Matt alluded to this, but you may want to remove the old drivers and do a reboot, install new, do a reboot and then check it.

Sometimes it is important to reboot between removal and install.
Not all programs/drivers act the same in the removal process.

I assume the system will revert to the original factory drivers after the first reboot (removal), so if you've already removed those original drivers, I'd have to rethink my idea.

I do not work here, but the benefits are still awesome
Make your sound your own!