Turns out Beats headphones have weights in them to make them feel more premium (even though they’re shit):
One of the great things about the solo headphones is how substantial they feel. A little bit of weight makes the product feel solid, durable, and valuable. One way to do this cheaply is to make some components out of metal in order to add weight. In these headphones, 30% of the weight comes from four tiny metal parts that are there for the sole purpose of adding weight.
You can achieve this in the opposite way too: use a premium material, like metal, but try to make it weight as little as possible.