In article , Terry Pinnell
writes
Could someone remind me of the simple test involving placing 'left'
and 'right' speakers close together facing each other please? Am I
right in recalling that they are in correct 'phase' when the volume
sounds reduced/muffled? Or is it the reverse?

(I have some cable extensions to do on the speakers that came with my
new PC, and both wires are identical, so I want to be sure I get it
right.)

The pink noise tests here (with downloadable tones) should do the job:
http://www.eminent-tech.com/music/multimediatest.html
--
fred
Plusnet - I hope you like vanilla