Topic: what's the point of recording at 24/192?

[wbrisette]

One more thing +T to everybody for their thoughts on this. This has been one of the more useful discussions about this that I have seen in a long time.

Wayne

[zowie]

Are there perhaps some additional benefits to higher sampling rates for minimizing degradation from post processing?  There are for bit depths beyond 24.

[Lil Kim Jong-Il]

Are there perhaps some additional benefits to higher sampling rates for minimizing degradation from post processing?  There are for bit depths beyond 24.

Are you talking about actual quantization bit depths at greater 24-bit? 

[JasonSobel]

For example, if short pulses are applied to each ear, a 15 microseconds difference between the pulses can be heard, and that time difference is shorter than the time between two samples at 48kHz.  Some people can hear a 5 microseconds difference, and that corresponds to the time difference between two samples at 192kHz.  In theory, this high sampling rate may improve spatial imaging.  Thus, it may take two ears to distinguish between a recording at 48kHz, and one at 192kHz.

that something I hadn't thought about.  +T to everyone who's posted some interesting stuff.  those articles are pretty interesting.

Last Thursday I ran my 4 mics at Cooper's Uncle (local bluegrass band). The QTC-1 mics were on stage clamped just below their mics, thus you have the QTC-1's as the main mics. Then I ran my SR-77 mics at stage lip to pick up the other stuff. I just put this on DVD-A. This was recorded at 24/48.

This Thursday I have told them I would record them again, in the same venue. I'll setup my mics the same way again, but I'll run the DEVA at 24/96. Then burn it on DVD-A as well.

I'll mark the DVD's as 1 and 2 and ship them out to anybody who wants to do a blind test. Then they can tell me which is which... If anybody is up for this, just drop me a line and I'll get you setup.

Wayne

Wayne - I'd be interested in this, thanks for the offer.  question for you.  with your 4 mics and the DEVA, I'm assuming you recorded 4 channels, yes? did you mix it to stereo?  or are you burning surround DVD-audio discs?  I ask, because the only thing I really have to listen to these is my headphones.  (and for this to be truely blind, I'll have to use a notecard to cover up the sample rate lights on the 901.  if I forget to do that, it'll tell me which is which )

In all honesty, I'll probably never run higher than 96kHz but mostly because that is what I can put in an audio-DVD.  I do plan to run a full suite of tests when then 722 gets here.

why can't you put 24/192 onto a DVD-audio disc?  DVD-audio supports 2-channel 24/192, although surround sound only up to 24/96.  (someone please correct me if I'm wrong)

[wbrisette]

Wayne - I'd be interested in this, thanks for the offer.  question for you.  with your 4 mics and the DEVA, I'm assuming you recorded 4 channels, yes? did you mix it to stereo?  or are you burning surround DVD-audio discs?  I ask, because the only thing I really have to listen to these is my headphones.  (and for this to be truely blind, I'll have to use a notecard to cover up the sample rate lights on the 901.  if I forget to do that, it'll tell me which is which )

I'll end up mixing them to 2 channel, primarily because that's all I use. They get mixed later in Digital Performer.

Wayne

[Lil Kim Jong-Il]

In all honesty, I'll probably never run higher than 96kHz but mostly because that is what I can put in an audio-DVD.  I do plan to run a full suite of tests when then 722 gets here.

why can't you put 24/192 onto a DVD-audio disc?  DVD-audio supports 2-channel 24/192, although surround sound only up to 24/96.  (someone please correct me if I'm wrong)

I'll put them to "audio-DVD" using the DVDV format.  DVDV only supports 48k and 96k LPCM.  I don't want to use DVDA format unless I have to because I want discs to play in all DVD players and most of the currently deployed DVD players do not support DVDA formatted discs.  It's easy to confuse the two but "audio-DVD" has become the defacto term for a DVDV disk with just lpcm audio on it.

I got a 24/96 of Ball for chistmas and it plays in all DVD players.  It is reported as DVDV disc in my player, not DVDA.  So apparently this is the way the studios are addressing the compatability issue too.

[Tim]

great stuff here guys, I've been following this one very closely.... +T's to the thread!

[heath]

wayne,
   I would love to hear this.  I'll shoot you a PM...  I have a feeling this test will reinforce my reasoning for running 48 in the field.   

big +t for the offer.  and for that DEVA [drool]

I would love to check out your setup some time 

[wboswell]

In all honesty, I'll probably never run higher than 96kHz but mostly because that is what I can put in an audio-DVD.  I do plan to run a full suite of tests when then 722 gets here.

why can't you put 24/192 onto a DVD-audio disc?  DVD-audio supports 2-channel 24/192, although surround sound only up to 24/96.  (someone please correct me if I'm wrong)

I'll put them to "audio-DVD" using the DVDV format.  DVDV only supports 48k and 96k LPCM.  I don't want to use DVDA format unless I have to because I want discs to play in all DVD players and most of the currently deployed DVD players do not support DVDA formatted discs.  It's easy to confuse the two but "audio-DVD" has become the defacto term for a DVDV disk with just lpcm audio on it.

I got a 24/96 of Ball for chistmas and it plays in all DVD players.  It is reported as DVDV disc in my player, not DVDA.  So apparently this is the way the studios are addressing the compatability issue too.

Very interesting...  I've had issues with my Denon 2900 and DVD-R discs burned as DVD-A in discwelder.  The player will play the discs and output correctly if I use the 5.1 outputs, but when I try to output a digital signal, only the left main channel plays.  However, the player will output a digital signal for store bought DVD-A discs such as Robert Cray's "Time Will Tell"  The packaging says DVD-A but it may actually be DVDV.  FWIW, this album was released by Sanctuary, the same label that WSP's Ball was release under...

That being said, what software do you use to burn to DVDV?

Thanks!

[Lil Kim Jong-Il]

Very interesting...  I've had issues with my Denon 2900 and DVD-R discs burned as DVD-A in discwelder.  The player will play the discs and output correctly if I use the 5.1 outputs, but when I try to output a digital signal, only the left main channel plays.  However, the player will output a digital signal for store bought DVD-A discs such as Robert Cray's "Time Will Tell"  The packaging says DVD-A but it may actually be DVDV.  FWIW, this album was released by Sanctuary, the same label that WSP's Ball was release under...

That being said, what software do you use to burn to DVDV?

Thanks!

I don't use a windows installation for personal computing, so I am currently wasting time trying to get the commandline tools under linux to work but I keep getting periodic static within the DVDs that I have authored using that approach.  I think it has to do with the A/V stream multiplexing prior to authoring step.  I want to get that to work more than anything else. 

I'm not in any hurry to buy SW until the 722 ships, but when that day comes I'm going to buy the audio-dvd-creator.  I know someone here who is using it and he is having success.  This weekend I'm going to try the demo version under wine.  Look in the computer recording forum and there is a ton of info. 

I'm using a 2900 also.  Nice unit.

[Karl]

One thing that I find very interesting is that everybody talks about how superior analog recording can be.  What bit depth and sample rate will it take to convince people that digital can be superior?

[Tim]

One thing that I find very interesting is that everybody talks about how superior analog recording can be. What bit depth and sample rate will it take to convince people that digital can be superior?

from what I've read it's DSD that is finally convincing people that digital can be as good as analog

[zowie]

OK, to get back to the original topic, here are a few excerpts and paraphrases from what Bob Katz says about using high sample rates in Mastering Audio.  (ALL advanced tapers should buy this book!)  This is just to get you the flavor, it doesn't do justice to his 6 page discussion of the topic. 


"[H]ow can 50-year-old ears detect differences between 44.1 kHz and 96 kHz and even 192 Khz sample rates, even though most of us can't hear much about 15 kHz?  I believe the answer lies in the design of digital low-pass filters which are part of the requirements of digital audio.  [ . . .]   One type of filter has a sharp cutoff; the consequences of sharp filtering include time-smearing of the audio, possible short (millisecond) echos wich are caused by amplitude response ripples in the passband frequency response (20 Hz - 20 kHz),  . . .   Moving the filter cutoff frequency to 48 kHz (for 96 kHz sampling rate) relaxes the filtering requirement and makes it easier to engineer filters with less ripple in the passband and less phase shift near the upper frequency limit."


To answer my question:
"Moorer [of Sonic Solutions] pointed out that post-processing, such as filtering, equalization, and compression, will result in less distortion in the audible band [at 96 kHz] as the errors are spread over twice the bandwith -- and half of that bandwidth is above 20 kHz."

"In addition . . if after processing the destiantion is DVD-A or SACD, then the master can be left at the higher sample rate and worklength, avoiding another generation of sound-veiling 16-bit dither and yet another sharp filter at the end of the process.  Thus, consumers should not scoff at DVDs which have been digitall remastered from original 16/44.1 sources.  They will be getting real, audiophile-quality sonic value in their remaserters."

While there would probably be diminishing returns, I [zowie, not Katz] would imagine that the above applied equally to 192 kHz. Katz suggests that 96kHz would perhaps be a minimal sampling rate if there is a redesign in PCM converters to make themer more psychoacoutically correct than they are today.

I would think that higher sampling rate would especially benefit those of us using consumer/prosumer equipment (M-Audio, Edirol, Sony) and software that probably has relatively lower quality digital filters compared to the big dollar rack gear.

[relaxing]

To answer my question:
"Moorer [of Sonic Solutions] pointed out that post-processing, such as filtering, equalization, and compression, will result in less distortion in the audible band [at 96 kHz] as the errors are spread over twice the bandwith -- and half of that bandwidth is above 20 kHz."

I think I understand what he's getting at, but I just want to be clear -- what errors is he speaking of?
Can you provide more context?

[BobW]

192kHz is big for forensics and EFX work, when slowed playback down might occur.
96kHz is definitely discernable, though ever so slightly.  192kHz is deinitely overkill to my ears.

The DAC is much more important, IMHO.