In-ear headphones often struggle to compete with on-ear or over-the-ear headphones in terms of sound quality, but the Starbrick Be4 earphones manage to get within the range of those higher-end devices thanks to the use of precious metal. The headphones make use of beryllium, an element on the periodic table, which allows them to reproduce sound faithfully and without distortion while still ensuring the durability to keep up with daily use.
Beryllium is the lightest alkaline metal on the planet. This means that it's strength is comparable to most other metals, and yet it's also significantly lighter. In fact, by weight, beryllium is stronger than steel. As far as music is concerned, that quality of beryllium allows for headphones to play at louder volumes without sacrificing sound fidelity.
Using a precious metal typically jacks up the price, but the Starbrick Be4 earphones are surprisingly affordable. They retail for just $180, significantly less expensive than other high-end earphones.