructions to 
connect negative leads to the chassis of the radio and instead wire in 
the LR-, RR- from the box to the L- and R- of the radio?  Makes sense to 
me...but just following directions (sorta). :)

--
Preston Brown
  preston.brown@yale.edu