The way I checked the polarity of mine was to half-wave rectify a sine wave
and using that as a signal source, play it and then, using a microphone,
check on a 'scope which way up was the flat bit. It took a certain amount of
messing about with the EQ on the microphone mixer to get a clear image, but
it worked fine in the end.

S.

"TonyL" wrote in message
...
Eiron wrote:

You're supposed to be able to tell by placing the speakers face to
face, swapping the connections to one, and playing a mono source.
So one driver pushes while the other pulls, and there is little
output. If one midrange is inverted, there will be lots of output.
I never tried it myself. It might not work for HF where the wavelength
is short.


Yes, that is exactly how I determined that the bass drivers were correctly
phased. But I agree that this might not work well with the midrange and hf
drivers.