I recommend the Yamaha HPH-150 (HPH-150B) open-type headphones.
I am pleased with them and pleasantly surprised. I use them with the PSR-SX900. They are very light and comfortable to wear, nothing to compress. It is also worth paying attention to the thin and light cable. They can be worn for a long time. The ears are not covered. In addition, thanks to the open design of the headphones, there is contact with the environment, and the ears do not heat up or sweat. The keyboard EQ allows you to correct the sound, for example by adding bass. In my case, this is not necessary, even though I am used to the sound from monitors and subwoofer when I can play loud.
Open headphones are more expensive than closed headphones. However, I cannot imagine using closed headphones (isolating from the environment) due to the complete closing of the ears and their sweating.
All in all, the sound is great and rivals much more expensive brands in my opinion. These headphones, however, are a Yamaha product.
Have a look at the Thomann store page, there are also reviews from other users:
https://www.thomann.de/en/search_dir.html?sw=HPH-150&smcs=2bee9d_6637 You can also find the HPH-150B headphones on Amazon.
Regards,
Andy