The N810 is slightly faster, The hp power is low, but it appears to have nothing to due with headphone impedance, just the overall effeciency of the headphones. I just tried several sets I own and my 60-ohm Koss KTX/Pros do as well as or better than the many 16 to 30 ohm earbuds I own. The funny thing is that the sound from the built-in speakers are amazingly loud and good for what they are (tiny).