One of the questions I'm often asked is something like "what crossover parts do you use or what upgrades do you offer"? Before I founded Selah Audio I worked as a component buyer in the electronics industry. Part of my responsibility included working with design engineers to find suitable parts for a variety of products.
Some of the equipment we manufactured worked at very high frequencies way beyond the audio band. Slight deviations in passive components (resistors, inductors, and capacitors) often became critical to circuit performance.
The same can be true for high end audio; however, it seems that the claims made for exotic parts often have no scientific basis and lack the documentation to show that there's an audible difference (let alone if it's even closer to the source material you're listening to). Of course there are many opinions on this subject and if you ask 99 audiophiles you might receive 100 answers. Stay tuned as I discuss my thoughts on this and other subjects in the coming year...