testing speaker wires

[p8ntblr]

Just finished running some speaker wires for the entertainment center. Since I don't have the entertainment center yet (being shipped), what's the best way to test the wires weren't damaged when I was fishing it through the walls. I was thinking of checking continuity with a fluke meter. yes ? no?

[eezlock]

testing speaker wires

The best way is to test for continuity with an ohm meter. eezlock

[LCHIEN]

here's the best procedure:
First you have to check and make sure they are not shorted to each other
At each end, check with an ohmeter and see that its open ("OL")
Then, if you know they are not shorted, twist one end together
and check the continuity at the other end - the pair should now have nearly zero ohms because the are shorted at the opposite end. One or two is probably OK depending upon the size wire and length.
This technique solves several problems including how to measure end-to-end continuity when they are far apart.

P.S. don't forget to untwist the ends after testing - could blow up your amplifier if you leave it like that!

[tedkitch]

I've always wondered about this, how do you know which wire is the + and which is the negative if the wires weren't labeled. In the last house that I lived in there were some pre-run wires that weren't marked. After putting speakers at the end (the amp that powered the speakers came with the house) I could plug the wires in either way and the music didn't sound all that weird.

How can you tell? Is there something that you could listen to that would make it so evident?

[big tim]

I've always wondered about this, how do you know which wire is the + and which is the negative if the wires weren't labeled. In the last house that I lived in there were some pre-run wires that weren't marked. After putting speakers at the end (the amp that powered the speakers came with the house) I could plug the wires in either way and the music didn't sound all that weird.

How can you tell? Is there something that you could listen to that would make it so evident?

Here is one way of checking unmarked wires, providing you have an Ohmmeter (or Multimeter):
Disconnect the wires at the speaker and amplifier.
Twist the conductors of one of the pairs together at the amplifier as well as at the speaker end.
Connect one of the conductors of the other pair at the amplifier end to the pair of conductors you just twisted together.
At the speaker end connect one testlead to the twisted together pair and take the other testlead to look for continuity with one of the conductors in the other pair.
Once you have continuity, mark that conductor at both ends with a piece of tape for instance.
Now go through the same procedure with the other pair. In fact you don't have to twist the other pair together because you have allready identified the individual conductor in that pair.
And as mentioned before, don't forget to untwist before putting things back in service.
Good luck

Tim

[wbsettle]

The easiest way, IMO, to identify speaker wire polarity is with a 9v battery. Disconnect the connections from your amplifier end. Touch the leads to the +/- terminals of a 9v battery while observing the woofer of the attached speaker. If you're matching amp(battery) + to speaker +, the cone will move outward from the cabinet. If you've matched - to speaker +, the cone will be "sucked" inward. Once you've determined postive/negative, mark for future reference with a Sharpie.

I'd be surprised if pre-run speaker wire wasn't labeled, but it may be hard to see. In the absence of a polarity stripe, there's likely an embedded label about every foot on one of the conductor pair. Since it's embedded in the jacket, it's really hard to see.

-Brent

[Holbren]

The easiest way, IMO, to identify speaker wire polarity is with a 9v battery. Disconnect the connections from your amplifier end. Touch the leads to the +/- terminals of a 9v battery while observing the woofer of the attached speaker. If you're matching amp(battery) + to speaker +, the cone will move outward from the cabinet. If you've matched - to speaker +, the cone will be "sucked" inward. Once you've determined postive/negative, mark for future reference with a Sharpie.

I'd be surprised if pre-run speaker wire wasn't labeled, but it may be hard to see. In the absence of a polarity stripe, there's likely an embedded label about every foot on one of the conductor pair. Since it's embedded in the jacket, it's really hard to see.

-Brent

Was in the audio business for 10 years, that's what we did. I wouldn't hold the battery there too long though.

[LCHIEN]

I've always wondered about this, how do you know which wire is the + and which is the negative if the wires weren't labeled. In the last house that I lived in there were some pre-run wires that weren't marked. After putting speakers at the end (the amp that powered the speakers came with the house) I could plug the wires in either way and the music didn't sound all that weird.

How can you tell? Is there something that you could listen to that would make it so evident?

Virtually all zip-cord/lamp cord I've evere seen is marked so you could identify the wires... sometimes its not obvious.
The clear stuff is gold/silver conductors.
The opaque stuff, usually has a rib (single) molded to one conductor or multiple ribs.. they're usually subtle, you have to look closely; you might not see them from two feet away.

FInally a person with a good ear can hear the phase issues. If both speakers are out of phase, it will sound pretty much normal altho in the speakers will pull instead of pushing, most people can't tell that.

When out of phase, the most affected are bass signals which have long wavelengths and will cancle out some (one pushing, one pulling) when playing mono or stereo because most bass is pretty much the same in R & L channels. The standard phasing test is to play bass heavy material and switch the wires at one speaker , repeat and leave the seup that sounds most bassy.

Nowadays, my home theater amplifer has a microphone and a computer and it will play a signal into one channel (of 7) at a time and tell me when it finds one out of phase. It worked! (DAMHIKT)