Technical parameters of the helmet is very important,beats, but it may be misleading, the arguments do not seem like a pretty good headset,beats by dr dre, the parameters of the helmet can not be flat. Impedance: Headphone impedance is the impedance of the short, which is the size of the coil inductance and DC resistance of the coil and Z = (R2 + ω2L2) 1 / 2. Civil and professional headphone headphone impedance is typically less than 100Ω,monster beats, 200Ω impedance headphones a little more professional, it is a power amplifier in order to