dbx stereo??

[brycecroan]

Hi there.

I recently traded in a PCTV pro card for a WinfastTV2000XP which states on the box that it supports full dbx stereo. What is dbx stereo and is it supported by the TV stations in Australia? (ie PAL)

I've downloaded the latest drivers and whilst the picture quality is good, the sound is definately not stereo!

Thanks in advance.

[KingJohn]

Digital Audio vs. Analog Audio
The analog audio that accompanies analog video is simply modulated up onto a 4.5 MHz
subcarrier prior to inclusion in the broadcast envelope. Should stereo audio be desired, the
presence of a pilot tone signals the receiver that the base-band audio information consists of the
sum of the right and left channels, and that a difference signal is available at a slightly higher
frequency in the broadcast envelope. A Secondary Audio Program (SAP) may also be present at
yet another frequency. This method, sanctioned by the Broadcast Technical Systems
Committee, is similar to that used in FM stereo radio transmissions with the exception that a
frequency-dependent companding method known as dbx-TV, licensed by THAT Corporation, is
used to reduce the effects of system noise. If surround sound matrix information such as Dolby
Surround Pro Logic is included in the original source material, it is preserved by this transmission
method, allowing a receiver to reproduce the center and surround channels if desired.
On the other hand, a digital audio signal is created by digitizing the sound to be transmitted, then
compressing the number of bits needed to represent the audio signal using a compression
method called AC-3 (also known as Dolby Digital), which provides for 5 separate channels of
audio plus a low-frequency subwoofer channel.

http://www.hauppauge.com/html/dtv.pdf

[brycecroan]

Thanks for the relpy. That makes enough sence for me to understand what dbx stereo is, but does anyone know if it is used in Australia and / or why I can't receive stereo with the WinFast card?

I know the old Pimmacle card has a seperate chip used to decode stereo TV that the WinFast card doesn't have.

Thanks again.

[KingJohn]

I would have thought terrestrial television like the UK only uses Dolby, so those types of sets would be common. And at a guess I would think that digital TV might use it But the decoder would then need to pass it to a normal television.

[energy80s]

Most of the world uses NICAM stereo for TV transmission. I think that dbx was only used in the States.

[brycecroan]

Does Nicam stereo require a chipset other than the standard 878a chip on the tv card to be decoded? cause the Winfast card doesn't have one.
And there's no reference to it on the box.

I rekon it's a bit of false advertising from Leadtek. I've tried using powervcr, windvr and iuvcr and still no stereo.

little buggers.