[quote name='dincz' timestamp='1410083664' post='2545877']
OK with active basses but the low input impedance will noticeably drop off the highs with a passive. Most small mixers don't offer a high impedance (instrument) input.
[/quote]
That sounds plausible. I have had no trouble with StingRay5, Dean stylist (passsive), MTD kingston 5(passive), or B.C.Rich Beast (dimarzio very hot passive).
A USB interface works ok, but you have to have a computer running.
The core of my recommendation is don't skimp on the headset. The difference between the sennheiser 201/202 and the hd25-1 is quite large.