XBOX 360 audio/video question...

[BadJeff]

I Wasn't ablt to find a straight answer searching around the internet so I'm curious is anyone knows the scoop on the following....
Initially, I Had the XBOX 360 connected to the tv via component cables and audio going to my reciever via optical connection. TV recognized the signal as 1080P and for the most part looked awesome. Audio registered and played through the reciever in DTS 5.1 very nicely, spatial perception was super sweet..... So I figured I would pick up a HDMI cable in order to keep the picture signal digital. Well, looks like when you use the HDMI cable the cable housing physically prevents you from plugging in the original adaptor that has the optical output. As most of you know HDMI carries both audio and video. So to get sound to the reciever I had to use the optical out on my tv and have since noticed that the sound is still quite good but not as good as it was with the optical going directly from the xbox to the reciever. The reciever shows all channels as well as the subwoofers as active but the 5.1 light does not come on. (Though the THX one does?). So I guess the question is.... is there a difference in audio signal quality between the HDMI and optical? Or am I just loosing a hint of quality due to the fact the audio is now being routed through an additional component?
Any feedback is greatly appreciated!

[mildtowild]

My guess would be the quality loss is from your tv converting the signal or a bad hdmi cable.

[BadJeff]

Originally Posted by mildtowild

My guess would be the quality loss is from your tv converting the signal or a bad hdmi cable.

Probably right... I did cheap out on the HDMI cable, some dude tried to talk me into the $80 one but from my personal experience they're not worth the premium. Tv must be a factor too, generally I keep all my cable going directly to their components, splitters and such always degrade things.

[QuadESL63]

I bet your TV is converting the (non-HD) multichannel DD/DTS bitstream from the HDMI link from the 360 into 2ch PCM on the optical output. I think I have seen someone mentioned that over at AVSForum a while back. That's why your "5.1" indicator on the receiver did not turn on because the receiver is not getting the discrete multichannels audio stream anymore.

You do have 2 options:

(1) Buy a receiver that can decode audio stream from HDMI (must be HDMI 1.1 or later). Here's is a catch: Xbox360 cannot pass through the latest HD discrete multichannel bitstream like Dolby Digital Plus, DTS HD Master Audio, etc. via its HDMI output for its HD-DVD add-on. However, gaming should be fine. Since I don't have a HDMI 360 (mine is old) check with the folks at AVSForum, etc.

(2) Bite the bullet and get the M$ HDMI cable kit which included a dongle with optical SPDIF output like your component cable. The dongle can be plugged in together with the HDMI cable. However, I haven't seen one in store... but then I haven't really looked for it so I could be wrong. Or, get the Elite which includes this dongle

[BadJeff]

Originally Posted by QuadESL63

I bet your TV is converting the (non-HD) multichannel DD/DTS bitstream from the HDMI link from the 360 into 2ch PCM on the optical output. I think I have seen someone mentioned that over at AVSForum a while back. That's why your "5.1" indicator on the receiver did not turn on because the receiver is not getting the discrete multichannels audio stream anymore.

You do have 2 options:

(1) Buy a receiver that can decode audio stream from HDMI (must be HDMI 1.1 or later). Here's is a catch: Xbox360 cannot pass through the latest HD discrete multichannel bitstream like Dolby Digital Plus, DTS HD Master Audio, etc. via its HDMI output for its HD-DVD add-on. However, gaming should be fine. Since I don't have a HDMI 360 (mine is old) check with the folks at AVSForum, etc.

(2) Bite the bullet and get the M$ HDMI cable kit which included a dongle with optical SPDIF output like your component cable. The dongle can be plugged in together with the HDMI cable. However, I haven't seen one in store... but then I haven't really looked for it so I could be wrong. Or, get the Elite which includes this dongle

Good info. Thanks. And yes, I just discovered yesterday the solution to my problem is to give M$ $60 of my cash in exchange for their HDMI cable that also has the optical output. Hmmmm..... buy COD4 or fancy cable what to do....