SACD vs Standard CD

[Bryn]

I have a surround set-up in one room which I intend to upgrade the speakers for in the near future. It’s used for playing SACDs, DVDAs, Blu-rays and surround FLACs, the latter from USB memory sticks. A favourite is a surround SACD of Stockhausen’s Gruppen. With that being the only work on the disc, it’s decidedly short measure but worth it.

[Ian_of_glos]

Thank you all for your advice. I will definitely try some of the recordings that you have recommended.

[Mal]

... the DACs of (say) the last ten years (under R&D pressure from the rise of computer audio) or so have effected a revolution in the sound of ye olde cd...

I disagree, if they could send a man to the moon, within ten years, in the 1960s, then you'd think engineers could develop a near optimal CD player in the 1980s. To me, at least, they sound as if they did. My 1990s NAD 5420 CD player sounds great!

[Stunsworth]

I disagree, if they could send a man to the moon, within ten years, in the 1960s, then you'd think engineers could develop a near optimal CD player in the 1980s. To me, at least, they sound as if they did. My 1990s NAD 5420 CD player sounds great!

I think the difference between CD's launch and now is the development of more powerful processors and chips. Remember that when CD was launched Phillips could only make 14 bit chips, and that's what their players used. CD was right at the edge of what could be achieved with mainstream electronics.

Then oversampling became almost universal, and now almost ever DAC can process 24/192 and DSD files.

[Mal]

... I have the original Sony SCD-1 player, which allows an easy switch between SACD (2-channel) and CD layers on SACD/CD hybrid discs, so that judgement is based on listening, rather than on a priori judgement about the superiority of SACD vs CD.

How do you avoid the placebo effect? Have you tried double blind testing with a large number of SACDs? OK it's difficult, fortunately, there have been serious double blind tests performed. The paper describing these concluded:

"no matter how good a stereo SACD or DVDA disc sounds, it could also be encoded onto a CD and sound the same to human ears..."

https://www.itwriting.com/blog/articles/is-high-resolution-audio-like-sacd-audibly-better-than-than-cd

Of course, as you have a decent multichannel set-up then SACD makes sense. But as I don't feel a great desire for such a set up, I'll probably just stick to CDs.

[Mal]

I think the difference between CD's launch and now is the development of more powerful processors and chips. Remember that when CD was launched Phillips could only make 14 bit chips, and that's what their players used. CD was right at the edge of what could be achieved with mainstream electronics.

Most flying things today, even some hang gliders, have more powerful processors and chips than Apollo 11, but none of them are putting a man on the moon. Just as a lunar explorer will ask about a flying thing, "does it take me the moon", I ask about a CD player, "does it take me to heaven". All this talk of processors is beside the point.

[HighlandDougie]

How do you avoid the placebo effect?

Playing the disc with the SCD-1 set to SACD, then immediately playing the disc with the SCD-1 set to CD. That's not difficult. One's ears can tell the difference. If I wanted to be geeky about it, I probably could arrange for some double blind-testing but, hey, life's too short. So I'm happy to continue with my placebo-effect belief that the SACD layer sounds better than the CD layer on hybrid discs. Ignorance triumphing over science, no doubt, but I've reached the stage in my life when I really don't give a toss what the experts think.

[richardfinegold]

Playing the disc with the SCD-1 set to SACD, then immediately playing the disc with the SCD-1 set to CD. That's not difficult. One's ears can tell the difference. If I wanted to be geeky about it, I probably could arrange for some double blind-testing but, hey, life's too short. So I'm happy to continue with my placebo-effect belief that the SACD layer sounds better than the CD layer on hybrid discs. Ignorance triumphing over science, no doubt, but I've reached the stage in my life when I really don't give a toss what the experts think.

And, regarding DACs, for regular CD play, I’ve had 2 DACs simultaneously (actually 3, including the DAC contained in the Oppo 105 transport) inputting into my preamp. Comparisons are made by hitting a button on the remote for the preamp.
Mal, have you actually spent time with a newer DAC, or are you content enough with your current setup that you are reflexively criticizing newer gear?

[richardfinegold]

I have a surround set-up in one room which I intend to upgrade the speakers for in the near future. It’s used for playing SACDs, DVDAs, Blu-rays and surround FLACs, the latter from USB memory sticks. A favourite is a surround SACD of Stockhausen’s Gruppen. With that being the only work on the disc, it’s decidedly short measure but worth it.

I haven’t tried any Multichannel downloads. They ought to be easy enough to play using the usb input of the Oppo

[Ian_of_glos]

Playing the disc with the SCD-1 set to SACD, then immediately playing the disc with the SCD-1 set to CD. That's not difficult. One's ears can tell the difference. If I wanted to be geeky about it, I probably could arrange for some double blind-testing but, hey, life's too short. So I'm happy to continue with my placebo-effect belief that the SACD layer sounds better than the CD layer on hybrid discs. Ignorance triumphing over science, no doubt, but I've reached the stage in my life when I really don't give a toss what the experts think.

Thank you - I agree with this observation and I have tried exactly the same experiment. The difference is subtle but nevertheless I think it is real.
Standard CDs often sound harsh to me but SACDs do not.
Also SACDs appear to be more detailed than exactly the same recording played as a CD.
I have seen lots of articles explaining that the human ear cannot hear the high frequency sounds that only a hires recording can reproduce, but I don't think that is the point. There is more information available in the hires file or SACD recording and my human ears at least hear this as additional detail. For example, to me woodwind sounds more natural on the SACD, although with some of the louder instruments (brass and percussion) I cannot hear any difference. I am not sure whether there is any technical explanation for this but it is enough for me to try and find SACD recordings wherever possible.

[johnb]

I am not sure whether there is any technical explanation for this but it is enough for me to try and find SACD recordings wherever possible.

I've been reading an article by John Swenson (an audio engineer) posted on the Squeezebox forum some years ago. I'm not sure I understand all of it and I can't vouch for whether his argument is valid but...

His thesis seems to be that the filters that DACs use to eliminate 'aliases' above the Nyquist frequency have become "very complex digital filters where multiple filter types are cascaded together" and that "These do their job, they attenuate the aliases but they seem to have some side affects."

In order to improve the situation he advocates external upsampling using simple filters (i.e. upsampling before the DAC) because "Many DACs use simpler filters (or NONE!) for the higher sample rates so using external upsampling can frequently give you better sound than filters in the chip."

So, on that basis, as HiRes music is already at a higher sampling rate and that would have a similar effect to the external upsampling that he advocates.

By the way, someone asked whether DAC's really needs to use anti-aliasing filters. This is his explanation:

When a DAC outputs a signal there are "aliases" above the half Nyquist frequency, these aliases can inter-modulate with the audio signals to produce spurious signals in the audio band which ARE audible. The reconstruction filter is there to get rid of these aliases. With redbook source this is difficult, the half Nyquist freequency is just barely above the audio band. In early days this was done with anolog filters, but they really messed up the sound. Then chip makers came up with using digital filters to do this. These are called "interpolation" filters because they add samples in between the original samples.

The full post is: https://forums.slimdevices.com/showt...l=1#post751357

(My beef with SACD is that the normal RCA or optical output connections of SACD players are limited to 48kHz (?) sampling rate - so it is impossible to play the HiRes data on most two channel systems.)

[Bryn]

Thank you - I agree with this observation and I have tried exactly the same experiment. The difference is subtle but nevertheless I think it is real.
Standard CDs often sound harsh to me but SACDs do not.
Also SACDs appear to be more detailed than exactly the same recording played as a CD.
I have seen lots of articles explaining that the human ear cannot hear the high frequency sounds that only a hires recording can reproduce, but I don't think that is the point. There is more information available in the hires file or SACD recording and my human ears at least hear this as additional detail. For example, to me woodwind sounds more natural on the SACD, although with some of the louder instruments (brass and percussion) I cannot hear any difference. I am not sure whether there is any technical explanation for this but it is enough for me to try and find SACD recordings wherever possible.

Indeed. A decade or so ago I read an article in a professional audio magazine (in a hospital waiting area) which dealt with this very issue. The main thrust was that the frequencies above the limit of human hearing nevertheless have a knock-on effect on those within the human range. The changes in ‘colouration’ may be subtle but are all to perceptible.

[Mal]

Mal, have you actually spent time with a newer DAC, or are you content enough with your current setup ...

Mostly content, but now and again something jars.

I spent many months with Spotify Premium on a Logitech Squeezebox Touch, which was "in the same ball park" as my CD player. I thought, and still think, my CD player was better, but that might be placebo... especially since the the Touch was discontinued...

I now do my serious listening through the NAD 5420 CD player + Graham Slee Novo Headphone amp. + Senn HD 650s

I'm fairly content with the way things are, just sometimes something really grates.

For instance, I played Bernstein/VPO/DG 477 5745 yesterday and had to turn if off - digital glare/shrillness was too much. I bought this CD recently based on a positive Spotify Premium listen a few years back. I plugged my Senn HD 650s into my computer and listened to DG 477 5745 on Spotify Free and it sounded "OK" as regards harshness, but the mid-range sounded like weak mud compared to my CD player. I reckon it's mid-eighties DG recording at fault, but i might be wrong. Any wonder-DACs that can fix such shrillness?

[Mal]

... the human ear cannot hear the ... sounds that only a hires recording can reproduce... There is more information available in the hires file ... and my human ears ... hear this as additional detail...

That doesn't make sense to me at all.

If you look at a TV set where the resolution is gradually, and incrementally, increased there will come a point where you can't tell the current resolution from the previous resolution. Magnify the screen and you will see that the higher resolution is indeed higher, but there is NO WAY you would tell that higher resolution form the lower resolution without magnification, the pictures look just as "natural" in lower as in higher. It doesn't matter if the broadcasters sends out an image at higher or lower resolution, there is no way you will see the difference.

In the case of music, you say you hear the additional detail, but that can only mean you *are* hearing high res sounds. That goes against the published paper I quoted earlier, humans just can't do this. Unless you have the famed Golden Ears!

[Mal]

Indeed. A decade or so ago I read an article in a professional audio magazine (in a hospital waiting area) which dealt with this very issue. The main thrust was that the frequencies above the limit of human hearing nevertheless have a knock-on effect on those within the human range. The changes in ‘colouration’ may be subtle but are all to perceptible.

Not according to the paper I quoted. Was the paper you read backed by extensive double blind tests? These "subtle changes" could be placebo effects.