Perhaps you should look at Jeff Atwood's blog on sound cards from May 4th, 2011.
The default, built-in sound chips on
most motherboards have evolved from
"totally crap" to "surprisingly
decent" in the last 5 years. But
besides that, in this era of
ubiquitous quad core CPUs nearing 4
GHz, it'd be difficult to make a
plausible case that you need a
discrete set of silicon to handle
sound processing, even for the very
fanciest of 3D sound algorithms and
If Jeff is considered to be an expert, the need for EAX support died when processing power became sufficent to no longer require external hardware.
From the Wikipedia artcile on EAX:
According to Creative's OpenAL 1.1
specification, EAX should be
considered deprecated as a developer
interface. New development should use
OpenAL's EFX interface, which covers
all the EAX functionality and is more
tightly coupled with the overall
From Creative's post explaining OpenAL and Windows Vista (and subsequently Windows 7):
With Microsoft's decision to remove
the audio hardware layer in Windows
Vista, legacy DirectSound 3D games
will no longer use hardware 3D
algorithms for audio spatialization.
Instead they will have to rely upon
the new Microsoft software mixer that
is built into Windows Vista. This new
software mixer will give the users
basic audio support for their old
Direct Sound games but since it has no
hardware layer, all EAX® effects will
be lost, and no individual per-voice
processing can be performed using
dedicated hardware processing.
Legacy EAX games will likely not perform correctly on Windows Vista and Windows 7. From this March 09, 2011 of the Auzentech X-Meridian 7.1 2G Sound Card:
We cannot fault any current sound card
for lacking the ability to enable EAX
in legacy games. EAX is no longer a
standard used in PC game audio. If it
works in a game, it is simply a bonus
to the sound card buyer.
When EAX came out it was necessary for games to enable EAX for the game to utilize the hardware. Since DirectSound is no longer supported game developers should be using OpenAL, which enables hardware acceleration automatically (if supported by the device) or is otherwise handled through the software.
The list of OpenAL supported games is not extensive (in my opinion) but not all games require a highly emersive sound experience.