Originally Posted by DPowers
When I was a projectionist it was analog and broken into tracks. It runs through a main processor and through sep amps that handled the front, surrounds and rears. The actual set up is different for different theaters...even within the same movie house. The Audio track ran along one side of the film and was picked up by audio rollers along the way. I haven't been a projectionist for over 15 years, but I wouldn't doubt it hasn't changed much unless they went fully digital. I don't know if the new digital set ups are lossless.
I have no idea about digital theater but for film, none of the digital audio formats are lossless.
There are three main audio formats on film these days. Dolby Digital, DTS and SDDS. Dolby Digital and SDDS store the audio tracks on the film itself, DTS stores a time code on the film that is sync'ed to a CD player with the soundtrack.
Despite their not being lossless, I am always impressed with a good audio presentation in a theatre - something I could not possibly get at home. I guess it's because of the number of speakers, amp power, floor shaking bass etc. I would imagine there are folks in this forum who would have home gear that do that - I don't.
Also from memory the films also have a backup analogue track recorded in Dolby SR or something like that. It is usually noticeable when a film drops out of digital to analogue as the highs drop off suddenly. This is not good