Loudspeaker polarity checker

[Rembulan]

Hello everybody,
In multi speaker situation sometimes we can made a mistake to place a loudspeaker wire. I have seen some people use a pulse based polarity checker system but I have search around without a result. any body have idea how to build this checker ?

[Nordic]

How about a low voltage low current source like a watch battery connected between the terminals, then note if the cone moves forward or backwards?

[djQUAN]

Originally posted by Nordic
How about a low voltage low current source like a watch battery connected between the terminals, then note if the cone moves forward or backwards?

I use a 1.5V or 9V battery.

[Rembulan]

How about a low voltage low current source like a watch battery connected between the terminals, then note if the cone moves forward or backwards?

Thats not a problem if you can see the driver but if you cant see it like in bandpass or horn. thats procedure will gets dificulties

[Svante]

Run my tone generator with a sawtooth wave and record the sound with a microphone and look at it with my spectrum analyzer (which also shows the waveform).

[Pano]

The sawtooth wave is a most excellent method to check polarity. I use it all the time.

The pulse checkers you are talking about are common in pro sound. You should ask at a music or PA store. I've never seen one in kit form, but there might be one.

[dangus]

Elektor Magazine published plans for such a thing, "Phase Check for Audio System", probably in #11 1990. It's also in the book"Build Your Own High-End Audio Equipment".

There's a transmitter box that generates pulses (line and mic level, and audible (if you add a little speaker), and a detector box that works with a built-in microphone or line inputs. I built a set, and it worked. You could probably generate the pulses using an audio editor and burn a CD, which could save building the transmitter box.

It might be on one of the Elektor audio project CD-ROMs, or if you ask a librarian nicely you might be able to get the book through an inter-library loan, or a copy of the magazine article.

[Rembulan]

Thanks for any sugestion I have found The schematic that I looking for from rolls, PT102 thats exactly that I looking for

[xedlinux]

Originally Posted by Rembulan

Thanks for any sugestion I have found The schematic that I looking for from rolls, PT102 thats exactly that I looking for

Hi,

Do this thing kit work when you build it? thanks.

[paalj]

Hi,
If you also want to check the polarity of your mic, have a look here: Build a Microphone Polarity Tester
I am using the circuit in fig 2. I guess this circuit also can be used for checking the polarity on a driver.
best,
Paal