Frequency range: 5Hz - 30kHz Impedance: 32 Ohms THD (total harmonic distortion): 0.05% Sensitivity: 105 dB noise cancellation: 10dB I bought these headphones for 200$ (they retail for 250) and I love them! I listen to heavy bass music (mostly dubstep) and these headphones handle it no problem. I'm not sure if I would recommend these headphones to someone who doesn't like to have a good amount of bass in their music. I use them with a Fiio E7 amp (minijack to ipod doc to bypass ipod amp) though it is not absolutely necessary and an iPhone...