How to grab DVD-Audio? Options

[ElevSkyMovie]

On a good system you should be able to hear the difference between cd and 24/96 dvd-audio stereo tracks. No one is saying we can hear frequencies that high, but the filters used for dvd-audio at 24/96 are much more gentle than that of cds. that makes a big difference.

I agree that the use of heavy peak limiting compression on dvd-audio is disappointing. The reason we are buying these discs is so we *don't* have that.

[precisionist]

On a good system you should be able to hear the difference between cd and 24/96 dvd-audio stereo tracks.  No one is saying we can hear frequencies that high, but the filters used for dvd-audio at 24/96 are much more gentle than that of cds.  that makes a big difference.

Sorry but that claim is useless unless varified by an ABX test.

[krabapple]

On a good system you should be able to hear the difference between cd and 24/96 dvd-audio stereo tracks.  No one is saying we can hear frequencies that high, but the filters used for dvd-audio at 24/96 are much more gentle than that of cds.  that makes a big difference.

On a *good* system -- which I'd define as one where the CD filter implementation is good too -- I think it would be very hard to tell the difference in a blind comparison, if not impossible. This is assuming, of course, that the same sources and signal chain were used in recording up until digitization, and the same mastering stage EQ/processing etc was used , for the two versions. Which isn't guaranteed.,

[ElevSkyMovie]

So you would rather have the brickwall filters on cd players versus the gentle slope filters that can be used in dvd-audio players?

[skamp]

All of the sudden I remember the title of this thread: "How to grab DVD-Audio"

[KikeG]

If brickwall filters on cd players have no audible consequences, then it doesn't matter.

[ElevSkyMovie]

They do have consequences, they cause distortion, especially in the high end.

[KikeG]

Could you elaborate? What kind of distortion?

This post has been edited by KikeG: Oct 20 2005, 14:52

[ElevSkyMovie]

When the Nyquist frequency is only slightly above the range of human hearing, you have to have a brick wall filter at 22kHZ. You want to have a flat frequency responce up to 20kHZ, but you can't have any signal/energy at 22kHZ or you'll get alias distortion. This requires a very sharp multipole filter with a very steep transition between the passband and the stopband. This causes distortion in the signal, smearing transients and causes ripples in the passband. If you try to simplify the filter, then you have to start rolling off at 13 - 15 kHZ to avoid unacceptable aliasing. Even then, the signal will not be completely cut off by 22kHZ. Using a higher sampling rate allows you to raise the cutoff frequency as well as use a much more gentle filter slope.

This post has been edited by ElevSkyMovie: Oct 20 2005, 15:47

[krabapple]

When the Nyquist frequency is only slightly above the range of human hearing, you have to have a brick wall filter at 22kHZ.  You want to have a flat frequency responce up to 20kHZ, but you can't have any signal/energy at 22kHZ or you'll get alias distortion.  This requires a very sharp multipole filter with a very steep transition between the passband and the stopband.  This causes distortion in the signal, smearing transients and causes ripples in the passband.  If you try to simplify the filter, then you have to start rolling off at 13 - 15 kHZ to avoid unacceptable aliasing.  Even then, the signal will not be completely cut off by 22kHZ.  Using a higher sampling rate allows you to raise the cutoff frequency as well as use a much more gentle filter slope.

Oversampling in CD players took care of this problem more than a decade ago. Please read this thread:
http://www.hydrogenaudio.org/forums/index....opic=8909&st=25

This post has been edited by krabapple: Oct 20 2005, 18:37

[ElevSkyMovie]

About aliasing: this is a non-issue in practice, unless you can hear very well on the range between 21.5 KHz and 23 KHz, where there is some remaining aliasing due to the filters used commonly.

I don't agree that aliasing is only contained in the freqencies that the filter is in. I believe that aliasing distortion can be heard in audible frequencies. My question is, why try so hard to make 44.1kHZ audio work if we can use a higher sampling rate that will enable us to move the filters to a higher frequency and allow for better filter design?

[dreamliner77]

I don't agree that aliasing is only contained in the freqencies that the filter is in.  I believe that aliasing distortion can be heard in audible frequencies. 

Prove it.

[ElevSkyMovie]

I think this article does a pretty good job of explaining it.

Love the avatar, dreamliner77.

This post has been edited by ElevSkyMovie: Oct 20 2005, 21:56

[precisionist]

I don't agree that aliasing is only contained in the freqencies that the filter is in.  I believe that aliasing distortion can be heard in audible frequencies. 

Prove it.

Yeah prove it. We require a blind listening test of you before you are allowed to spread this opinion. Articles, theoretical discussions, graphs and such don't prove anything. This is TOS#8.

[KikeG]

I think this article does a pretty good job of explaining it.

Interesting article, but it really doesn't say anything that many of us didn't know. Also, it doesn't prove in any way that the effects of the filters are in fact audible:

- Pre-echoes (more like pre-ringing) caused by sharp, phase linear FIR filters is hardly audible. Why? Because that pre-ringing has a frequency that is the same as the filter cutoff frequency. That means that the ringing frequency is of 20 KHz or more. Which is hardly audible, and, so far, there are no proofs of its audibility. Not to say that only very certain types of audio signals will excite such pre-ringing, signals that are not common at all in real world music.

- Lack of rejection of images isn't a big issue, because that has some importance only at frequencies very near half sampling frequency. In practice, it may have some effect on signals over 21 KHz, so, again, it will be hardly audible, and so far hasn't been proved to be audible with real world music.

- Real world musical signals have little energy at 20 KHz and over. There's much more energy below 20 KHz, which, thanks to masking effects, reinforces the lack of audibility of the previous two effects.

- Clipping due to reconstruction filters can only be attributed to poor and inadequate mastering.

Also:

- Linear phase FIR filters cause no phase distortion, as its own name implies.

- Common filter ripple is very below known thresholds of audibility (0.1 dB).

This post has been edited by KikeG: Oct 20 2005, 23:24

[ElevSkyMovie]

Yeah prove it.

I thought we were having an adult discussion.

This is TOS#8.

I don't know what this means since I'm new here. Enlighten me.

KikeG, thanks for the adult response.

Guys, if cds don't sound harsh to you, then keep listening to them.
I think that in properly designed equipment, cds can sound good. But
with a higher sampling frequency, there is more margin for error.

I have never done blind listening tests on cd/dvd-audio/sacd,
but I have listened to analog masters in studio that sounded
much better than the pressed cd.

[ElevSkyMovie]

This is TOS#8.

I found the terms of service, so no need to point it out.

[markanini]

I have never done blind listening tests on cd/dvd-audio/sacd,
but I have listened to analog masters in studio that sounded
much better than the pressed cd.

Ever heard of "mastering"?

[take_the_veil]

According to This relatively old story cppm has already been cracked (rarewares get a mention too.)

This post has been edited by take_the_veil: Oct 21 2005, 01:34

[ElevSkyMovie]

Ever heard of "mastering"?

Nope.

This post has been edited by ElevSkyMovie: Oct 21 2005, 01:37

[rjamorim]

According to This relatively old story cppm has already been cracked (rarewares get a mention too.)

Nope. CPPM is still going strong and unbroken.

What people (MaximA) broke was one of the links in the DVD-A DRM chain (he patched WinDVD routines related to data output, and not related to CPPM). CPPM, as a cryptography method, has never been broken.

This post has been edited by rjamorim: Oct 21 2005, 01:43

[dreamliner77]

I think this article does a pretty good job of explaining it.

Love the avatar, dreamliner77.

I'll print the article out at work tomorrow and read it.

And thanks, I like it too

[skamp]

According to This relatively old story cppm has already been cracked (rarewares get a mention too.)

OK there's definitely a problem if you refer to an external article about a story that started... in this very thread!
Dudes, this lengthy thread (272 posts) is entitled "How to grab DVD-Audio?", can we please stop extending it with completely off-topic posts?

[precisionist]

Yeah prove it.

I thought we were having an adult discussion.

OK, so you think I'm an ignorant stubborn child keeping bothering you with my annoying and disturbing demands ? A little more respect to the forum and me wouldn't harm.

This is TOS#8.

I don't know what this means since I'm new here. Enlighten me.

In case this wasn't ment sarcastically: Have you read it ? I doubt that.

I have never done blind listening tests on cd/dvd-audio/sacd,
but I have listened to analog masters in studio that sounded
much better than the pressed cd.

How can you be sure they did ? Isn't it possible that you just thought they sounded better because you did know that they were analog masters ? You have to be critical towards yourself and search for a way to eliminate your own illusion.
If you get angry about that ignorant stubborn child that teaches you, I can admit that I see that you seem to know a lot about audio tech. I read a bit through that article and yes, there's a lot I don't understand. But on this forum one's background simply doesn't matter. None will take your audibility claim seriously unless you perform blind testing.
And then you will realize how truely difficult it actually is to hear anything.

[twistedddx]

i'ld love to hear if all the people(even if most) of the guys that say dvd-a/sacd has nothing over cd audiowise have actually got any equipment to test it with?

I'll invite you round my house and we can do blind tests for hours

my setup is:
denon dvd-3910 (upgraded to 3rd gen denon link linked with latest firmware A)
denon avr-3805
vaf dc-x/7/6 speakers

Adelaide, Australia... bring your own content or I'll suplly my own