1. Go into "Control Panel" and then click "Sound".
2. Click on the "Playback" tab and then click just once, to highlight/select, the item you are trying to adjust (assuming it is speakers).
3. Once the item is highlighted/selected click the "Properties" button at the bottom of the window.
4. Now click on the "Enhancements" tab and make whatever changes you wish in there.
5. Be sure you click "Apply" (if available) and "OK".
NOTE: You should also consider clicking the "Configure" button on the main sound screen, after step 2 above.
As an Apache Pro VR user, I was horrified at the low volume of such a high spec device. The Apache Pro has 3D sound consisting of a dynamic sub-woofer and stereo front and rear speakers. The hardware is decent quality but the realtek driver only offers basic function and the Nahimic driver allows settings for VR and 3D. If you follow other guides and uninstall realtek driver, you will only be able to use either sub, front or rear speakers, not all at the same time. If you follow other guides and uninstall the Nahimic software, you will lose all dynamic sound, all 3D sound and will also lose VR sound capability. The basic windows driver does not boost the volume past what can be achieved by tweaking the Realtek and Nahimic settings. This is due to the nature of 3D volume balancing and binaural placement, the volume seems much lower than normal stereo speakers.
The best solution for louder volume (rather than trashing the functionality of the surround and 3D sound by disabling the drivers or tweaking the EQ to max - which destroys the fidelity of the sound) is just to simply "boost overall volume" with a separate program such as "FXsound" or "DFXsound".
Something like "FX sound" offers a decent 150% boost for free (with various other decent options) and also has a paid option for extra features and even more volume boost. It just installs alongside everything else so you don't need to uninstall/replace drivers or mess about with core audio settings. Just make sure "smart loudness" is on/enabled to protect the speakers from peaks/spikes in games and movies, then select a preset that suits either music/games/movies and you're away in seconds with acceptable volume again. I'm using the free version and considering paying (it's on sale at $20 today).