Congrats
K9ozzy!

Definitely an endgame headphone for what you are looking for.

I enjoyed mines the time we were together, until I meet: HiFiMan Ayra

, its sound-stage and sound attributes fit better for what I'm asking on a wide sound-stage
musical headphone, gaming wise I think HD800S might be better.
Medium and more realistic sound-stage works better for me, like the one is generated by headphones such as: DT990 Pro and DT880 Premium.
Sennheiser HD800S magnified/artificial sound-stage has this "
inverse side mirror effect" on me.
Objects in the game, are farther than they appear same with AKG K712 Pro in a smaller degree. However, what make me look for something else was a random harsh and painful treble spike at 4KHz and the inconsistency of the headphone cup: sound change too much depending how they are seated on your head.
Don't get me wrong,
HD800S are fantastic headphones: unique, they worth every penny.
All headphones had a "honey moon period", none is perfect. Once that phase is over... you start to see/hear its flaws, made the choice if are the right fit for your ears; which workarounds are feasible or if you can find a better option for you. That's for all headphones, my friends.
If
fit is problematic... try to stretch them with a sneaker cardboard box, try different pads, headband etc.
If is its
frequency response (how they sound), EQ is a resource but,
this is my personal opinion, you shouldn't be in the need of EQ a $1000+ usd headphone. I'm all-in with EQ when you take a $200 - $400 headphone and fix or tweak and improve some sound traits that make them closer to a $1200+, because you are making compromises. Top tier headphone you should get what your asking and paying for, out of the box, you shouldn't need to EQ it to enjoy them, nor different pads or cables. That's just me.
Back to the HD800S, these cans were engineered specially to bring you a more immersive sound, are a physical surround gadget, that's why they are so sensible to its positioning. Added drivers were tune in a special way to recreate a spatial sound. We can see this proprietary driver tune technology in a smaller drivers like the GSP600 and GSP500 which combine with a fantastic surround binaural base processor like the GSX1000 you get something one of the best headphone simulated surround experiences on the market. Unfortunately, only for PC. With HD800S you don't need any gizmo, HD800S is true magic by itself.
Yesterday I receive from Drop:
Sennheiser + Drop PC38x , I tried a little bit, run my intro audio-test: I'm pretty stoked. I know these are using the same spacial tuned drivers from GSP600/500 but man they sound so different,
better different; someone at Drop is doing alchemy.
Review coming.
Back again to the HD800S, so as I said... you do not need an Surround sound processor
AT ALL, is like adding extra salt and oil to a tasty bacon, don't!
Wide sound-stage focus headphones like: HD800S, Ayra, LCD-4, LCD-GX, etc, to get the most of it, these
need a DAC with at least one DAC chip per channel, aka
DUAL CHIPSET DAC's. These are expensive above $500 and need an AMP. On
K9ozzy case is all set.
K9ozzy my suggestions are:
Budget wise, incredible improved sound-stage and spacial representation:
Topping D30 Pro - $400 usd, this one uses 4 DAC chips, 2 for each channel. After AKM factory was destroyed for a fire, Topping came up with these DAC design using 4 Cirrus-Logic entry-level chips to achieve similar sound-stage of $800 DACs. Besides of its wide sound-stage, D30 Pro is accurate, analytical and detail.
Another great option and warmer (better bass) same great soundstage is:
Soncoz Flagship: SGD1.

It has amazing measurements for cross-talk, smooth frequency response; is a better built product than D30 Pro,
it has linear power supply for each channel, which is unheard of on these price range. Dual DAC chipset uses SABRE ES9038Q2M (mid-range) - this is
my top recommendation its warmer and softer DAC properties can be a better fit for an accurate, analytical and cold nature of the HD800S. Is around $400 usd.
Another one which is pretty good is the THX Monolith DAC/Amp, includes 789 Amplification, is based on Dual AKM entry level chipsets, and offers the DIRAC Sensaround, which is an amazing binaural surround processing. Unfortunately is out of production.
The
Topping D70S is the best of the bunch for dual chipset design but it has a very low availability, and might be out of production as well, why? because is using Top-tier AKM DAC chipsets, as I mentioned, they are out of stock and out of production because their factory burned down to the ground... completely. MSRP was $530 now is around $650 to $1200. $650 is quite pricey but I think it worth every penny, - heck! even $800. D70S is an analytical, detail and precise, not sure how harsh can get with the HD800S of similar traits, can be improved boosted or exacerbated.
And finally, for a warmer top tier more available yet expensive option, will be something like the
Denafrips Ares II which doesn't use DAC Chips... is made as the old time Hi-Fi devices base on: R-2R DAC technology. Which it has a different sound representation
And analogy is: DAC chipsets create sound are like we see digital movies... very accurate, vivid, sharp colors, like Avengers Endgame. While
R-2R creates a more artistic, grainy image like you see on film movies, like Braveheart or 2001 Space Odyssey.
And that's it, I hope all these is useful