Okay, it's a bit odd to compare a pair of 'proper' headphones like the Senn HD650 to a pair of clip ons which can be found for less than $40 but there is a reason for my enquiry. I have owned a few pairs of the KSC75's over the years, unfortunately they don't last that long with the wires breaking sooner or later. I usually use them with a small portable AM/FM radio for train or bike riding duties to keep me entertained.
I recently bought a pair of HD650's which was a bit of an impulse buy. I've had the HD600's in the past and now that I think back I did think the KS75's acquitted themselves pretty well against the '600's. Anyway, I've got the '650's and bought a dedicated headphone amp yesterday being a Cary Nighthawk which is reviewed as being a pretty honest amp which can never be accused of exaggerating what comes in and out the other end. I had a good listen to the HD650's last night and liked what I heard. On a whim today and for a bit of a laugh I plugged the KSC75's into the HP amp just to see if they could handle a bit more grunt. Low and behold they sounded great, different to the HD650's and not unpleasant at all. The soundstage was wider, the sound was more lively with more bottom end and open treble and the midrange was a little more laid back.
I've read that the HD650's can sound dark, I guess the KSC75's by comparison sound lively. My main speakers are ATC's which are known for having a more lively sound which perhaps explains why I'm preferring the Koss.
After all this waffle, my question is, what headphones would offer me a more lively (not bright) sound, perhaps like the little Koss clip ons as an alternative to my HD650's?