Topic: Dolby Surround But No Dts Or Dolby Digital (Read 70 times)

QDaddy · « **on:** August 04, 2004, 11:14:00 AM »

About a year ago a bought an S video/optical TOSLINK cable from System-Mods. The component outputs work well, but the optical isn't being picked up by my Sony theatre in a box.

Here's the weird part...

When I go into the MS dash to change the audio settings, I get only Mono, Stereo, and Dolby Surround. There's no DTS or Dolby Digital option. When playing a game, my receiver sees the optical input, but determines that it is a PGM 48 instead of DTS or DD... hence no surround sound.

Can the audio decoder chip go bad where I can't do surround, but everything else is ok?

Any suggestions would be appreciated

QDaddy · « **Reply #1 on:** August 04, 2004, 06:56:00 PM »

I just bought a Sony HT-DDW660 at Best Buy. Other than the xbox problem, it's a great unit for the price.

Who's cable are you using?

If I find anything, I'll pm you.

QDaddy · « **Reply #2 on:** August 04, 2004, 07:32:00 PM »

Aight... I hooked up the stock av cable and popped over to msdash. I found that dolby surround was still available just like with the toslink av cable. Uhhh, shouldn't that choice be gone?

I just wiped my c & e and installed new. I would assume that any settings that were being used are no longer an issue.

dethbunny · « **Reply #3 on:** August 05, 2004, 01:21:00 AM »

"Dolby Surround" is a common name for ProLogic, which is a form of surround sound encoded into two channels. As such, it can be output through the normal analog stereo outs.

If your MS dashboard doesn't give you the option to enable DTS and/or Dolby Digital, that tells me that your Xbox is not properly recognizing the optical out. Do you have the official MS unit, or some third-partry device?

QDaddy · « **Reply #4 on:** August 05, 2004, 06:17:00 AM »

It is a 3rd party cable (see first post) that I bought from System Mods. Even after switching to the stock cable, the Dolby Surround option was still available and selectable. I have taken apart the "box" in the middle of the cable. There are numerous resistors and a few caps, but nothing to write home about. I did notice that the pin-out was very strange and that I was having a problem finding a good ground on pin 18 (the mode 2 that enable's DTS/DD) I am hoping that cable is crap and my box is not screwed.

Would the digital jacks (optical and coax) provide ANY signal if pin 18 is not grounded? Or... would they just pass on 2 channel data?

I have removed the mod chip... same results.

I removed the mobo and noticed something a bit strange... There was a small "forign object" jumping a resistor very close to the av connection. Since I am going to install a spdif (coax) port directly to the back of the box, I was unable to test at such a late hour. When my install is complete, I will update my results.

Is Dolby Surround an option that is always active even with a stock cable? I've never noticed before, but I've never really made a note of it in the past.

Dammit, I love this place... where else can you bounce problems offa so many geeks?

QDaddy · « **Reply #5 on:** August 05, 2004, 06:52:00 AM »

Hoe-Lee Crap

Thank you fahrenheit. I thought I had F'ed something up.

QDaddy · « **Reply #6 on:** August 06, 2004, 05:57:00 AM »

Last night I installed a coax jack and everything went great. I don't know if it was removing the foriegn object, jostling the mobo, or the installation of that jack, but DD/DTS is now available. Thanks for all the help.

TIXe, I would suggest you get a new A/V cable.

bigfreak · « **Reply #7 on:** August 06, 2004, 07:45:00 AM »

Something in that high def pack flips switches in MS Dash. It's possible your third party connector does flip the proper switches?

I'm just a newb though.

Author Topic: Dolby Surround But No Dts Or Dolby Digital (Read 70 times)