Are dolby digital and AC-3 the same?


I'm a bit confused by these 2 terms. I've heard about a difference in bit rates, but that's about all. I currently own a Harman Kardon AVR55 reciever, that does AC-3 decoding, and I would like to use it in my home theater setup. I would like to use the money saved to go out and get 2 additional amps for my system, since the receiver has pre-outs. Also, do most DVD movies come with DD and DTS, or just one of the 2?
julpay09f4
A bit more light to help confuse.Did you know the AC-3 from the LD transport can not be carried by a Illuminatins D-60? It requires a video cable.I also had the same Pioneer AC-3processor. I sold mine to get Lazer DTS capability,before DVD came out.Kthresh said nothing that contradicted anything I said. You may have percieved it that way ,I didn't.On my present processor setup,I have the DD/DTS, input on one coax with signal recognition. Then I have the AC3 from the LD as a seprate coax input. Now the point I missed, is the question I don't know the ans to. As in, will your piece do DD,from a dvd player? Well, If it doesn't MSB,or others can do a chip upgrade cheap,I would guess.
Yes, Dolby Digital and AC-3 are the same "technology". All the comments about how it is hooked up have nothing to do with the Dolby circuitry.
The followinig site is a another valuable resource for any questions concerning audio and video questions, and will provide links to the Dolby site as well as others: http://www.rane.com/digi-dic.html.

I believe find the answers you are looking for. Happy Holidays!
Dolby Digital comes in a few flavors: 2.0/5.0/5.1/EX6.1. AC-3 is the older term for the Dolby Digital format and you normally won't hear that term used today. Any DVD that indicates Dolby Digital will be supported by your receiver. DTS is a digital 5.1/ES6.1 format but not Dolby Digital. Most likely your receiver only supports Dolby Digital 5.1 or less. DTS DVDs normally have a Dolby Digital option that allows your receiver to play DTS DVDs.