Millimeters matter

Oops. Sorry about yesterday's surprise post. Aaron Berger, a contributing writer to PS Tracks, posted right after I did and the mail system grabbed his article instead of mine. It was a good article, but quite a surprise! Here's today's post. Ever wonder how moving a loudspeaker a mere matter of inches can make a big difference in imaging? Here's an experiment for you to play with so you can see. Try toeing in your left and right speakers 1 inch and you'll discover the center image and the soundstage will change dramatically. Now, put them back to where they were and move one of the speakers backwards by 2 inches, relative to the other. What happens? The imaging shifts. Why? Because millimeters matter at high frequencies and meters matter on bass notes. For example, a 20Hz bass frequency is 56 feet in length, but a 10kHz treble note is a mere 1.3 inch long (53mm). So if you move your speakers backwards or forwards by a matter of inches, the bass will be unaffected but the high frequencies will be seriously changed. This is just one of the reasons why I have always been a proponent of separate subwoofers. You need to make tiny changes to affect imaging, but extremely large changes to affect bass. The main speakers are all about imaging and the separate woofers are all about bass: both have to be moved independently. That is, if you want the best sound. And who doesn't?