There are a lot of factors that determine the final sound quality of headphones. Although nothing beats trying them in person, these specs can offer some guidance.
Impedance and Sensitivity: Impedance and sensitivity can speak to the wattage needed to output certain volume levels. Low impedance and high sensitivity headphones require less power and are better suited for small output devices like smartphones or MP3 players. The Beats by Dre Solo HD has a high impedance which may require an amp for best use.
Frequency Response: The frequency response indicates the range of pitches the headphones can produce. Human hearing range is usually quoted at 20 Hz – 20kHz, with most music falling well within those bounds. With a closed operating principle and a solid low end frequency response, these headphones can handle a strong bass and would be great for listening to pop or rock music.