I read somewhere around people are talking about SACD (Super Audio Compact Disc) and I read many misunderstanding about SACD. I will write short explanation about it.
First, SACD is not a CD (there is SACD Hybrid, we will discuss it later). It’s different with CD standard. CD Audio will use PCM standard at 16 bit 44.1 kHz (this is the only standard for CD Audio). There’s no CD Audio with 24 bit 192 kHz (it’s a marketing gimmick to trick you).
On the other side, SACD will use what we call as DSD (Direct Stream Digital). It uses 1 bit delta-sigma modulation at very high sampling rate (2.8224 MHz) or over 64 times compared to CD Audio which runs at 44.1 kHz.
So it’s totally different architecture with CD Audio. So never expect about 16 bit or 192 kHz for SACD. It’s not using PCM, so forget about it. Also never compare the 1 bit (DSD) vs 16 bit (PCM) or 44.1 kHz (PCM) vs 2.8224 MHz (DSD). It’s totally in different league!
Despite of its controversy, DSD claims to have wider bandwidth up to 100 kHz and high dynamic range up to 120dB.
If we want to “look inside”, the PCM actually could support up to 100 kHz resolution (as DSD) at 192 kHz sampling rate (Nyquist theorem). While the 120db Dynamic Range claimed in DSD also could be provided with 20-24 bit PCM bit depth.
Most audio editing tools right now only support PCM (though later may support DSD-wide at 8 bit or PCM-narrow). So any DSD source should be converted to PCM domain before later converted to DSD again for SACD mastering.
Some people also say that with noise shaping technique used in SACD (it pushes the noise out of audio band), the SACD dynamic range may decrease quickly at frequencies beyond 20 kHz and also the raising noise floor effect. Some low pass filters may be added at the player side to compensate this problem.
There are few types of SACD:
– SACD Hybrid: This SACD is compatible with standard CD Audio player because it uses 2 layers. The first layer contains the data in PCM/CD Audio format. While the second layer contains the DSD/SACD.
– SACD Only: This CD is only compatible with SACD Player. Some SACD will have single layer (4.7 GB of data), some SACD will have double layer (8.4 GB of data). SACD also can provide multichannel 5.1 track, just like your DVD. So you can enjoy surround sound format from SACD.
William Chong
August 6, 2008 15:07Dear Brother Jimmy,
Since DSD Vs PCM is totally difference formulation, why does these DSD exist for, Is it for better sound reproduction or other issue ?
For audiophile, which format will reproduce a more natural high quality sound ? SACD on SACD Player or CD on Quality CD Player ?
How about ” upsampling ” like Cambridge Audio CD 740 upsampling to 24/384 Player ?
After upsampling, is the data represent the actual sound or they just use a formulation all add more date on the audio track ?
ha…ha…. All these marketing peoples make us very confused.
Best Regards,
William.
Jimmy Auw
August 6, 2008 15:37Hi,
People like to invent new technology, and DSD is one of the example. Off course they are looking for better sound reproduction.
So far most people still prefer CD on CD quality CD Player.
Good upsampling could produce good sound, but not always bigger number is better.
Actually it depends on the technology used and the result may vary. Most internal DAC will do the upsampling but at the end, you only listen the music (analog). No digital output provided at this upsampling number since it happens inside those microchip. If you use the digital out, most likely your CD Player will act as transport only (will disable the digital-to-analog function or the resampling feature).
Thanks.