By popular demand, Art Noxon’s original notebook material shall be presented without any fancy formatting, zooming, or image adjustment. The text is presented below to supplement the original. This week’s discussion focuses on a well-known nemesis: early side wall reflections.
…are very significant in the listening experience. We have 2 ears, which allows us to be very perceptive of incoming lateral sound. In HiFi, sidewall reflections are known to change the stereo imaging effect. The rule of thumb is to weaken or eliminate these early lateral reflections.
The most commonly understood lateral reflection is the sidewall reflection. It occurs at ear level on the side wall about half way between speaker and listener location. Right speaker is reflected into right ear.
There are two other lateral reflections that are just as important as the side wall reflection. Upper corner and lower corner sidewall reflections arrive a few milliseconds after the wall reflection. An 80 dB direct is followed by 3 side wall reflections within 8 ms, well inside the sound fusion time window.