"Then your ears are not golden, period." Harumph! But you misunderstand what the phase button does. If the speakers are wired out of phase anybody can hear that. Actually, it's a quite interesting thing to hear...nothing is really localizable. But the phase button inverts the absolute phase of the signal coming out of both speakers. In other words, with a bass drum hit do the speaker cones move outward at the initial strike or inward (as they are not supposed to). Supposedly this difference can be heard, but my speakers start rolling off below 100Hz, so I suspect that's why I have a very hard time discerning the absolute phase difference when I hit the button. -TD

From: Jim Choate <ravage@einstein.ssz.com> To: <cypherpunks@einstein.ssz.com> Subject: Re: Idea: The ultimate CD/DVD auditing tool (meow) Date: Wed, 9 Jul 2003 23:51:47 -0500 (CDT)

On Wed, 9 Jul 2003, Tyler Durden wrote:

...

Somebody wrote...

...

Yes this is for localization ---clicks are broadband, you need to identify which freq components are used. I still think humans can't discriminate the phase of a tone.

An interesting thing to try is to play with the "phase" button on many high-end gear. This supposedly matters for low frequencies, but despite my unarguably golden ears, I'm still not convinced I can hear the difference.

Then your ears are not golden, period.

A standard test of audio systems in PA's for example is related to 'speaker phase' (ie all the cones move out or in together at the same time). This is tested by putting a click on the line and then standing between pairs of speakers. It is quite easy to tell when the speakers are in phase. The same can be said for music (and no you don't need expensive high end equipment), garble the phase and things like echo become very(!!!) wierd. You just have to have the experience to know what to 'look' for.

A very(!) simple test to demonstrate/test your phase sensitivity (using even very low quality equipment) is to connect a speaker between the R and L channels (in essence it is driven by diff between the two channels). This tends to highlight the phase disparity between the two channels significantly enhancing the 'depth' of the music. Put a switch in there and then have a friend enable/disable the speaker without your knowledge. Then indicate what you think is the 'third speaker' setting. If you can't tell nearly 100% of the time then any money on high end equipment is a waste of your budget. This trick (was very popular in the 70's, especially for us Quadraphonic fans) was what eventually led to the sub-woofer we all know and love today (I do wish somebody would do something about those damn rattling cars though).

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