Sound quality difference between 32bit and 64bit client

I have been doing some further testing. Instead now I used my surround speaker setup (5.1) instead of headphones.

The 64bit client does not seem to have proper positional audio and does not seem to utilize the subwoofer (at all or at least not very well). The clients both have the same options selected when you launch them, so I am not sure why I would be hearing this sound difference.

Are there seperate config files for each client or do they share them?

Is there a reason why perhaps my X-Fi Titanium soundcard would be the culprit in this, instead of the game?

To clarify; on 5.1 setup (in the driver suite and volume panel of the soundcard) instead of 2.1 setup, the 32bit client has much better and more pronounced sound effects like described in the first post as well. Also, the 32bit client has much better positional sounds as a result too.