Nice project, but please improve you safety discipline when cutting on the table saw. Do not do crosscuts guiding along the fence and without the miter gauge. A miniscule shift in the angle of your wrist can send that piece of wood flying into your face and you could easily lose some fingers. I know this. A good friend.. a professional cabinet maker with many years of experience, got in a hurry one day and doing that same very thing you did here, buzzed off three fingers. Please be more careful. Take care and God bless.
It lifts the speakers up from my desk to bring the tweeters in line with the height of my ears. It also helps to isolate any mechanical vibrations to transfer to the desk surface which could affect the sound quality.