My setup was:
Sansa Rockbox Clip+ > Fiio E5 > Ultrasone Pro 900.
I was very happy with the bass and SQ, but I wanted more. I read reviews and I'm a huge basshead so I decided to go with the ZO2 instead of the E11.
I received my ZO2 today, lowered the bass EQ on my Clip+ and tested my bass-heavy song "Dub King" at about 90% volume.
I immediately noticed that there's more detail, texture, and feedback to the bass as the song was building up. Then the beat drops and all I hear is distortion! There's about a 20% decrease in impact and 50% decrease in bass quality compared to my E5.
I tried the ZO2 with my HFI-580 and it sounds great! A little bit unnatural as you can tell the bass is artificially boosted, but very unique bass. It's excellent for certain genres. If it sounded like this on my Pro 900's, I'd keep it for sure.
I had high hopes for the ZO2 being a mini-subwoofer. I loved the design, the feel, the size...everything! But the bass disappointed me with my Pro 900. How can it sound pretty good with certain headphones, but horrible on others?
I tried my Clip+ > E11 > ZO2 > Pro 900's...bad idea...so I don't think it's a power issue.
I quickly went to buy the Fiio E11 amp to compare. There's the same detail, texture, and feedback as the ZO2 but with no distortion! I'm happy with my E11, but I wanted to fall in love with the ZO2.
Has anyone had the same experience with the ZO2 and Pro 900 or similar cans?
Edited by MrNurse - 2/3/12 at 5:29pm