Building my home theater PC was actually by an accident. Started of with building a gaming rig with ASUS Top ATI 4850 graphic card, quad core CPU Q9550 and my old CRT 17 inch monitor.. The CRT monitor was straining my eyes and that forced me to upgrade to a full HD LCD monitor. Spend a bit more and manage to get DELL's 23inch Full HD monitor at a pretty good price RM630 at that time.. It had a HDMI port so i was able make full use of my graphic card. ATI 4850 requires a special converter for DVI to HDMI supplied together to be able to pass Audio plus video through the yellow DVI port output. It's getting a bit technical, but this is a technical subject anyway.
Getting HDMI audio is not such a simple task as one might think, unless of course you have the much never ATI 5570 and above graphic card. My earlier sound set up was pretty much simple, i was getting the sound directly from my motherboard to my old speakers (my old speakers was pretty good considering it's size, it's a portable Creative PS2000 speaker for PS2 actually). My ASUS motherboard had coaxial output so i was able to use it with my old speakers for a digital/SPDIF sound. This of course is a DVD quality sound set up. The speaker was able to create virtual dolby digital sound out of a 4.1 speaker set up. Things was going fine till i got my hands on new ONKYO SKF 330 set of speakers which had 2 front, 2 surround and 1 center speaker. I had a 5.0 speaker set up but no amplifier & sub woofer which is required to use this set up. So had to do some searching whats the best cheap set up I can assemble to experience full HD audio. Got tangle up with Blue ray movies in the process. Things was just getting more and more costly sad to say...

Checking around put Blue ray player option is still quite expensive in malaysia, around rm1200++. Even PS3 is around RM1400. Best option is to get the player true deals such as purchase with purchase program. A friend of mine bought an LCD TV so i was able to buy the blue ray player at a bargain rm500 (Sony BDP3000). So now i've got my blue ray player  but with no option to set up my speakers. I still needed an AV Receiver to connect my speakers and i wanted to experience True HD audio & DTS master audio from blue ray movies. My sony BDP3000 Blue ray player does not do decoding for DTS MA but it is capable to bit stream the audio out to the receiver, so this needs a receiver which can do decode the bitstreamed sound for True HD & DTS MA audio.

Ok, Let me explain a bit on the audio part as some might not quite understand as there is more to it than meets the eye. DVD audio is normally dolby digital format (48khz/16bit/448kbps- lossy), while Blue ray HD audio is Dolby Digital, DTS, True HD (96khz,24bit,18Mbps - lossless) & DTS-HD MA (96khz,24bit,18Mbps - lossless). If you want 7.1 or 8 channel sound only HD audio (True HD\DTS-HD MA) can do it, the rest is 5.1 channel. For my PC i only could output PCM audio through the HDMI cable as my graphic card does not support bit streaming, bit streaming is basically only passing the full audio some where else like your receiver to decode the full lossless audio. PCM audio is the audio already decode by your PC for instance then passed to the receiver to amplify the sound and output to the speaker. Due to Protective Audio Path rule, PCM audio that come out of your PC must be downsampled to DVD audio to protect the audio from being copied by other people. High definition content protection is much less the same as PAP but if the system does not support HDCP you'll not get video output. If the audio can be bit stream out from your PC then you can enjoy the full audio instead of being downsampled. Newer ATI graphic card able to support bitstreaming so if you can get blue ray rom this will be a good thing. Another option is to purchase an audio card with bitstreaming support and HDMI output. I didn't care about the audio from my PC as i was stuck with my current GC, but to get the audio through the ATI graphic card HDMI port is a bit hard. first u need to have the latest AV codecs in your pc, next you need the latest ati driver, realtek hd audio driver at real tek website and ati HD audio driver. This should enable your HDMI audio, power dvd 9 is also needed i believe if you use a blue ray rom instead of a standalone player. By the way i'm using XP os, some say Vista or win 7 would be easier to get the hdmi audio working. I tried many steps so i'm not so sure which worked but the basic thing is to make sure your software is up to date. For example if your audio codec id not up to date you won't get even the PCM output through your HDMI cable as multichannel PCM output is something new if you output using ur HDMI cable.

Your receiver will only display PCM as the audio input as no decoding is done by your receiver. My AV receiver is Yamaha RXV565, it supports 7.1 channels(minimum rms of 90 watt per channel). It also supports 4 HDMI input and 1 HDMI output, this is good for my future support also as my pc uses 1 input, my blue ray player 1, hopefull astro beyond set will use another and i'll still have 1 free HDMI input. The receiver does upscale 1080p but for PC it is a bit screwed up, so what i did is set video passthrough for my pc hdmi. The problem that i encountered is that my graphic card tried to upscale and my receiver also did something causing my video setting to reset. Best is to make sure only one system upscale the video and graphic card is the best option as it maintains good quality as it's meant for video.

By setting your blue ray player to bitstream the HD audio your receiver will be able to display True HD/DTS-HD MA depending on what audio language selected, only one of the HD audio will normally be supported. Currently my set up is still 5.1 with my boston powered or active subwoofer. I could get 2 more speakers and make it 7.1 but i don't have enough room to set that up. Do bare in mind that not all blue ray discs support 7.1 channel, some old movies only support up till 5.1 so 7.1 channel may not always be used and also some movies is taken with standard definition so check for the video and audio quality in the disc details. Listening to music from your PC may not sound best with the configuration, i'm not so sure why. Personally I suspect due to mp3 music is basically taken in stereo format so making it 5.1 may not be a good thing all the time. Perhaps if I can get my receiver to decode the sound then it may be better, but that's up to try another day. Thinking of using my motherboard to pass SPDIF digital audio to my receiver to see the difference if my receiver processes the music. For now that's about it, already a lengthy sharing but i believe it would help most of HTPC enthusiast. I'll try to add on more details in the future.