Chassis sounds

A wire's outer wrap of insulation or shielding changes the sound of music passing through it. And so too does a chassis, a circuit board's outer wrap. I mentioned in yesterday's post, chassis serve many functional duties and a few aesthetic ones as well. What we didn't discuss is how chassis change sound, and rarely for the better. My co-founder in PS Audio, Stan Warren, disliked them greatly. One of the first products he produced under the Superphon brand he created after departing PS was called a Space Case. Constructed of acrylic because Stan did not like what a grounded metal chassis did to the sound, this transparent enclosure wasn't much on looks but certainly restricted little of the music. One of the reasons chassis affect sound is electrical in nature. Circuit boards and wires carry electricity that generates radiated fields. Placing a conductor in close proximity to any other electrical conductor disrupts the field and changes the flow of energy; and musical performance suffers. Most chassis are constructed from material that conduct electricity. This is a desired property because one of the many tasks chassis are charged with is electrical shielding. Radiated noise levels from inside and outside the chassis are reduced by electrically grounding the enclosure, which then acts as a shield. The real trick with chassis design, when sound quality matters, is maintaining adequate distance from the circuit boards inside. In products we build, careful attention is paid to keeping circuit boards away from metal surfaces. It doesn't take a lot of distance to make substantial improvements, in some case fractions of an inch are all that's necessary. Lastly, weight and construction techniques matter. Any piece of stereo equipment in the same room as the speakers risks contributing to sonic degradation if it's too light or flimsy. Yes, there's some merit to audio-by-the-pound. Chassis with too little mass act as microphones that pickup what the loudspeakers broadcast. This is one reason isolation bases and weights help sound quality. Chassis matter, and can be a contributing factor to sound quality, both good and bad.