My other impression was that I don't hear any more stereo space in these headphones than in DT770, which is ridiculous as 770 are closed and 990 are open. I should be able to hear a huge difference.

I used the LP-phone-amp-g103 to drive all of these headphones so there shouldn't be any issues with the amp.

I wouldn't recommend DT990 Pro for casual listening. Most of your favourite songs may be unbearable to listen to. Besides that, as long as you can still hear a high frequency range up to 16kHz as I do, this part of the spectrum will be always taking the space and in front position. I've had quite a few headphones over the years for computer usage (Netflix, Youtube and gaming and of course since this year Zoom calls). When my last pair broke because of poor building quality I just decided I needed a more decent pair. Also I wanted to use them for more quiet bass sessions. I never had a pair that could actually handle the sound of my bass well. So I figured, Studio headphones should do. The second test was with a variety of genres, from Jazz to Ambient, Pop, 80's etc. Here's where "the fun" started. I tried a bunch of reference music for audiophiles out of curiosity (I'm not one of them!).

The DT 990 PRO is an open dynamic headphone of exceptional quality suitable for the most demanding professional and audiophile applications. The reduced weight of the diaphragm and moving coil result in a similar pulse characteristic as electrostatic headphones, and in combination with a carefully tailored frequency response offer a natural and balanced sound. Soft ear pads and adjustable, sliding, earpieces together with a very flexible coiled cable ensure listening comfort during extended periods of use. Here's What Beyerdynamic Say About the DT990 PRO Headphones Features The DT 990 PRO is an open dynamic headphone of exceptional quality suitable for the most demanding professional and audiophile applications.The corresponding models of both product families PRO and Edition are hardly distinguishable in terms of sound, as long as they have the same impedance (e.g. DT 880 Edition / 250 Ohm and DT 880 PRO / 250 Ohm sound the same). The series has been designed to cater for listening in a wide variety of environments, thanks to different headphone construction. The PRO range contains classic world-renowned studio headphones that are great for producing, mixing, mastering and other studio tasks. But you really do need to use a high-quality amplifier or audio interface to get the most out of these headphones. beyerdynamic’s DT PRO headphone series has it’s roots in the early 1980s. Since then, millions of audio professionals from all parts of the world have become loyal users of beyerdynamic products. In general, our DT 770 PRO, DT 700 PRO X and DT 990 PRO, DT 900 PRO X studio headphones are suitable for streamers and can be used for gaming accordingly. To find the perfect headset for your own use, we recommend our online gaming guide. +What is the difference between PRO and PRO X?

The low end was ok in most cases. It didn't have impact, weight or transient as DT770 but it is there. This is what I thought before I moved to the other music genres. The reduced weight of the diaphragm and moving coil result in a similar pulse characteristic as electrostatic headphones, and in combination with a carefully tailored frequency response offer a natural and balanced sound.The PRO models (DT 770 PRO, DT 880 PRO, DT 990 PRO) are designed for professional applications, e.g. in the recording studio. The Edition models are suitable for use at home on the stereo system. For mixing and mastering in the studio, open headphones are often used because of the better spatial representation. Our portfolio includes the DT 880 PRO, the DT 990 PRO, the DT 900 PRO X and the DT 1990 PRO. The hd-650 sounded like the 990's if someone put an equalizer on them that turned down every frequency past 3khz down 3-6db.