SACD v DVD A

there should be a FAQ on this

basically which is better quality, i would have thought dvd as its on a higher capacity disk, but ive just read that sacd are also on dvd media.
confused????

 

makes sense

 

actually i think sacd is higher capacity than a single layer dvd-a (titter). 4.7gb vs 6.? gb iirc. neither is enough for full resolution 5.1 surround sound so both have lossless compression schemes which make it possible.
cheers


julian

 

best ignore me then

as usual!

 

The disc capacity is the same on either format - either single density 4.7 GB or dual density 8.5+ GB. The dual density is simply two layers at 4.7 GB (approx) each. The media (ie. disc) is the Digital Versatile Disc.

DSD (ie. SACD), due to its "waveform" concept, contains lots of data per second of music - far more than 96Khz PCM (ie. DVD-A) and I guess a similar quantity to 192Khz sampled PCM (DVD-A). To the extent that it needs some compression to provide 74mins of music. I suppose this is why there isnt any room for visuals! (oh dear I'll cope). The differences between stereo and multi-channel DSD? I havent a clue.

 

SACD is not on DVD media - I don't where that came from.

Of the different encoding systems used (DSD of SACD vs. PCM of DVD-A) DSD (SACD) seems on paper to be the most attractive. It's a much more "natural" representation of the sound, almost analogue. You can look at a DSD bitstream and more or less draw the analogue wave form that made it by hand. PCM (the same system as used for CD) is somewhat more involved.

DVD-A encodes at 96kHz/24bit which is a lot more than the 44.1kHz/16bit of CD but the principles are identical. Both the encoding and decoding of PCM require extra steps that aren't required for DSD. At it's simplest a DAC for DSD can be just an analogue low pass filter

In overall resolution terms DSD is slightly better. It uses a 2.88Mhz sample frequency for 1 bit (delta sigma) samples. I don't know if it's correct to do this but if you divide that by 24 (the 24 bits of DVD-A) you get 120kHz which is higher than 96kHz.

I won't hide the fact that I'm an SACD supporter in the format war for various reasons despite having never heard either. As to which sounds better, clearly I can't comment from personal experience but I've heard equally good reports of both. The lesson seems to be that there really isn't that much between them in the sound quality stakes and the much more important thing is getting the recordings right.

From a purists point of view SACD will always be better. Since most (all?) digital recordings are done with a 1bit DSD ADC anyway why not just stick that information on the disc instead of having to go through a decimation step to get to 96/24 PCM first (and then having to reverse that step in the consumer DACs)?

The unfortunate issue though is that DSD is harder to edit so many DSD recordings are converted to 96/24 PCM anyway for editing so any advantage that DSD had is lost. The same is true of many universal players which convert DSD from SACDs to PCM before doing the analogue conversion.

One more thing, I think it's indicative that the heavy hitters in the audiophile scene (Krell, Classe and others) are bringing out SACD only players. Personally, I think that SACD is close to getting winning the format war. If DVD-A can't get reliable hybrid discs working (so far they haven't) then the format is a dead duck.

Michael.

 

The "quantity" of data per second of music is actually greater on SACD, the disc media capacity is the same on both formats, but there is far more to this than which format has the most data stored on it. This is a broad subject well discussed before here.

You need to consider what your objectives are before trying to decide which format you would be best to invest in. If the ultimate quality is your absolute concern then naturally only your ears will be able to tell you which you prefer. Maybe neither format presents enough compelling reasons to tempt you.

 

So a 4.7/8.5+GB disc isnt a Digital Versatile Disc? If not what would you describe it as?

 

Did any one know the real specification of both SACD and DVD-A ?
I still looking for the web site which are showing the converting of A/D and D/A both format.
And the technical issue of both




ie : for Audio cd

total bytes of 60mins = (44100 HZ x 16 bit x 2 channel x 3600 secs) / 8

Han

 

Michael: Very informative post, thank you.

 

It's a SDDC (Standard Digital Data Carrier) :
http://www.highfidelityreview.com/news/news.asp?newsnumber=12404812

 

Ahh makes sense - I guess the DVD TLA is just the most common tag.