This site was created by Theo Lee, better known as Precogvision, an independent audio reviewer and a data analyst by trade. Theo previously reviewed regularly for Headphones.com and now contributes occasional guest articles while publishing independently on his YouTube channel.
Audio is filled with confident claims built on limited information. This tracker is an attempt to make one part of the hobby—what IEMs actually sell for—more transparent. The project applies an evidence-driven approach to audio by collecting secondary-market listings, identifying patterns, and making the underlying data visible rather than relying on anecdotal pricing.
It does not claim perfect accuracy. Listings can be stale, incorrectly matched, bundled, or missing important context, so estimates are presented alongside sample counts, confidence indicators, and source data.
The ranking list was created to make my subjective preferences as a reviewer more transparent. I first began maintaining it in 2021, during my early years in the audio hobby, as a way to organize what I had heard and better understand the qualities I consistently valued in an IEM.
It is not intended to be an objective hierarchy or a universal buying guide. The scores reflect my own subjective hearing and preferences, and another listener may reasonably arrive at very different conclusions. The list is intended to provide context for my reviews by showing how individual products compare within my broader body of experience.
Placed alongside the Market Tracker, the ranking list represents a marriage of subjective and objective information. The rankings communicate how I personally evaluate an IEM, while the tracker provides market data such as resale value, sample depth, and confidence. Together, they offer a more complete picture of not just how a product performs to me, but also how it performs in the real-world secondary market.