The best way to evaluate headphones is by listening to them. Listen to some acoustic guitar or piano music—you’ll easily hear the difference between good and not so good. But two headphones that sound very different often will have similar specs.
Probably the easiest and most useful spec is the price. In general, quality and performance are strongly related to the price tag. Driver size is an important spec, especially if you want big bass. Typically, the larger the driver, the greater its ability to reproduce bass frequencies. Specs such as frequency range, sensitivity, etc., may be helpful to knowledgeable buyers deciding between high-end studio headphones, but not especially helpful for a less knowledgeable buyer choosing among lower-end headphones. A more helpful way of choosing among types, models, and brands is to read both online professional reviews as well as the customer reviews on our website.