Hey
@hierobryan,
I have owned the DT1990 for over 3 years now...I bought it as my first step into higher end studio reference monitor headphones from owning all of the ohm variations of the DT770s...I still use the DT770s to put on the heads of clients or friends I am recording just as reference monitors but otherwise I never touch them.
Before I go any further, know that I am an audio engineer and I DO meticulously EQ all of my headphones...
I found the DT1990s quite a step up as would be expected and quite surprisingly euphonic sometimes seemingly out of nowhere and when I least expected it...but I decided to try some planars...
First was the Hifiman Ananda for around $750 i think at the time I bought it...it may be cheaper now...it had fun, incredible soundstage but it was unnatural and the bass was there but also unconvincingly unnatural...I returned them rather quickly, ultimately.
Then on to the Audezes...The LCD-X 2021 was my next purchase and has remained my favorite headphone not just for engineering but for leisure listening as well. For $1200 it is not TOO much of an investment over the DT1990 considering the difference in overall quality in every area IMO. As a mastering headphone it is unparalleled IMO, as it responds majestically and with incredible sensitivity to any DSP effect I might add to my mixes...including the all important EQing. It is an offshoot of the Audeze LCD line specifically designed for engineers who want open backed headphones that sound like Studio monitors.
Now I realize that the LCD-5 is out there somewhere...but for $4000 it just doesn't seem like a practical investment for me when I'm so happy with the LCD-X. But I understand that it's resolution is even more remarkable than the LCD-X and comparable to the Utopia.
I own a $3000 Focal Stellia and though it is not a planar (it is Beryllium) it does have better resolution than the LCD-X but not by much...and to be honest I appreciate what the LCD-X can do in other areas that make up for that small amount of resolution loss...such as sub-bass that replicates very closely my 550 watt SVS PB2000 subwoofer which rates down to 16hz. This makes me think I may not be missing too much from the LCD-5's resolution which also has a smaller diaphragm than the LCD-X as well.
I also own the LCD-XC 2021 the closebacked version of the LCD-X. It has even more bass magnitude but requires a headphone amp to truly understand what it is capable of... that planar is a little more expensive than the LCD-X at $1300 but if you need a closebacked headphone like I do for microphone use (to avoid feedback looping), then it's worth it. Also if you need your headphones silent to not disturb anyone that might be nearby then that might be the headphone for you.
I also own the Sendy Peacock Planar at $1500 which while being a beautiful headphone I have little else to say about it...other than if you are all about looks (It's plated in 24k gold for one) rather than sound then...well then.
So to sum up all of this, I have found planars to be just majestic all around headphones vs. dynamic. While I can't see myself blowing $4000 on some of the flagship models out there...the LCD-X and XC have been my favorites and I have hardly touched my DT1990s since. Yes the DT1990s are exceptional especially for its price...but it is also only that good as well if that makes sense.
So I REALLY want to make it clear that I do not at all knock the DT1990s, in fact I've had MANY good years with the DT Beyerdynamics Series. They are great dynamic headphones in general!
So that's just my 2 pennies. I would encourage you to investigate planars on your own and not just take my word for it, but you if actually ended up reading all my crap (lol) then you can add my word to your own research and make your own judgments.
Blessings and happy journeys in your quest for sound!
-J
PS - The forum best to investigate the LCD-X and XC and to find my posted EQs for them on this site is:
https://www.head-fi.org/threads/lcd-x-and-xc-update.956949/page-173#post-17793011