Sure it was not to excuse Sennheiser, they are big enough to put the money in developing something proper. I was trying to point out it may in the end be that we reached the limit of the technology. Personally Over the years I had a few planars that I ended up selling because they where not sensitive enough for my use cases. The example you point is a proof they can be sensitive enough tough, although in the end it came out as a unrecommended headphone with lukewarm subjective evaluation. So headphone manufacturing is a game of compromise, I have no irrational praise for Senns, I don't currently own any, but I've come to generally accept that if I buy an open back, You somehow win in spatial quality, but it will not be a bass monster. I may be wrong in thinking that, broad generalities more often than not can be proven wrong because that's just what it is, a generality. I have my Fostex TH-X00 for deep bass, that is also dynamic. It is still to this day difficult to find something that ticks all the boxes, Sennheiser over the years released a few models that are loved so they are doing something right, but you just have to know their open backs will no do very well with subs, you only buy em if you're ok with that and the fact that they released a few sets that became classics and universally praised means that some people are OK with that.