An audiophile is someone who appreciates listening to well-reproduced music. This means they often research the technology involved, from recording through production and playback system, including the listening environment. As such, they may be aware of the pros and cons of different types of media (tape recordings, vinyl records, CDs, streaming services, etc.) or of tubed electronics versus solid state, various types of speaker drivers and enclosures, speaker placements, and room treatments, all of which affect sound.

An audiophile need not spend a fortune on exotic equipment. Much of the exorbitant cost is due to use of expensive materials and manufacturing techniques, not to mention marketing costs which do nothing for the sound. But some people will pay extra for a status brand name or the esthetic appearance.

A quite capable system can be composed of judiciously selected vintage elements, or even home-built devices, if one is skilled. Attention to system synergy (well matched components) and optimal setup can do magic.

There are companies that market to a lunatic fringe who believes in pseudoscientific claims. They will insist that there are significant audible effects from replacing stock AC cords, cables, and fuses with wildly overpriced aftermarket products, setting components on various intricately machined isolating or coupling devices, applying damping and weights, etc. While in some cases, there may be a theoretical basis for these treatments, the claims are exaggerated and the cost/benefit ratio is not justified. Confirmation bias is a big factor. Where there is a measurable effect, the same benefits can be achieved using simple inexpensive alternatives.