It is well understood that very early reflections fog the imaging process in our listening minds. Very early reflections are those that reach us within about 5 milliseconds of the direct signal. One of reflection will produce an image shift. Many of reflections will produce image blur. Suspending pipes near a speaker will create reflections. The diameter of the pipe determines the cross over frequency below which the image is not distorted. For a 2" pipe, the image distortion effect kicks in at a wavelength that equals the circumference of the pipe, about 6" which is about 2k Hz, the sound of "tsss".
We have discovered the subtle benefits of adding into the sound stage a set of low level reflections. These reflections are not inside the image formation time window of 0 to 5 ms but occur just outside of it in the 10 to 20 ms region. This reflection is still within the sound fusion time window, it is not heard as a seperate event but fuses with the perception of the whole sound without impacting, blurring or distorting the imaging capability of the speaker.