I get similar issues with 5.1, it seems the game sound engine has a maximum setting of 4-speaker "surround sound" or you can pick stereo or mono, which is pretty old news. These days most computers have at least 2.1 and often 5.1 or 7.1 on the motherboard as in my case (optical and coax options, etc.).
So when I "look down" inside the cockpit I lose the subwoofer/centre speaker and get faded surround for the directionals. If I look back up, which is about level ahead I get all my speakers and a good volume, same to the left or right with directional sound. I only have this problem therefore when "looking" down into the cockpit, or out the side and down towards the ground. Then it's annoying and it actually makes me avoid looking around too much
The problem for me was worse without the sound mod however (093 installed, I still haven't figured out the pros and cons of SFX 6.0 or what it even does, there's no detailed explanation provided but it's much smaller so I figure, WIP or something). Since the mod you have to look down a bit further for the centre speakers to cut...probably just to do with sound quality and a better fade out since with 4 speakers the entire cockpit sound would just be a shade muffled when you look down-which is perfect (for those with a 4 speaker surround setup, i.e. nobody anywhere in the world anymore since we stopped buying milk in glass bottles and replaced steam engines with the petroleum combustion motor).
I mean as far as the sound engine for il2 is concerned, mind if i just ask...was it made when we all used 8-track casettes?
So the big question is...can anything be done to install a *modern* surround fix, i.e. for speaker setups and soundcards 5.1/7.1 :?:
Oh and the other problem for me is the sound volume for external engine noise is too low. If I turn it loud enough to really enjoy it, when I switch inside the cockpit I'm going to blow something. Is there any way I can manually alter it so that it is about halfway closer again to the internal cockpit volume?
Cheers