This headphone really has the best quality for headphones i have heard yet. I have always had in-ear plugs till now and i could never get this distortion-less bass in those.
I listen a lot to Techno/electro music and basically anything with a proper deep bass beat. And these headphones really blow me away.
First thing i noticed.. the headphones are not set automatically for deep base.. this you have to do in your equalizer from your source. Once you have done that you can really hear the deep tones in your favourite songs.
Next thing up, They are REALLY comfortable. You can wear them for hours without feeling any slight discomfort. Only thing is they do get your ears warm, so they'll sweat after sometime. But in this weather (February @ Boston, MA) it's great!

I would recommend these headphones to anyone who likes to pump up the bass in their songs, Especially for the low price at mini9ssd.com.