So I know what AC3 means of course, but what does AC3D mean in some releases?
- It means Dubbed. It’s a short name for AC3.Dubbed - The audio track(s) have been dubbed to match with the video track. - The same applies to DTSD -> DTS.Dubbed - Is this different from mic-dubbed and line-dubbed? My impression was that those only come as mono or stereo, but many AC3D releases have surround sound. - Edit: So apparently dubbing is just the process of adding audio to a video track, sometimes replacing or complementing the original one. The quality dependends on where the audio comes from, but all of them are called “dubbed”. 
 
- If I had to guess, it stands for Definitive 
- AC3D is the Native file format naming of the AC3D program no doubt it’s for the word Dimension as in 3rd Dimension ie 3D - That was my first thought as well, but most of the releases I see are not 3D movies. - Who mentioned 3D Movies ? - AC3D is a 3D design package from Inivis that’s been on the go almost 30 years - AC3D is one of the longest established 3D design software programs available today. In development from 1994 and commercially available since 1996, AC3D has grown to become a highly regarded and popular program. Inivis Limited, developers of 3D design software, purchased the complete rights to AC3D in 2002. Inivis is committed to developing AC3D’s functionality and multi-platform availability, whilst maintaining its user-friendly and client-focused reputation. - AC3D is suitable for anyone wishing to visualise their ideas in three dimensions. AC3D is used for a wide variety of purposes including game model creation, product prototypes, virtual reality simulations and data visualisation. - thanks for all the downvotes 👍 - Please read the room, this is very obviously not what I’m looking for. 
 
 
 


