Surround Audio Issues with Realtek ALC880(D) on HP Digital Media Center 558z with Media Center Edition SP2 Rollup

Symptom:
5.1 Surround speaker test does not individually address all speakers
properly, or speakers respond almost inaudibly. Playing DVD's I have
no center channel (and hence no voices) when system set to 5.1
surround. DVD's will only have audible voices if I select 2 speaker
mode, which then gets cloned onto all 5 speakers. There are no known
settings to enable / disable cloning of audio.

Machine Configuration:
HP 558z... 3.2ghz dual core, asus based board with onboard Realtek
ALC880(D) 7.1 audio. My system has Windows Media Center Edition with
SP2 rollup and all available updates applied from MS update site.
Machine further has all updates as released by HP for this device.
Finally, I have applied version R1.30 of the RealTek drivers as
provided on their website. It's not entirely clear when the problem
was introduced, but I have attempted to uninstall software, reinstall,
rollback various driver updates, etc.. to no avail. At this juncture I
have left machine with the most recent of all patches.

Logitech Z5500 5.1 speaker system connected via analog front, rear,
center/sub mini connector to stereo RCA connectors plugged to the
corresponding RCA receptors on rear of HP 558z. Logitech set to 6
Channel Direct sound with no effects applied. All speakers pass test
and volumes normalized / equal for all channels. Further, have
conducted all of the below tests with SP/DIF optical connection to HP
558z, no improvement to issue. Retained 6 point direct analog
connection as preferred configuration.

Testing Executed So Far:
PREMISE - I have done ALL basic troubleshooting of hardware, wiring,
speakers, general settings, gone through hours of HP support calls
having stepped through all the basic proceudres for troubleshooting
audio issues (setting 5.1 mode in Windows, setting 5.1 mode in RealTek
Sound Manager, setting 5.1 mode in DVD video codec (Purevideo, WinDVD,
PowerDVD). No change to condition.


1. RealTek Sound Manager Test Results:
a) Ensure all sound effects and Equalizer disabled. Enter RealTek Sound
Manager and set speakers to 5.1.
b) Click Front Left Speaker results in a test tone coming from both
Front Left and Rear Left speakers simultaneously at a reasonable output
volume.
c) Clicking Front Right Speaker results in a test tone coming from both
Front Right and Rear Right speakers simultaneously at a reasonable
output volume.
d) Clicking on the Center Speaker results in a very low tone,
approximately 15% of volume level heard during tests b and c, coming
from ALL speakers simultaneously.
e) Clicking on the Rear Left Speaker results in a very very low tone,
approximately 5% of volume heard during tests b and c, coming from Rear
Left Speaker.
f) Clicking on the Rear Right Speaker results in a very very low tone,
approximately 5% of volume heard during tests b and c, coming from Rear
Right Speaker.
e) Clicking on the Subwoofer results in NO sound from any speaker.
f) Set speakers to 4.0 and execute (b) And (c) above with same result.
g) Set speakers to 2.0/2.1 and only get sound from Front when clicking
Front (left and right respectively)

2. Windows XP Master Volume Test Results:
a) Ensure all sound effects in RealTek Sound Manager are disable. Set
speakers to 5.1 (which is also verifyable in the Audio and Sounds
Advanced Tab of Windows, showing 5.1.
b) MP3 and Media Center Television appears to clone front channel onto
rear, so sounds heard on Front Left are also heard in Rear Left (Right
respectively), Center has sound, and subwoofer Windows XP is able to
individually address each speaker as attached to the analog inputs.
Clearly, there is no wiring or speaker issues and audio is "mapped" to
the correct speaker according to this test.

3. Playing DVD's
a) Setting speakers to 5.1 mode results in the same conditions
experienced in TEST 1 above. There is a highly diminished center
channel and therefore voices are inaudible.
b) Setting speakers to 2.0/2.1 mode results in the same condition found
in TEST 2 above, whereby all audio is cloned to rear and center
channels. This allows for listening to a DVD (since voices are now
heard through front & rear right & rear.

This issue has driven me MAD! I have been trying everything I can
think of. Uninstall, reinstall. Reinstall codecs. etc etc etc. All
to no avail. Some basics are troubling me - how come the AC3 streams
get crosswired as in TEST 1 above and other 2 channel sources output to
ALL speakers as in TEST 2 above. In the Creative world I thought this
was like CMSS to create a virtual surround field. On the HP platform,
there is no provision for enabled or disabling such a field and I
cannot find anything anywhere else that would seem to create this. My
codecs to my knowledge are base Microsoft + ive tried for DVD nVidia
Purevideo, WinDVD, and PowerDVD codecs / players. All produce the same
conditions.

Help is GREATLY appreciated. I really want ot avoid totally wiping
this machine since ive put so much work into getting it configured to
this point....

Thanks!

Hmm, this does not seem to be getting much feedback. Could anyone
suggest alternate groups which I might post this issue for further
assistance?

Thanks much...

closure to this issue...

having become completely frustrated without a resolution nor any
suggestions from here and afar i took desperate measures...

took a creative xfi and desoldered the game port to make it fit within
the tight confines of the hp z558. loaded drivers, disable the onboard
realtek and...

xfi produced same issue!!! only difference i was able to get center and
sub, bur rear played only out front speakers.. ok, similar mapping
issues...

fortunately there seemss to be alarger base of creative users and
topics along these line. so, the fix?

uninstalled logitech webcam, then reinstalled creative xfi drivers and
va la! proper sound on each speaker. apparently known issues with
logitech nixing surround systems!!!!!

cheers