Determining wire phase


I’m re-routing the subwoofer speaker wires from my built-in Bash plate amp (recently died) to an external Dayton Audio SA1000 sub amp.  The wires in my subwoofer are yellow and white.  I’m trying to figure out which lead is the positive, which is the negative.   Attached is a picture.   FWIW, the white lead is located at the bottom of the Bash plate amp.  Is there any way to determine which is which with my multimeter?   There are no markings on the circuit board.  Thx.

Bash sub plate amp.jpg

 

 

steakster

The wires in my subwoofer are yellow and white. I’m trying to figure out which lead is the positive, which is the negative.

@steakster

As for the woofer speaker polarity:

Use a 1.5Vdc C or a D cell battery. Press either one the two wires on the negative end of the battery. While looking at the woofer cone momentarily touch the other wire to the positive end of the battery. If the speaker cone moves outward the polarity is correct. If the cone sucks back the polarity is reversed.

You want the cone to move forward for positive polarity.