As you can see, the G.I Rasta's have a frequency range of 100-18,000Hz, an impedance of 50ohms and a maximum input power of 400mW. On paper this seems to make the headphones sound quite restrictive, especially when you consider that the headset we are comparing the G.I Rasta's today has a frequency response of 10-27,000Hz and a maximum power input of 1000mW.