600 ohm is much better details and cleaner, mids r not so recessed and very deep bass than 250 ohms
provided it is still very hard to drive....
after recabled and modding,
no more sibliances, very deep and slamming!!! bass and mids r more forward due to the dual entry cables used.....fuller bottom end and very easily to match with any amp
just a right mixture for my beyer....the pads opens the dynamic range of beyer and tamed the highs considerably
i can listen to my beyer straight for 4 hours staight without any fatigue and my ears doesn't get hot and sweat
a great improvement