I only own the AKG K240 sextett i use for non musical listening mostly ...
For music i use the AKG K340 hibryd the most complex headphone on the market, and for the price without rival...
Well optimized, it takes me months to undetrstand how and why, they are on all acoustics count factors if not, the best, among the best if we use an average score ratio for each acoustic factor...
Someone very well known buy a costlier Raal and to experience satisfying bass paired it with a subwoofer... 
I can align other examples...
the K340 was never reedited because of his complex unpractical design for the young generation using phone and for the cost implied in research to improve it ...
I even read the long patent explanation of Dr. Gorike one of AKG founder...
The true marvel of AKG was this hibryd...
By the way i prefer speakers/dedicated acoustical room controls to mere headphone, the K340 is the only headphone making possible a musical experience for me with natural timbre, high as honey with no fatigue, bass i may felt with toes spatial cues from the original recording with a speakers like sound out of the head experience...
What other headphone could do this for any price ?
The sextett is a mythical small brother of the K340. The comparison stop there. A single dynamic cell do not compare in realism with the Hybrid dual cell with a crossover at 4,000 hertz (near the golden spot of perception for human ears). i like the sextett it is why i use it, but not for music really ....
@mahgister AKG Headphones
l still use AKG 240 headphones in a system l set up at my girlfriends place. The 240 MK II is still in production.
The brand was then a division of Philips when l bought them. I had over the years noticed AKG in use in many recording studios, often worn by musicians and conductors. Last night l was viewing a documentary of Jerry Goldsmith recording the score for “The River Wild” film, some 30 years ago. He was wearing AKG semi-open studio 240’s with the “gold” (no relation) ear pieces.
l know they are probably not used today, but a good indication they were highly regarded in the recording business at that time. AKG are excellent at isolating outside noise, and comfortable to wear for long periods monitoring loud music. Great for conducting a large orchestra and hearing the stereo mix, but not so good if sitting at home, and the door bell rings.
