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# To SACD or not to SACD, that is the question. - Page 3

I personally never believed this "SACD equals CD" nonsense, because on my system the difference between the two is like night and day.

It got me thinking why some people believe CD can even theoretically be equal to SACD (or, say, 96/24 recordings), and I realized that those people are victims of some gross misconceptions:

(1)  The Nyquist Theorem. For those who understand what the theorem actually proves, it is patently obvious that the sampling rate of 44.1KHz is not sufficient to accurately record and reproduce live sound. An excerpt from http://en.wikipedia.org/wiki/Nyquist-Shannon_sampling_theorem: "In essence, the theorem shows that a bandlimited analog signal that has been sampled can be perfectly reconstructed from an infinite sequence of samples if the sampling rate exceeds 2B samples per second, where B is the highest frequency in the original signal ... The theorem assumes an idealization of any real-world situation, as it only applies to signals that are sampled for infinite time; any time-limited x(t) cannot be perfectly bandlimited. Perfect reconstruction is mathematically possible for the idealized model but only an approximation for real-world signals and sampling techniques, albeit in practice often a very good one."

(2) The myth of 16 bits covering the whole human hearing dynamic range. 1 bit of encoded signal amplitude is roughly equivalent to 6 db. Since the bit of a sample code word and decibels are both logarithmic quantities, 16 bits are equivalent to 6 db * 16 = 96 db, wich is indeed the range of a typical 44/16 DAC. The dynamic range of hearing, however, is 130 db: http://hyperphysics.phy-astr.gsu.edu/HBASE/sound/earsens.html. So, even in the case of pure sine wave, 96 db is not sufficient to cover the whole dynamic range. 24 bits fare much better: 6 db * 24 = 144 db. But wait, it gets even more interesting...

(3) Forgetting about multiple frequencies. At any given time, human hearing system can distinguish among about 24 different main frequencies (overtones are perceived as parts of the main frequency). Add a one more in between, and it will fuse with the two adjoining frequencies, the tree being perceived as one. This is actually a good news for recording, as practical music recordings don't usually contain over 24 main frequencies at any given time, and typically much less.

Now, imagine visually adding those frequencies together to form the resulting signal that is to be digitized. Let's don't take overtones into account for now, as their amplitudes are usually (but not always!) significantly lower. Imagine that at certain point in time all of these 24 sine waves are at their maximum positive amplitude. The resulting signal would have to be at 24x the amplitude of maximum allowed amplitude of an individual wave, which is roughly 6 db * 4.5 = 27 db. Which brings as to the overal dynamic range that is sufficient for reproduction of any practical music of 130 db + 27 db = 157 db!

Now, all of the waves maxing out at precisely same moment is a rare occasion, and if the recording tract clips momentarily, it won't be noticeable to most people, so the 24 bits range of 144 db is almost always sufficient. Still, this phenomenon is one of the reasons professional digital sound processing equipment uses at least 32 bits resolution, 48 bits having been quite common for the last decade, and 64 bits becoming more common now.

(4) Not taking into account multiple channels. SACD is a 5.1 format, that is, it contains 6 channels. Doubling number of channels provides 6 db bost to the dynamic range, so 6 channels can provide roughly 9 db of boost. 144 db (coming from 24 bits) + 9 db (coming from 6 channels) = 153 db, which gets pretty close to the ideal range of 157 db. In practice, two of those channels typically contain ambient sound information, so the overall boost is not that large, yet even 6 db are very helpful. Needless to say, the imaging of a 5.1 system is dramatically better than that of 2-channel one. It adds to the "presence effect". Subjective suppression of unwanted room reflections by the louder  back channels also plays its role in creating the "teleportation" feeling, as music sounds much closer to what the artist and recording engineers intended, without room echoes and colorations.

Now, SACD is not an ideal format. Its dynamic range is roughly equivalent to 120 db at 96 KHz sampling rate. And it is not surround enough, 7.1 being much closer to what is needed to provide a full illusion of "being there". So the current champion in home music reproduction is actually Blu-ray. Both DTS-HD master audio and Dolby True HD are capable of lossless recording of 7.1 24/96. I consider Blu- ray a successor to SACD, and, interestingly enough, it was also developed by Sony.

SACD is amazing, yet live music recorded in Blu-ray lossless formats can be jaw-dropping. I think this is the future - live concerts and elaborately mixed recordings rendered in Blu-ray.

Quote:
Originally Posted by rapunzel

Nah - that's the paper that got de-bunked over at sa-cd.net. Basically, it turns out the authors ... unbelievably ... selected some SACDs of things like Pink Floyd and other 70s stuff ... and even some early 80s digital recordings as their test discs ... stuff that wasn't hi-rez to start with ... but which existed on SACD because it had multi-channel support (perhaps form old multi-track recordings) and they didn't even realise that the recordings weren't hi-rez to start with  ... and they used these for their tests.

Garbage in. Garbage out.

As Ken Kessler says in Hi-Fi News and Record Review (Sept 2009):

" The fact that all SACDs these days are dual-layer means it’s no big deal to compare SACD with normal CD.

And despite reports by the mainstream press naysayers about the public not hearing the difference,

any music lover who can’t needs a session with an ear-wax remover"

### Gear mentioned in this thread:

Well, I got a Blu-Ray rw player already installed in the computer.  Do I now have to just wait for recording media to catch up to technology?

Since you seem knowledgeable in this subject, I'd like to ask the following questions

1) As far as I know, there is practically no music reproduction that requires a >96 dB range, if you room is quiet, you'd still have ~ 30 dB background noise, making a reproduced signal of 126 dB unlistenable since it would we too loud. So why would someone need a >16 bit recording for listening to music (I purposely exclude mastering, mixing, producing music).

2) No DAC or ADC has ever shown more than a -130 dB noise floor, or a better than  -120 dB THD+N due to thermal moise, RFI, whatever.., music beyond 20-21 bit is impossible to reproduce.

3) In practice, how often does music go beyond a 96 dB range, ie. if your loudest sound is 130 dB, I would assume softest significant sound is above 34 dB.

While 32 or even 64 bit might be useful for internal calculations, shouldn't 16 bit be sufficient for 99.9% of musical material, and 24 bit sufficient for the remaining .1%? Not to mention that the subjective dynamic range increases with proper noise shaping?

Quote:
Originally Posted by Krav

(2) The myth of 16 bits covering the whole human hearing dynamic range. 1 bit of encoded signal amplitude is roughly equivalent to 6 db. Since the bit of a sample code word and decibels are both logarithmic quantities, 16 bits are equivalent to 6 db * 16 = 96 db, wich is indeed the range of a typical 44/16 DAC. The dynamic range of hearing, however, is 130 db: http://hyperphysics.phy-astr.gsu.edu/HBASE/sound/earsens.html. So, even in the case of pure sine wave, 96 db is not sufficient to cover the whole dynamic range. 24 bits fare much better: 6 db * 24 = 144 db. But wait, it gets even more interesting...

(3) Forgetting about multiple frequencies. At any given time, human hearing system can distinguish among about 24 different main frequencies (overtones are perceived as parts of the main frequency). Add a one more in between, and it will fuse with the two adjoining frequencies, the tree being perceived as one. This is actually a good news for recording, as practical music recordings don't usually contain over 24 main frequencies at any given time, and typically much less.

Now, imagine visually adding those frequencies together to form the resulting signal that is to be digitized. Let's don't take overtones into account for now, as their amplitudes are usually (but not always!) significantly lower. Imagine that at certain point in time all of these 24 sine waves are at their maximum positive amplitude. The resulting signal would have to be at 24x the amplitude of maximum allowed amplitude of an individual wave, which is roughly 6 db * 4.5 = 27 db. Which brings as to the overal dynamic range that is sufficient for reproduction of any practical music of 130 db + 27 db = 157 db!

Now, all of the waves maxing out at precisely same moment is a rare occasion, and if the recording tract clips momentarily, it won't be noticeable to most people, so the 24 bits range of 144 db is almost always sufficient. Still, this phenomenon is one of the reasons professional digital sound processing equipment uses at least 32 bits resolution, 48 bits having been quite common for the last decade, and 64 bits becoming more common now.

1.  go to http://www.sa-cd.net/

2.  see if you find 5-10 of your favorite recordings on SACD

3.  if so, get a Sony SCD-CE595 SACD/CD changer or BDP-S370 Blu-ray/SACD/CD/DVD player for roughly \$160.00

4.  enjoy

That's how I started, basically.  Over 400 SACDs later, I'm still supporting the format.

Edited by soundboy - 7/21/10 at 1:17am

If you want a cheap way to get the most out of sacds you can try the following method:

This allows you use the PS3 as a SACD transport to send a 176.4 signal to an external DAC (but in my experience it doesn't work with every DAC).

The sound improvement compared to redbook is immediately noticeable IMO. Whether this is actually due to better mastering or better bit rate, I don't know.

^ Sea Change on SACD is incredible BTW

1.  go to http://www.sa-cd.net/

Hi Soundboy.

I can see from the prices that I'm not a SACD kinda guy.

Boo, Hoo.

The SACD players, as a one-time investment, as suggested, are cheap enough but trying to keep yourself in SACD's is worse than trying to keep my son in gaming material.

Wow!

Looks like I'm going have to find less expensive alternatives to high quality recorded material.  I understand the benefits of SACD but the price per SACD is too big of a hit on my wallet to make a habit out of it.  FWIW, I can go to a local used CD store (Streetlight Records) and pick-up eight disks (\$71.00 USD) for the price of basically one SACD so I'll have to keep my eyes out to see what more I can learn in regards to pricing.

If any pricing suggestions, (Other than stop being so cheap), I'm all ears.

Edited by beeman458 - 7/21/10 at 3:59pm

Streetlight Records....in the Bay Area?

Regarding prices of SACDs, I wouldn't go by what's posted over at sa-cd.net.  There're bargains to be had everywhere.  For example, any of the excellent Sony/BMG "Living Stereo" SACDs can be had for under \$10.00/each.  As a member of yourmusic.com, I can get the SACDs of the Carpenters, Eric Clapton, and some Elton John for \$6.99/each.  As with any audiophile/niche format, not everything is released on the format.  However, the sound quality is well worth it.

What titles are you looking for?

Quote:
Originally Posted by beeman458

1.  go to http://www.sa-cd.net/

Hi Soundboy.

I can see from the prices that I'm not a SACD kinda guy.

Boo, Hoo.

The SACE players, as a one-time investment, as suggested, are cheap enough but trying to keep yourself in SACD's is worse than trying to keep my son in gaming material.

Wow!

Looks like I'm going have to find less expensive alternatives to high quality recorded material.  I understand the benefits of SACD but the price per SACD is too big of a hit on my wallet to make a habit out of it.  FWIW, I can go to a local used CD store (Streetlight Records) and pick-up eight disks (\$71.00 USD) for the price of basically one SACD so I'll have to keep my eyes out to see what more I can learn in regards to pricing.

If any pricing suggestions, (Other than stop being so cheap), I'm all ears.

Are you just talking about the Aja SACD? What else did you specifically find that was so overpriced. I just gave you four examples of fanstastic discs at regular prices.

On top of this, here are a few more you can get readily at regular cd prices

Pink Floyd - Dark Side of the Moon

Steely Dan - Gaucho

Dire Straits - Brothers in Arms

Whole bunch of Telarc SACD's

Just to name a few.

Oh and here is an ebay store with 360 SACD's for 15-20\$ shipped each.

http://shop.ebay.com/soundcitybeaches/m.html

Edited by jilgiljongiljing - 7/21/10 at 11:00am
SACD prices are very reasonable until you get to the OOP stuff. Which is why you should buy discs when they come out. I used to use Borders coupons to get these now \$70 discs for \$10-\$12.

Quote:
Originally Posted by soundboy

Streetlight Records....in the Bay Area?

Regarding prices of SACDs, I wouldn't go by what's posted over at sa-cd.net.  There're bargains to be had everywhere.  For example, any of the excellent Sony/BMG "Living Stereo" SACDs can be had for under \$10.00/each.  As a member of yourmusic.com, I can get the SACDs of the Carpenters, Eric Clapton, and some Elton John for \$6.99/each.  As with any audiophile/niche format, not everything is released on the format.  However, the sound quality is well worth it.

What titles are you looking for?

I'm a High-End Performance oriented user, and SACD is worthwhile IF you are willing to pay for it and settle for an extremely limited catalog. "Not everything is released on the format." is one of the largest understatements ever made on this site.

Since ALL Classical and Jazz and Soundtracks amount to less than 9% (and that's the segment with the highest percentage of SACD releases, although still a small fraction) of Total CD sales. Look at the current Billboard Top 100 Popular (Rock, Alternative, Country, R&B etc.) and you'll find next to no titles available in SACD. I'd be amazed if there are any, but I don't care to put the effort into checking.

The real issue with SACD is that from the very beginning it was an Answer to a Question that 99% of consumers didn't ask. "Why isn't there a Better High Quality Music Playback medium than CD's" The fact is that most people listen to music on systems where they can't hear how a CD sounds, much less a better format. There is the entire 5.1 thing, which I did, and ultimately abandoned because it sounded too Gimmicky on most recordings (And I did it right whereas most peoples Home Theaters don't). The only chance it ever had of potentially replacing CD's is if from the beginning Sony had made CBS Records (At that point Sony/CBS's Music market-share was possibly large enough to drive the rest of the market) stop making any regular CD's at all. If every Disc released was always a CD / SACD Disc, and MOST Importantly at the same price. Sony (possibly one of the most inept marketing companies ever) decided instead to try and charge more for the discs and even worse get retailers to have to Double Inventory CD's and SACD's.

Most of us here at Head-Fi are part of a very small segment of the marketplace that actually cares about performance. Unfortunately we don't drive the Mass Marketplace. The great thing about High Resolution Downloads is that there isn't a Huge Investment in Mass Production costs to produce and market the software. So it's a viable Niche market. SACD is not a sustainable model. Yes there are many players. That's because it cost next to nothing to add SACD or DVD-A playback to a DVD Player, and it costs a lot to market separate SACD specific players. The bottleneck is not the Players, it's the Software.

Most music sold is Top 40 new releases, not back catalog. Yes you can get Dark Side of the Moon on SACD for \$17 or so, and you can pick up a USED CD of it for \$3-6 locally, or no-line.

I'm not saying SACD's are not worthwhile for us performance oriented collectors, but collecting SACD's is significantly more expensive than collecting CD's. It's sort of like Collecting Audiophile LP's compared to just collecting LP's. Audiophile (Heavy Virgin Vinyl) start at about \$25 (New) and go up from there. Whereas you can pick up tons of nice used LP's for a few bucks.

There are reasons to buy and collect SACD's, but affordability and catalog are not among them.

This is mostly the result of mastering, and not the result of sampling rates.  If you downsample a SACD to CD frequency, the human ear cannot tell them apart.  So, comparing an off-the-shell SACD to a CD of the same title is not a reliable test.  Downsample the SACD for your test.

Quote:
Originally Posted by podeschi

I don't agree (with the post that says there isn't a difference between SACD and CD).  On cans or on speakers I can tell the difference between between SACD and CDs.  There is a more artificial, metallic sound to CDs, whereas my SACDs sound more like (but not all the way) like vinyl.

Follow the money.  Of course the investors in SACD will try to debunk anything that says SACD isn't superior.  It's just like the ads that say coal is clean and wonderful.  Or the old cigarette ads that said smoking improved your health.  Follow the money.

Quote:
Originally Posted by rapunzel

Nah - that's the paper that got de-bunked over at sa-cd.net. Basically, it turns out the authors ... unbelievably ... selected some SACDs of things like Pink Floyd and other 70s stuff ... and even some early 80s digital recordings as their test discs ... stuff that wasn't hi-rez to start with ... but which existed on SACD because it had multi-channel support (perhaps form old multi-track recordings) and they didn't even realise that the recordings weren't hi-rez to start with  ... and they used these for their tests.

Garbage in. Garbage out.

As Ken Kessler says in Hi-Fi News and Record Review (Sept 2009):

" The fact that all SACDs these days are dual-layer means it’s no big deal to compare SACD with normal CD.

And despite reports by the mainstream press naysayers about the public not hearing the difference,

any music lover who can’t needs a session with an ear-wax remover"

Quote:
Originally Posted by Yikes

The real issue with SACD is that from the very beginning it was an Answer to a Question that 99% of consumers didn't ask. "Why isn't there a Better High Quality Music Playback medium than CD's" The fact is that most people listen to music on systems where they can't hear how a CD sounds, much less a better format.

From the very beginning, Porsche, BMW, and Ferrari provided the answer to a question that 99% of consumers didn't ask. That's exactly why they are cool and successful. They do what they do well.

MP3 is the McDonalds of the music world ... but we don't all *HAVE* to eat McDonalds. For people who want something nicer, there's SACD.

Quote:

The only chance it ever had of potentially replacing CD's ...

This is very confused. SACD does not have to REPLACE CDs ... it *IS* the CD physical format ... Every SACD machine plays every CD disc /// Every hybrid SACD disc plays on every CD player. It is both forward and backward compatible. It doesn't have to replace anything. It just seamlessly and perfectly coexists with everything. It's a very elegant way of advancing/evolving a physical format.

Quote:

Sony (possibly one of the most inept marketing companies ever) decided instead to try and charge more for the discs and even worse get retailers to have to Double Inventory CD's and SACD

YES - double inventory was a definite phail. I think those lessons have now mostly been learned. At the same time, the whole music  distribution market has completely changed since 2000 ... In the olde days, everything was brick and mortar retail, and brick and mortar did not want to stock Double Inventory. But those days are gone. Brick and mortar is going and gone. I now buy most of my discs from 4 or 5 superstores ... places like Amazon (various), or MDT.co.uk in the UK, or HMV Japan or JPC in Germany .. and it's really easy to find what you want. And they stock thousands of SACD titles.

Quote:

The great thing about High Resolution Downloads is that there isn't a Huge Investment in Mass Production costs to produce and market the software. So it's a viable Niche market

Well, there are self-evidently two problems with this argument:

FIRST, on the SUPPLY SIDE:   the quantity of available hi-rez downloads is just a tiny fraction of available SACD titles. I suspect this has much to do with the absence of DRM in the download world (what music label wants to sell one copy of the studio master and then lose control of it to p2p??)

Quote:
Originally Posted by rapunzel

Nah - that's the paper that got de-bunked over at sa-cd.net. Basically, it turns out the authors ... unbelievably ... selected some SACDs of things like Pink Floyd and other 70s stuff ... and even some early 80s digital recordings as their test discs ... stuff that wasn't hi-rez to start with ... but which existed on SACD because it had multi-channel support (perhaps form old multi-track recordings) and they didn't even realise that the recordings weren't hi-rez to start with  ... and they used these for their tests.

Garbage in. Garbage out.

hardly the most disinterested forum perhaps ?

several recordings however were High res ! - check the listings and details for their playlist, many were certified pure DSD or 24/96 PCM, admittedly not all, but many, but nobody was able to hear the degradation from **these** discs going to 16/44.1

Edited by nick_charles - 7/21/10 at 1:53pm
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