[Castanza]

on speakers. When I recently had someone fish wires down a insulated wall for my rear speakers, the fellow downstairs near the receiver used a d cell battery. I feel sure he was testing which is + & -, am I correct? If so, how can you test, that is if you touch the wire to positive & it is positive how will you know? Also he used the insulated fire retardant wire that is used in attics, and so on.

[jonwb]

If so, how can you test, that is if you touch the wire to positive & it is positive how will you know?

If you touch the wires to the battery and the cone moves outward then the wire on the + end of the battery is + and the wire on the - side is - (polarity correct).  If the cone goes inward then its the opposite of what you are doing (incorrect).  

Now checking the polarity on a individual dome or ribbon tweeter, that's a trick I'd like to learn...

good luck

[karthikn]

The battery thing test, I would be wary of.  From what I know, DC is not really good for the speakers.

Does it really matter whether you have the leads matched (black->black and red->red) ?  It might be my ears, but I have not heard any difference in sound.  What matters is that you have them connected the same way with both speakers.  Correct ?

[jonwb]

The battery thing test, I would be wary of.  From what I know, DC is not really good for the speakers.

I've always just used a AA battery.  Doesn't seem to bother the speaker any.  The cone moves very little, you have to have your face right next to it to see how its moving.

Does it really matter whether you have the leads matched (black->black and red->red) ?  It might be my ears, but I have not heard any difference in sound.  What matters is that you have them connected the same way with both speakers.  Correct ?

If you don't have them hooked up correctly (per the design intent of the speaker maker) they will be out of phase and sound funny.  There is acutally a check for correct speaker connection polarity in some THX Optimizer selections on certain DVD's.  You can always swap your connections and give it a try, but the will likely sound different.

[nathanm]

As I understand it there's polarity and absolute polarity.  If you have one speaker wired opposite of the other you'll hear that weird phasey sound, but absolute polarity refers to a positive swing of the waveform creating a positive voltage on the speaker, thus moving the cone forward and then back, not the opposite.  This might be much harder to hear, meaning your wires were connected opposite to the speaker.  Stan Ricker is big on this.  Look him up sometime, pretty interesting fellow.

[markC]

One realatively easy way to check standard speaker polarity is to have your two speaks facing each other at about 6 " apart play some music with a decent bass line and note the amount of bass heard. Now reverse the leads on ONE speak and play the same cut. With the speaks in phase, the bass should sound much more dominant than when out of phase. Also you will not hurt anything by doing this. With the speaks playing out of phase, the bass drivers will cancell each other, (one moving forward at the same time the other is moving back).

[randytsuch]

Wanted to add one thing.  Sounds like these are the rear speakers in a multichannel setup?  If so, they not only need to be in phase with each other, but also with the front and center channels or things probably won't sound optimal.
I have heard of that battery test before.  DC is not good for speakers, but I would not think 1.5 volts for a second to check polarity would hurt them.

Randy

[PJ]

DC wont hurt your speakers for the sake of this test..at all.

A 9V battery will draw just over 1A through an 8ohm load. You will drain the battery very quickly, but definately wont hurt your speakers.

Speakers will pulse when the experience a DC step input, but will instantly settle back to their middle position.

[andyr]

Guys (and Gals, if there are any out there!!),

There are two different "polarities" which are important in sound reproduction.  It doesn't matter whether you are talking about, say, the 3 drivers which comprise each channel of my Maggie IIIas or right channel vs. left channel:

#1 is RELATIVE polarity:

Correct relative polarity - ie. "relative phase" - means two things:

1.  The '+' (red) speaker terminal on the amplifier needs to be connected to the '+' connector on EACH driver of your speakers.

If you have a simple speaker system with just one pair of binding posts for each speaker then this is a pretty simple colour match ... as long as the drivers inside the speaker cabinet are connected right!!  Ya just have to trust this is the case!!

If your speaker crossover  has a separate pair of binding posts for each driver then you just have to make sure the '+' (red) amplifier terminal is connected to the '+' (red) terminal of EACH driver.

If you have done this correctly, then each driver in a side is working in synch with the others in that side.

2.  The R speaker has to be connected the same way as the L speaker - ie. red speaker terminals connected to the red terminals of the amplifier.

If you do this correctly then R and L channel are "in phase" with each other.

This means that you are "90% correct" in terms of "phase" or "polarity".  It may not be absolutely perfect but it will sound good!  Each channel is completely "in phase".

To get "100% correct", you need also to have the following:


#2 is ABSOLUTE polarity:

This is a much more subtle effect.  Think of it in this way:
*  if a singer blows into a microphone, the microphone diaphragm bends away from the singer's breath.
*  this should correspond to the speaker cone moving outwards (towards you) ... to project the singer's breath into your ear!!

It could be that all your speaker cables are reverse-connected to the speakers (it's easier to envisage this if you just have speakers where each have a single pair of binding posts).

IE. when the singer is actually blowing, the cone is going backwards so it comes out of the speaker as a "suck".

You therefore need to experiment with reversing ALL the speaker cable connections, to see whether this improves what you are listening to or not.

Percussive transients like cymbals, piano or wood blocks will sound "more natural" if you have correct absolute phase.

Happy listening,

Andy