Issue regarding setting volume to 100% is detailed here.
Windows Vista/7/8/10: Set each application volume at 80-90% in order to avoid dynamic volume issue.If you have Windows Vista/7/8/10 then you have to enable 24 bit output in Windows Sound settings or Realtek HD Audio Manager as well. For example, in Winamp the setting is located in Preferences->Playback->Allow 24bit. This setting is application specific so you will have to search for it in application preferences/options.
Enable the audio output/playback to 32bit or 24bit instead of 16bit, as this will slightly improve audio quality.Windows XP: Don’t increase the Windows Audio Volume to 100%, instead set it to 80-90% max in order to decrease the effects of dynamic volume issue.Warning: Enabling this setting will change playback audio bit depth to 16bit and sample rate to 44100 Hz, and when disabling it windows will set will change playback audio bit depth to 24bit and sample rate to 48000 Hz. Optionally, you can also try "Dolby Access", "DTS Sound Unbound" or "Dolby Atmos for Headphones" options. Windows 10: If you wish to emulate 8 channels surround on a 2 channel headphones/speakers you need to right-click on Windows Volume tray icon-> Spatial Sounds-> select “Windows Sonic for Headphones”.The sound effects also change the sound not always in a good way, you might like it for your music but it might harm the audio positioning in games. The sound effects will slightly increase the DPC latency, which in turn could cause other problems like audio/video desynchronization or slow network/internet speed. You can read more on the impact of sound effects to DPC latency here. Be careful which settings or effects you enable.If you are using speakers and want to reduce speaker output from being picked up by the microphone then enable Acoustic Echo Cancellation option that's under Microphone Effects.
Having the bit-depth set to 24 bit will slightly improve the recording audio quality. The 44.1 kHz (44100 Hz) sample rate is the one used by most media (games, movies, music), while video DVDs use 48 kHz.
For a 5.1 audio system select 5.1 Speaker.