DTS audio compression lossy? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 6 Old 07-21-2019, 10:55 AM - Thread Starter
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DTS audio compression lossy?

At the company where I work we always use Linear Pulse-Code Modulation to record audio, we mostly do it for archival purposes these days. I personally do not do much mastering, I usually just do the recording work. For the past year or so, however, I have been remastering audio from original analog recordings into 8.1 LPCM at 24 bits and 48kHz. Such files always have the same bit rate of 9216 kbps. This is „true“ lossless audio (personally, I would not have called such audio lossless, but according to regulations, it is).

Well, long story short, the other day I got to preview a documentary, which has some of our archival footage in it. It has a respectable 8.1 DTS-HD Master Audio track at 3741 kbps (48kHz/24-bit), and from what I've heard it should sound exactly the same as any 8.1 LPCM track at 9216 kbps. However, I did notice a significant difference in audio quality in scenes with archival footage. Eventually, I contacted the audio engineer who had been working on this thing and he said that he simply cut and pasted the original files that I provided to him into the time line. He said that it must have been a compression artefact. But as far as I know DTS Master Audio is not supposed to have any compression artefacts, so has anyone else ever noticed anything like this? And is DTS-HD MA truly lossless?
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post #2 of 6 Old 07-22-2019, 05:25 AM
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Only very few of the best ears in the industry have been able to hear differences between AC3 and 44k already.
I have never heard of anyone being able to hear a difference between the higher bandwidth and lossless formats.


Things are different at the production and recording stage, though. Especially with saturation plugins or softsynths, a higher sample rate can make a huge difference, since the aliasing artifacts are kept away. But when downsampled correctly with good filters, the difference is almost gone.


A hifi-forum is not an adequate place to discuss such a question. I'd recommend an audio production forum where mastering engineers or re-recording mixers can give you their opinions.
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Good sound is always the result of engineering. And engineering always starts with measuring. Consumer industry and mainstream will never tell customers about that: improvements in room acoustics are worth roughly ten (10!) times the amount spent on equipment like speakers and receivers. For example: only $500 in room treatment is worth more than spending $5000 (fivethousand) on equipment.

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post #3 of 6 Old 07-22-2019, 09:53 AM
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Quote:
Originally Posted by Sith Kable View Post
And is DTS-HD MA truly lossless?
Yes, like zipping a file to take up less storage space. It's a bit for bit copy of the encoding master.

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post #4 of 6 Old 07-23-2019, 10:01 AM - Thread Starter
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Originally Posted by sdurani View Post
Yes, like zipping a file to take up less storage space. It's a bit for bit copy of the encoding master.
Well, once I converted the original DTS-HD audio track back into PCM, I could not notice any difference at all. I suspect that our equipment cannot really handle 8.1 DTS audio properly. It was just some issue with the receiver, I guess, but since I do not deal with compression, I can just let it slide.
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post #5 of 6 Old 07-23-2019, 11:00 PM
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So what's the extra channel? We're used to 7.1 systems with 8 channels of audio, so what's the extra channel in an 8.1 system?
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post #6 of 6 Old 07-24-2019, 03:12 PM - Thread Starter
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So what's the extra channel? We're used to 7.1 systems with 8 channels of audio, so what's the extra channel in an 8.1 system?
A standard 5.1-channel system with two surround back speakers and one top middle speaker
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dts hd master audio , lossless audio , lossless compression , lpcm , mastering

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