Speakers - wiring question

My car had an aftermarket stereo installed. As usual, the installer hacked
the harness, spliced the wires, and taped it up. How can I be sure the
speakers were wired in phase. The polarity on the speakers is not labelled.
The wire leads are the same colour. Is there a test you can do with a VOM
meter?

Thank you

 

The only way I can think of to do it is to follow each wire back thru
the splice to the original wire and go by color codes (or do continuity
check upstream of splices to downstream of splices to match the wires up
if, say, the splices are all bundled together and taped). Figure out
which is pos. and which neg. for each speaker from the schematic
(typically on late model Chryslers, the color of the stripe on each
left/right pair will be the same for both negatives and another same
color for both positives; additionally, most, but not all, negatives
have a black stripe; no positives have a black stripe).

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Set the radio to AM in order to receive a monophonic signal. Set the balance
control on in the middle. Play something and than reverse ONE set of speaker
leads, left or right but only one channel. If the sound gets louder that is the
correct phasing. You can temporarily wire a DPDT switch to accomplish this.



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/
Aurora, Ontario

 

Frankly, if you can't tell by listening to the stereo, it
doesn't matter.

 

That was actually going to by my question. I understand phasing, but can you
actually hear it? I don't think I can, but I never heard it would get louder.
The DPDT switch would make it easier to compare, but when I have tried
switching wires, I could not tell any improvement or degredation of the sound.
Maybe it's just my ears.

 

Check the wires carefully. If there isn't a colour stripe on them,
there usually is a raised ridge on one.

Same for the speakers, usually one of the tabs the wire plugs onto is
larger than the other.

A 9 volt battery can tell you which is plus on the speaker. You tag it
to the speaker terminals for a quick second. One way will push the
speaker cone out, the other way will suck it in. I 'think', but could
be in error that a proper plus neg tag pops the cone outward.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

 

Full deep bass means correct wiring. I connect stereos ignoring
speaker wire colors, I swap wires unitil I hear the bass on dificult
cars. On tweeters or non-bass speakers, it's difficult and doesn't
matter.
Rick
"Hearing is in the ear of the beholder."

 

Thank you for your replies. These seem like good tips. I will try them.

Sorry folks for cross posting. I'm new to this sort of stuff. I have been
criticized for posting only to 1 group and criticized for posting to
multiple groups. I guess there's a time for one and a time for many. My
timing is a little off right now. I'll fix that while I fix my speaker
wiring.

 

If this has been suggested already I apologize.
With the WIRES DISCONNECTED FROM THE RADIO: locate the negative wire that is
supposed to go to the speaker, and use a battery (AA) to check for phase.
This is done by placing the negative (ground) wire on the negative end of
the battery, and the other wire on the positive end of the battery. If done
correctly all of the speakers may be checked in turn (one at a time) to
determine that they all move in a forward direction (that is that the cone
moves outward) when connected to the battery.
Regards, Ken.