Hello,

I connect +/- signal from my head unit to the amp's high input wires L/R +/-
but the sound quality is not acceptable (as well as when I set the balance
to left/right BOTH of the speakers connected to the amp are still playing).
There is another, fifth wire in the high input section labeled as "signal
grnd". When I connect it to the chassis ground the sound is good but: 1) I
do not know WHY it helps 2) Naturally I get the alternator whine noise (I
understand that "signal grnd" doesn't mean "ground" ). Anyone can help?

thanks in advance,
Luk

"Luk" wrote in message

I connect +/- signal from my head unit to the amp's high input wires L/R
+/-
but the sound quality is not acceptable (as well as when I set the balance
to left/right BOTH of the speakers connected to the amp are still
playing).
There is another, fifth wire in the high input section labeled as "signal
grnd". When I connect it to the chassis ground the sound is good but: 1) I
do not know WHY it helps 2) Naturally I get the alternator whine noise (I
understand that "signal grnd" doesn't mean "ground" ). Anyone can help?

What kind of amp are you using? Speakers? and So on.
Is the amp set to 'Bridged' mode? Check your speaker wiring , + to + , -
to -. Sounds silly but easy to overlook.