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Posted by Mathias Andersson (Member # 169) on 11-09-1999, 07:57 AM:
What are the technical specifications for the diffrent digital sound formats? My research came up with the following information:DOLBY DIGITAL
samplingfreq: 48 kHz, resolution: 16 bit
bitrate: 320 kbps, dynamic range: 92 dB
DTS
samplingfreq: 44,1 kHz, resolution: 20 bit
bitrate: 1103 kbps, dynamic range: 96 dB
SDDS
samplingfreq: 44,1 kHz, resolution: 20 bit
bitrate: ??? kbps, dynamic range: 90 dB
CDS
samplingfreq: 44,1 kHz, resolution: 16 bit
bitrate: ??? kbps, dynamic range: 90 dB
Could anyone fill in the gaps and make possible corrections. I know there are more specifications, but let's start here 
And...of course...I want the theoretical specs of each format, not the hardware specs, if you know what I mean.
Posted by Joe Redifer (Member # 3) on 11-09-1999, 07:46 PM:
SDDS is 16-bit, not 20, and features ATRAC version 2 compression, the same as the second generation of MiniDiscs, which apporximately 5:1 compression (closer to 4.5 or so). Dolby Digital (theatrical) is 12:1 compression (AC-3)but the home version is much less than that. You're pretty much right on the money with DTS. I'm not sure what DTS calls their compression scheme, but I have heard "Coherent Acoustics" however I'm not sure if that is only for the home version, which has yet even less compression. Try downloading the CDS manual from this site to see if it gives you the specs that you need.
Posted by Mathias Andersson (Member # 169) on 11-10-1999, 06:25 AM:
The compression scheme DTS is using is called APT-X100, developed by Audio Processing Technology - hence APT. www.aptx.com
Posted by Stefan Scholz (Member # 147) on 11-10-1999, 10:46 AM:
Compression rate on ATPX-100 about 4.5 : 1, that's right. Sony states their 4.5 as 5, DTS as 4, depends on your rounding.
Data transfer rate on SDDS approx 8000 kbps, the highest of all systems, but has to feed 12 full rate channels, as Subbass is backed up and discrete fullfrequency (20 khz).
Posted by Mathias Andersson (Member # 169) on 11-10-1999, 04:52 PM:
Stefan,
Is the bitrate for SDDS always the same? I mean with both 5.1 and 7.1 channels? If so, the compression rate is varying and would make the sound "quality" better with 5.1 channels than 7.1.
I also thought the right side track (SDDS) was identical to the left, but I've heard that this is wrong. And that the backup track sound worse...
Posted by Joe Redifer (Member # 3) on 11-10-1999, 06:44 PM:
The compression rate for SDDS is constant, I know that. From what I know (and I could be wrong) ATRAC compression works in full bandwidth stereo pairs, so there are always four pairs of tracks on any given film, and some of them may not be used. Add to that the crappy back-up tracks. Also, it is not 5.1 or 7.1, but 6 or 8. The subwoofer channel is FULL bandwidth, they just don't use it that way.