DSD/DTS Comparisons.

[neil wilkes]

I am not certain this is in the right subforum, so mods - please move it if necessary.
What has been bugging me for a while now are these Depeche Mode SACD/DTS-DVD discs, and to try & find out exactly why I prefer the sound of the DTS-DVD over the SACD, as it should not be that way. Incidentally, I know a lot of people who are saying exactly the same about the Genesis discs, but I don;t have any of those so cannot comment.
So, as a sort of test (that may be flawed, open to suggestions here) I took "Ultra" and recorded in the first track from the SACD and then from the DTS-DVD.
What I was expecting & what I found were 2 different things. Okay - I found, as expected, that the DSD/SACD stream has a LOT of noise, and little else but, above 22KHz. This is par for the course on SACD due to the noise shaping that is required to make it listenable.
Again, as usual, there was also a steep roll-off at about 20KHz, down to 22K, then there seems to be SRC leftovers from 22KHz to 32KHz, then all that is there is noise. I strongly suspect that the apparent musical content from 22-32KHz is also noise shaping artifacts.
The DTS-DVD spectrum shows none of this noise, just the steep drop-off at 20KHz to 23KHz, then a slow slope to silence from there.

WHat I did not expect to find was the massively improved dynamic range on the decoded DTS - it is well over 35dB more dynamic.
The DSD stream (in dB RMS) peaks at -11db to a low of -67dB with an average of around -17.5dB.
The DTS stream, well. Peak RMS = -13dB, Min RMS = -101.5, Average = -19dB.
I was well surprised to see clear evidence of the DSD stream being raised in volume by 1.5dB - more than enough to make it louder to the ear - over the DTS stream, which judging from the detailed spectrum plot was created from the same mix/master.
Why pump the DSD up? However, the real shocker - for me - was the massive difference in dynamic range between the two, when the plot shows the brickwalling/compression to be identical over the 2 streams? The DTS stream has 88dB of Dynamic range - not including headroom. The DSD has a mere 56dB of range.

The listening test shows the DSD to be definitely harsher sounding - the DTS stream just sounds a lot warmer & more open & natural sounding.

Screenshot attached for reference.
Test Gear - Denon 3910 Universal Player into RME ADI-8 DS at 96KHz resolution, balanced inputs at +4dBu from there into an RME HDSP9652 and into Nuendo 4.2.2. Nothing inline, no differences at all between streams apart from the source.

 

[Lucanu]

Great Neil
You technically explain my feelings!
I really feel like DTS has more punch and a warmer sound while SACD sounds harsh on my SACD/DTS-DVD Genesis boxset
and I'm not using the best hardware here, so my impressions could have come from a not-so-good setup
Very good job here!!!

 

[Kazaam]

Hey, Neil... Interesting stuff there! It does seem odd that the dynamic range would differ noticeably if we're thinking that they came from the same master. But I'm not really smart enough to add anything to the discussion. Nonetheless, I look forward to reading what others might have to say.

At the very least, maybe now I can lift my head up a little bit even though I only have the DTS versions of the Depeche Mode albums.

 

[OldAsMono]

Very interesting Neil. I'm also focusing on Luca's comments on the Genesis comparisons. I don't want to sidetrack this post onto the Genesis set specifically but it seems like a good example. I bought the first Rhino Genesis set (1976 - 1982) thinking I was ordering the SACD versions, my ignorance and lack of checking. Actually rediscovered Genesis with the set and loved the music but couldn't help thinking about what I might be missing not having the SACDs. I then had to buy "The Trick of the Tail" import SACD to test the difference. I was hoping that the over brightness in the DTS version would be warmer on the SACD. Same brightness that is obviously the sound they went for on these sets. The question is what is the better version? Always subjective but I thought the SACD offered a slightly wider sound range. I can't help but think that I have been taught to believe the SACD is better and actually doubt myself. I'm in debate over buying the more expensive import SACD set on the next Peter Gabriel years set or settling for the cheaper US Rhino set that will lose the SACD layer. Do others on the list share Luca's thoughts and enjoy the DTS over the SACD on the Genesis sets? Of course the imports offer both so I can't go wrong. Again Neil, thanks for the insight you offered. Have you tried this comparison on other recordings to see if it is isolated to this Depeche Mode recording or a universal occurrence?

 

[neil wilkes]

I've not yet tried other SACD/DTS-DVD comparisons.
Depeche Mode's "Playing The Angel" is going to be the next tester.
Then I am going to analyze other DSD transfers, as it is the limited dynamic range that shocks the **** out of me.
I suspect - but as yet cannot be certain - it is the Noise Shaping causing this phenomena.
That the master is identical on the DM releases is apparent from the spectrum plot, with the sole exception that the SACD is pumped by around 25% to make it appear better (following the maxim that "louder = better" adhered to by A&R) than the RedBook/DTS versions.

 

[PossumPete]

I, too, have been programmed to think that SACD was better. I'm going to check my Genesis discs since I wasn't impressed with the SACD side. Neil, thanks for all the hard work and digging for the truth!

 

[Ge Someone]

I suspect - but as yet cannot be certain - it is the Noise Shaping causing this phenomena.

Sounds not unlikely, would it be possible to determine the dynamic range of only the 20-22000 Hz part of the SACD?

 

[neil wilkes]

Sounds not unlikely, would it be possible to determine the dynamic range of only the 20-22000 Hz part of the SACD?

It might be possible with some serious LPF done to the stream.
I'll try it & post the results back.
If it is the noise shaping, then it means that even with SACD filtering switched in (On the Denons it is possible to put in an LPF at 50KHz).
we'd still nowhere near low enough though - we'd need at least a 48dB/Octave filter set to 23KHz, possibly steeper & lower - and that will definitely cause artefacts due to the aliasing of such a steep filter.

 

[Almen]

I'd just like to link to this discussion/interview about SACD vs PCM/CD/DVD-A: http://sound.westhost.com/cd-sacd-dvda.htm

 

[Desmo888]

Neil,

For us laymen... Does this mean, "Save your money on the SACD and just purchase the DTS version?".

 

[dobyblue]

Neil,

For us laymen... Does this mean, "Save your money on the SACD and just purchase the DTS version?".

If you have a system capable of converting DSD>Analog directly I would strongly recommend seeking out the SACD versions. I have listened to Violator and Songs of F&D picking out tracks and listening several times to both versions and the dts mix doesn't compare at all to the SACD mix. The dts mix just sounds like lossy compression when comparing to the DSD mix. It's more open, sounds more lively and the surround presentation sounds much more like a discrete performance.

I've also found the same to be true with every Genesis SACD I've got. Perhaps for some the DSD>PCM conversion is preventing them from experiencing the SACD as it was meant to be heard.