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saweetnesstrev
09-30-05, 05:49 AM
Will sacd on the PS3 be used optically? (HOPEFULLY?) instead of analog cords

gmontem
09-30-05, 11:15 AM
No. I don't think SPDIF has enough bandwidth for DSD. You're more likely to see output through analog and HDMI as soon as the HDMI spec is revised once more to allow DSD.

superklye
09-30-05, 11:29 AM
No. I don't think SPDIF has enough bandwidth for DSD. You're more likely to see output through analog and HDMI as soon as the HDMI spec is revised once more to allow DSD.
But don't current SACD players use a "standar" optical connection to hook up to home theater system? Why would it be any different for the PS3?

And I thought HDMI was a video-only connection, much like S-Video?

Ninjaman09
09-30-05, 11:32 AM
But don't current SACD players use a "standar" optical connection to hook up to home theater system? Why would it be any different for the PS3?

And I thought HDMI was a video-only connection, much like S-Video?
HDMI is a 5gb/second digital video + multichannel audio connection.

Rakeesh
09-30-05, 02:14 PM
You are almost doing an apples and oranges comparison here. These mediums deliver PCM audio, which involves multiple samples with each sample containing a waveform definition. (Pulse Code Modulation)

SACD on the other hand uses a 1-bit encoding technique. That one bit describes whether the wave is moving up or down in the next sample, and it does so at a very high sample rate of 2.8Mhz. (compare to DVD audio which is lossy 24-bit at only 192Khz samples)

This is incompatible with PCM; you'd have to either resample it to PCM, or encode it to AC3 or DTS in order for your digital sound system to play it.

Now if you are looking in terms of raw bandwidth, there are two forms of SPDIF to consider. Theres optical SPDIF which has a limit of 4Mbit/sec, and theres coaxial SPDIF which has a limit of 10Mbit/sec (yes, ironic as it is, coaxial has more bandwidth than optical toslink.) If you were to leave that audio lossless, you could probably fit mono SACD audio through an optical SPDIF connection, and possibly 3 channel audio through a coaxial SPDIF connection. If you want surround through one of these though, you're much better off doing a realtime DTS conversion.

superklye
09-30-05, 02:24 PM
Wow, that's some awesome info, A-Wolf. Thanks. :) Is there a site that you got that from or did you just know it off the top of your head?

Rakeesh
09-30-05, 02:36 PM
Wow, that's some awesome info, A-Wolf. Thanks. :) Is there a site that you got that from or did you just know it off the top of your head?

I knew most of it, but one fact (the sample rate of DSD) I had to look up. I just googled for SACD sample rate.

superklye
09-30-05, 02:48 PM
I knew most of it, but one fact (the sample rate of DSD) I had to look up. I just googled for SACD sample rate.
heh, fair enough.

Now, with a set-top SACD player hooked up to a home theater via either optical or coaxial connection, you're saying that it's actually being downsampled from 2.8MHz to only 192KHz?

Is there any system that can actually play SACD at SACD quality levels? Well, there must be, so then any CONSUMER system that can? If not, it seems as though SACD is completely pointless until the technology is available and relatively cheap. DVD-A is at 24bit/192KHz and any DVD player can play a DVD-A disc...albeit maybe not at the highest quality settings.

Or am I just missing something completely?

Bubba
09-30-05, 02:53 PM
i don't think signals from SACD can currently move over most digital connections, and I think the same is true for DVD-Audio. Most posts in AV forums that I have read indicate that it needs to be done over analog connections. The exception may be firewire or devon-link in specialty equipment. http://www.avsforum.com/avs-vb/

Rakeesh
09-30-05, 03:38 PM
Now, with a set-top SACD player hooked up to a home theater via either optical or coaxial connection, you're saying that it's actually being downsampled from 2.8MHz to only 192KHz?

That'll depend. It could go as low as 44.1Khz. But yeah, 192Khz would probably be the practical limit for current sound setups. Keep in mind though that most people can't tell much difference with audio samples somewhere over 60Khz. I think going beyond that kinda changes the way the audio makes you feel and not necessarily the quality of it. E.g. like the difference between reading under a flourescent light and reading under sunlight. I am not sure exactly what the benefit is as I don't generally listen to audio at that high of a quality.

Supposedly DSD audio more resembles an analog wave rather than a digital wave due to the 1-bit sampling I described, which I guess makes it more "natural."

Is there any system that can actually play SACD at SACD quality levels?

That I don't know about, as I am only aware of the technology itself.

What I can say is that DSD audio is relative rather than direct. Kinda similar to MPEG2 and 4, except it is lossless. If you lose one frame in the mpeg video stream, then the video will be off (e.g. blocky, faded, etc) until the next i-frame where you have a complete picture again.

(I don't know if DSD has an equivalent to an i-frame, but I would guess that it probably does, otherwise a scratch in the disc somewhere would potentially ruin the whole audio track. That said I don't know much about the encoding beyond what I just told you.)

With that said though, I would figure that SPDIF wouldn't be acceptable for this even in mono as it is proned to drops or jitter even in PCM audio. What would be good is to have some kind of delivery method that not only has high bandwidth and good shielding, but also includes support for a data redundancy layer.

Well, there must be, so then any CONSUMER system that can? If not, it seems as though SACD is completely pointless until the technology is available and relatively cheap.

I would guess so, but I don't know honestly. From what I heard, DSD is patent encumbered and expensive as hell for audio publishers to use due to the royalties alone.

i don't think signals from SACD can currently move over most digital connections, and I think the same is true for DVD-Audio.

Not any digital audio connections anyways. I would imagine something like USB2 or firewire as you said working easily. But if you are talking current generation consumer electronics, analog is probably the way to go as the majority of (all?) consumer DAC's out there only process PCM audio.

DVD Audio would work fine though. AFAIK it uses DTS, which has been well established to work fine over SPDIF.

superklye
09-30-05, 03:45 PM
Hmm...okay. Thanks a lot for the info. I'm a closet audiophile and this stuff is like the equivalent of baseball stats to a baseball fanatic (which I am also becoming) for me. I'm gonna research DSD some more.

Thanks again. :)

saweetnesstrev
09-30-05, 09:27 PM
Thanks. No idea how they gonna do SACD on PS3..