Where this set differs from most of the line is in its top end. The 570's high frequencies are more pronounced than the usual Sennheiser sound, as typified by the glorious HD600 and now-obsolete HD580. Of course, this also depends upon the source components you listen to. Cassettes and underpowered portable CD players might actually benefit from the 570's high-frequency boost, whereas most receivers or separate headphone amplifiers don't need it. Because the HD570 wants a fairly substantial signal to sound its best, however, it should not be used with most portable players.
Dedicated amplifiers produce the best sound.
This is a comfortable headset with a different tonal balance from most Sennheisers. However, if this is the sound you're looking for, the HD-570 is rugged and extremely well constructed. You'll get a lifetime of use out of them. With a frequency response of 18 to 22,000 Hz and a 120-ohm impedance, the HD570 mates beautifully with both home and personal stereos. I can hear sounds I have never heard before.