Looking for suggestions

Hello all, first post! I have been trying to scratch that "perfect sounding" headphone itch since the early 80's, when I was in high school and I got my first pair of Radio Shack Optimus 25, and realized headphones could actually have some bass, and they didn't all need to sound so danged tinny. So, I have been doing this for a long time, since before Audiophile was a word, my wife has even accepted that my search for the perfect sounding personal audio will likely be a life long search for me, even going so far as to contribute a few pairs to my collection. Trust me, it is a bug that some of us will never shake. I have had countless headphones over the years, including some of my current batch are the Denon AH-D2000 and AH-D7000 (have both been sent off to Mark Lawton, who currently has the 7000s putting a new cable on them, could not recommend Mark's work more), Shure SE846, Fiio FH7 (my current favorite IEM of all time, and I have had countless), to name just a few, and numerous others. My favorite sound signature ever is the D7000, and even though I have purchased some that cost more than double those headphones nothing has come close to giving me goosebumps from the smooth clear bass the way those headphones do. So, enough about all of that, just wanted to provide you will a little bit of background. I also have a set of the original AKG K701s, the white ones, and they currently have a short in one ear. To be honest I never really cared for those cans (dating myself a bit, I suppose, with the old Headroom reference), while they opened up the soundstage like I had never heard, the bass was incredibly lacking, there was no oomph. So, ever since I have somewhat stayed away from open back headphones, because the ones I have had or listened to, simply did not have a bass level that could keep me listening. Not that I am a basshead, or anything of the sort, but I love my bass tight and fast. I primarily listen to Metal - Hard Rock, but my library contains literally every genre there is, so I am not looking for boomy bass, just something tight and fast that doesn't overwhelm the mids and the highs. I believe now is the time to take another look at open back headphones, and try to expand my horizons again, I need to temper my expectations some and understand what I am getting and looking for this time, as opposed to having a certain expectation not met. I am looking to find an open back set of cans, that really expands the soundstage, while also having tremendous acoustics and bass that I can hear clearly. I have been looking very closely at the AKG K7XX (which from the reviews, it sounds like they have made tremendous strides in the bass department), the Senny HD6XX, and the Senny HD58X. From what I have read the 58X has a tighter faster bass than the other two, so I am likely to order two sets, either the HD58X and the HD6XX, or the HD58X and the K7XX. For those of you who have any or all of these, can you tell me if I should pair the HD58X with the K7XX or the HD6XX? Any other Drop suggestions you might have, like the Focal Elex or any others, I am all ears. I will always have my 7000s, will probably be buried with those, so I am not necessarily looking to match their sound, just looking to expand my headphone horizons. On a side note, since I mentioned them earlier, I sure do miss the old Headroom folks. Such a great store, who took the time to email, or talk on the phone, sometimes for extended periods. A store that took the time to get to know you, and what you liked, just like I will forever owe Mike from there, as he is the one who directed me to the Denons, because he knew what I was looking for, he hit that recommendation out of the park. I miss stores like that, and believe me I spent thousands with them because of the personal level of their help. Things have become so much less personal, everything being done from a computer or phone screen, with little actual person interaction occurring. Thank you, very much, to anyone who might have some suggestions or recommendations.
100% upvoted

Nov 22, 2019
Yes, as rastus said, the Elex is the one. After that, the law of diminishing returns sets in as you go up in price. In my collection, after the Elex, there's the Stax L700's (mk2) which brings more detail (very tasty) but at the cost of a much narrower sound stage. Enjoy the Elex!
Nov 20, 2019
At <$1K, the Elex, you would have to go used, to better the SQ at the current $600 tag... Edit; there are others @ <$1K, that can do so much, in so many genres, with aplomb, as the Elex, but few...
It was an email only limited time sale right before you starting seeing them at $1200/1300. I've been tracking the HE6 and now HE6se for a sub $1`000 NIB with warranty for a many years now. This was the first and only time I found it below $1k AND in stock. I use it with a Cayin iHA-6 and from time to time with my Cube (when not wanting to be tied down to the primary listening area). The Cube just barely drives it in balanced mode (12 volts) and I definitely prefer the Cayin.
Nov 26, 2019
One other experiment I will be trying, is to explore MEMS a bit more, it quite interests me. I'm getting this evaluation kit, having a DSP - that you can play with:)), that very importantly comes with a set of beta MEMS - IEM's, on the cheap @ $77.50. Finished MEMS/IEM's, M&M's;) with miniaturized driver circuit, is available at $733.53, a tad steep,, to just toe step into MEMS... a perfect case of, "Move the decimal, and I'm in!"