Thanks solderdude for your take... much appreciated. When it comes to build quality, that would be most important, and the reason why I sense the <$2500 zone should get me something well-made, well-liked, sub-extended and possibly endgame (if that exists?). I could be wrong? I've auditioned several mid-tier Hifiman models and despite some of them sounding very good, the build quality always forces me to either sell or return them. However, the EQ-able sub bass in their planars is really inviting!
The thing is that every headphone is a compromise.
Lightweight and sturdy can go hand in hand. For instance take the HD25. lightweight, you can throw them on the floor and whatnot. Every part was/is available. This is an old headphone. Take the HD580 ... other than the contact spring, paint jobs and foam Sennheiser headphones have not improved much. In fact ... when we see pricing of those long lasting products those have not inflated as much as many other products.
Take a brand like OLLO that makes headphones for the professional world. Every part is replaceable, you can literally play soccer with it. Nice materials being used. Yet they are still compromises in certain ways.
Higher end headphones usually have more exotic materials in them and maybe a more luxurious feel. These are usually treated more careful (because of the price) but thinner and more lightweight often comes with fragility.
Foam usually deteriorates, wood can crack, metals can break, plastics can break/wear nothing lives forever. Parts eventually stop being made and stock runs out.
Silent revisions often happen over years of production. Either through lack of materials being available, cost cutting or 'improvements' (which can go in every direction).
The one person that advanced planar drivers is indeed Dan Clark.
@Igor_S (Verum) who managed to DIY some headphone drivers and start a brand in Ukraine. It is amazing he can still deliver them.
Take Lily Audio (
@tonyng) who made a very lightweight and comfortable headphone which is also possible while using any decent dynamic driver.
Take HEDD for instance ... they make unique headphone (drivers) yet the newest and most affordable one is a dynamic driver. Sure a different membrane but many headphone drivers have different membranes.
Fosi's attempt in making the i5 was heading in the right direction in many ways. So is FiiO b.t.w. but these products have their issues and compromises too.
Will there still be spare parts in 5 years time ?
AKG, Sennheiser, Koss, Beyerdynamic, Shure, audio-technica and Audeze often still provide parts for popular products even well past 10 years of first production. Not all brands will do that.
It helps with 'longevity' and could be called 'build quality'.
Luxury brands produce luxury items at high prices but are they so much better in build/sound than certain cheaper mass produced headphones ?
Exotic materials may or may not be a good idea and may or may not cost a lot of money to produce and/or use. But do they really contribute to sound, sturdiness or longevity ? They sure will hike up the price and maybe even the profit margin. Will they sell many ? Will they recoup their investment ? Isn't a big part of the flagships marketing ?
All of these headphones are still compromises. Price, manufacturing costs/tooling, materials being available, profit margins, research/engineering, even vision of designers/manufacturers help shape a specific design. All of them will fail or be replaced with 'something better' over time. How much time depends on many factors.
And let's be honest. Does is really cost that much more to produce a Susvara compared to a Sundara ? Is the price difference in line with build quality and sound quality ?
Headphones are compromises. Well .. that's actually true for nearly every product.
All of them sound different, have different comfort and their downsides.
The fact that all of them sound different and feel different and exist in all price ranges is testimony they are all compromises.
Who is 'the best' at this and why ?
The fact that all of them sound different is because they are a compromise.
It is a market... manufacturers making 'something' and buyers having a preference for a 'story' or an actual product. A compromise.
Buy something (a compromise) you like/prefer at a price you can afford. There is no ideal product but there are many compromises in almost any price range where an owner can be happy with.
One can get sonic serenity at almost any price point but you will have to compromise.
Sorry for the rant...