Various aspects of the Rosewill Nebula GX50 can be controlled within the official driver, which is why installing it even though you don't have to is a good idea.
As soon as you open the driver, you'll see its most useful feature - the system-wide equalizer. Here, you can (and should) adjust the midrange frequencies to compensate for what the headset lacks in its factory tuning. I suggest you push the 1,200 Hz and 3,600 Hz range to around +4 dB. You should hear significant improvement in the sound quality after doing so. You can save four different equalizer settings and switch between them by selecting one of the four offered "Profiles". The settings get saved locally (to your PC), not to the headset. If you'd like to keep your settings in an importable file, you can do so by pressing "Save" at the top of the window - that will create an INI file with your settings. There are two other buttons here -"3D" activates some strange effect that makes everything sound shallow and echoy (leave it off) and "Reset" flattens out the equalizer.
The "Effect" menu contains software emulations of various rooms - theater, bathroom, living room, and corridor. They're there for entertainment purposes only as there's absolutely no way anyone will want to use them permanently. I had a bit of fun with the "Theater" setting mainly because that's exactly what I imagine music sounds like when one is high on mushrooms. Jokes aside, leave this at "None" at all times.
The "Mic" menu lets us adjust the microphone's gain (volume), as well as boost or mute it. As the microphone is fairly quiet, boosting it is practically mandatory, as is setting the gain to 100. Since there's a microphone mute switch on the in-line control unit, I see no point in muting it through the driver.
The "Virtual 7.1" menu is, like the name suggests, where you'll activate or deactivate the virtual 7.1 Surround Sound. Here, you can also play around with the positions of all eight speakers and have them spin clockwise or counterclockwise to emulate the effects of surround sound. Just remember to reset these to their default positions after you're done experimenting because they will stay exactly like you leave them, which could lead to some weird spatial positioning and overall performance.