540s are special... I listen to so much high end hp and gear at a meet a month ago and found that my HD540 holds its own even in todays hifi market. A real gem.
Off topic, but how are the Sony F1s you have? Ive read that it has great soundstage/imaging....
not like HD600 3 blob
I can input little bit on F1 FWIW
They sound like kwap.
BUT, there is no equal in comfort. I am waiting on some dekoni fenestrated dt pads. beyer pads fit. i put 007 pads to try out. So you can control the "angle" with angled pads. from its stock i think 30 degrees you can increase to like 40 degrees or down to 20ish if you reverse angle the pad. Hopefully you understand what i mean.
Soundstage can be blobish, but generally it is immersive and 3D as sound will travel all over your head from one ear to the other and vice versa
Now, some songs sound AMAZING on them, but most won't RELATIVE to most mid-fi cans of today and the hifi of 80s/90s
In saying that, its a perfect browsing can for youtube and such and low volume music listening.
You can wear these ALL DAY with the right pads. Not like how people say you can wear hd600/ k701/ dt880 all day, like really ALL DAY all day
Its more of an "art piece" and a "brief romance" type of can. And one can live without them.
But if you get them for browsing and "easy listening" for example movies on moderate volume, older movies with very little music etc. voices and mids are "accurate enough"
and there is mid bass, though attenuated relative to something like a hd600, and no sub-bass really to speak of.
In terms of value: if one can acquire a decent pair around 100-150, and new pads for 50 and knows what they are getting, ok.
*Refurbing an old pair is a PITA
(due to fabric of headband and pad where ear would make contact with (sometimes yellow on old pairs and needs to be removed or layer of thin acoustically transparent felt needs to cover,) Stock pads were thin so ear would touch, but most aftermarket will make your ear free... like a bird... perfect comfort. Just needs Focal Utopia driver mod