Surround sound test

[jchansen]

Hi gang.

Does anyone know where I can find a short but colorful test file for surround sound, AC3 or DTS?

Thanks!

[guns1inger]

If you have Vegas and DVDA you could make one yourself.

You can also download a few from here

http://www.digital-digest.com/dvd/downloads/trailers.html as VOBs

or here

http://www.sr.se/multikanal/english/e_index.stm

as wav files that you can burn onto CD. These will play as DD5.1 or DTS (depending on how they are encoded) through an DVD player with a digital connection an appropriate amp. Some of these are large (200mb +), but even the shorter ones are pretty good.

Just found another one

http://www.dts-phile.com/downloads/download-main.html

Good list of sites for people/groups experimenting in digital surround audio in wav or CD format. Most of these have downloads available.

[jchansen]

Thanks! I've downloaded a bunch of DD files, but I'm wondering if anyone has any insight into this process:

http://www.modernrecording.com/articles/soundav/link46.html

on a Mac. I burn the files to a CD, but they simply sound like white noise; I'm using an Apex player hooked up to a DD-enabled amplifier with the coaxial digital. I'm having trouble understanding how a CD could be anything other than two-channel PCM.

[Kurt S]

Dolby Digital is not a standard for audio CD's. In fact DTS has exclusive legal rights to 5.1 surround for CD's. Knowing this, most players will not play Dolby Digital from a CD, only a DVD. If you want to test it from a CD you need to encode it with the DTS format.

"I'm having trouble understanding how a CD could be anything other than two-channel PCM"

if you've ever listened to a DTS CD you will here a short digital sound at the very beginning of being played. This is a code that is sent to the player telling it that it is a DTS encoded signal. The player then switches on the DTS decoder and decodes the signal to the proper outputs.

[guns1inger]

I have played both DD and DTS encoded waves from a CD through my aging Pioneer DVD Player and AV amp without problems. I guess the Apex doesn't want to play ball. I haven't tried the CD's in other players because everyone else I know has there hooked up to at best a pro-logic amp, or an old stereo system (bloody ludites).

The 'pink' noise you are hearing is the un-decoded signal.

[jchansen]

Aha, so quite possibly these discs would work on a different player? Is it really as simple as encoding the audio to "dolby digital wav" and burning it as a redbook CD?

Can anyone shed any light on how the ac3 files I can create with APack differ from "dolby Digital WAVs"? I'm guessing sample rate and header information.

I sure don't remember seeing any software that encodes to DTS.