The power problem of earphone chooses one of sides of earphone namely, for example, because listen,use earphone, must have sensitivity the characteristic with tall, low impedance, of course voice is even nice, for example the KSC series of American KOSS, PP, SP, KTXPRO. This kind of earphone because sensitivity is very tall, save with electrode, because this bears power is very low also, if be in card of the computer, sound, go up with large CD machine when using, want very attention, should move volume a few smaller, otherwise volume crosses congress attaint earphone. Major is mixed with earphone have a fever earphone, professional monitor headphone does not suit to have a fever certainly with, and a few have a fever earphone often boasts he is monitor headphone however. Card of the computer, sound had better be chosen with wheat of earphone, ear bear power is a few greater, especially computer game and Internet bar, should notice power wants gist durable.