Does converting from DTS-HD MA to AC3 lead to lower quality versus extracting the DTS core?

Question

DTS Core is 1.5 mbps, AC-3 is 640 kbps, but I heard that AC-3 is much more efficient than DTS and that DTS at 1.5 mbps equals AC-3 at 640. However, if the source is DTS-HD MA, extracting the DTS core would only copy part of the audio data, whereas converting the whole DTS-HD MA to AC-3 would require re-encode. So am I correct if I say that resulting AC-3 would be inferior quality-wise than the DTS core (loose more of the original data)?

Answer 1

Technically, any transcoding from one lossy format (DTS core is lossy) to another lossy format would result in lower sound quality and or increase in coding artifacts. However, unless you have a rather expensive sound system, it's questionable as to whether or not you would actually notice it.

Transcoding from the decoded DTS-HD MA stream, where the output is lossless, and then encoding that output to AC3, should be a better option, since you are not going from lossy codec to lossy codec.