I see this is not an uncommon problem in TW2. The I played the tutorial the dialogue was fine but when I started the prologue I can barely heard Geralt and Roche voices. Most of the time the background noise drowns out the voices(when talking with Triss at the start) but also it seems like the bassiness of Geralts voice is the same as the ambient music so it kind of just blends into the background noise and I can't make out what is being said.

I have Dialogue volume set to 10 and Music/Ambeint or whatever they are set to 7. I have also edited the user config file and set these two values to 0.700000 and added a DialogueVolume=2 in-case this helped solve the issue but the problem remains.

My system is an Alienware M17xR4 and I have ensured the speaker setup is set top stereo.

Are there any other tweaks I could make to make sure the voices stand out more?

Can anyone offer any advice here? Is there a config file setting I am missing which will help resolve this problem?

my guess is the problem is on your end, your audio drivers or setup.

It only happens in this game and it is a well known issue going by the amount of forum discussions on this subject.

A known issue, and they never fixed it.

I will forgive them, as the game is amazing.

As noted, this is an ongoing issue with this game.

Ensure that you are facing the person who is talking. If you face away from them, their voice will be muted.

I don't know if it helps with this game, but it did improve the low voices for me in Skyrim and a bit in this game too. Click on your sound icon near your desktop clock. Then go to Sounds, then click on Playback devices. Now right click the speaker you use, go to properties Enhancements and check 'Loudness Equalization'. It help a bit with low voices.

Thanks, I'll give that a try.