CurtPalme.com Home Theater Forum

[CZ Eddie]

The whole AC-3 thing was a bit before my time. Can someone tell me if the AC-3 DD works the same as the DD that is output via optical from my HD-A2 or Time Warner cable box?

Specifically, I'm looking at the old DC1 or DC2 from Lexicon to replace my Outlaw 950.

Thanks

[ecrabb]

AC-3 is the technical term (spec) for what is more commonly known as Dolby Digital.

In short, AC-3 = DD.

SC

[CZ Eddie]

So it's all good! Not a crappy 1/4 HD 960x480 version of 1920x1080 in video terms? Thanks.

[AnalogRocks]

Yeah it was called AC-3 when it hit Laser disks. They printed it large and made it known. YOU HAVE AC-3.
Aparently someone must have mistook it to mean AirConditioning Level 3 because some one of the higher ups at Dolby Labs didn't like the term and gave it the cold shoulder. Shortly after DVD was introduced they changed the terminology. Which of course had people asking "Why?" and "Is Dolby Digital the same as AC-3?"

Remember this class. It will be on the final exam.

[AnalogRocks]

Yeah it was called AC-3 when it hit Laser disks. They printed it large and made it known. YOU HAVE AC-3.
Aparently someone must have mistook it to mean AirConditioning Level 3 because some one of the higher ups at Dolby Labs didn't like the term and gave it the cold shoulder. Shortly after DVD was introduced they changed the terminology. Which of course had people asking "Why?" and "Is Dolby Digital the same as AC-3?"

Remember this class. It will be on the final exam.

[kschmit2]

you can read the specs here:

ATSC A/52B Digital Audio Compression (AC-3) (E-AC-3) Standard, Rev. B

http://www.atsc.org/standards/a_52b.pdf

[erikjohn]

I always thought AC-3 added the center channel(thus the 3) to the mix as a full range independent channel and the surround channels were decoded from the stereo front channels using Pro Logic or something similiar. I guess you learn something new everyday, go AC-3!

[ecrabb]

Here's some interesting reading:
http://en.wikipedia.org/wiki/Dolby_Digital

Specifically, where the "AC-3" term comes from:
Adaptive Transform Coder 3 (relates to the bitstream format of Dolby Digital)

SC

[CZ Eddie]

Thanks guys!