Steve and Tom, a polarity disparity

[Pinknik]

I discovered a while back that my Sound Dynamics 300ti speakers, which I like the SOUND of, have a different polarity between the midrange driver and the bass driver. I tested it with a Sheffield Lab disc and sensor made for just such a purpose, the bass has proper polarity, but the mids are the exact opposite. Is this negatively effecting the accuracy of my speakers? Is this common? Thanks.

[Humorem]

Speakers that employ 12db per octave crossovers must reverse phase on alternate drivers because the crossover reverses phase as part of its action.

It's not a good thing, all things being equal, but since all things are never equal, it's for you to decide how well it works.

And that's phase, not polarity.

TP

[Pinknik]

Egad, now I'll have to go back and study the whole thing again. When my woofer pushes, my mid driver pulls and I thought that was polarity. Anywhoo, thanks for the answer, it's back to the books for me, Dr. Tom and Professor Feather.

P.S. What's your current reference system on which you make your HIFI judgings? Thanks.

[Humorem]

You can see that happen? That can't be right. Reverse the leads to one or the other. They have to both push out at the same time or you are out of phase, baby!

There's a whole thread for my system, somewhere on here.


TP

[Pinknik]

No, I can't see it happen, but that's what appears to happen on the polarity tester. The CD that comes with it has a series of pulses, like push, push, pull signals. They occur in a specific order so you can tell if your speaker gets them backwards (pull, pull, push) then you know polarity is backwards. Thing is, when I am playing the track, if I have the sensor close in front of the speaker, the woofer goes push, push, pull while the midrange goes pull, pull, push. Perhaps I'm misinterpreting the findings. Anyone familiar with this polarity tester?

[Humorem]

There is a very easy way to test this by ear.

Disconnect all drivers but two.

Play some music. Now rewire one of the drivers. Is the sound better or worse. If it's better you have out of phase problems.

Proceed with all the drivers until they all sound best the way they are hooked up.

Testers, smesters. Use your ears.

TP

[Gary]

There's always the trusty 9 volt battery test - but you have to take your speakers apart to do it.

Worked for me, at least! :)

[Humorem]

For mids and tweets you sometimes can't see them move with a battery so that isn't always the answer.
TP