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Marc Wielage

96kHz -- Pros and Cons?

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9 hours ago, Philip Perkins said:

I have a very good friend who is an eminent music engineer and he calls higher sample rate recording "cork sniffing".  I don't hear any diffs in the work I do 48/96 or 44.1/88.2, but I sure feel the inconveniences involved.  But....many people who make decisions about who gets to do what in the music world ARE convinced that 88.2/96 is better, AND that it is a marketing tool.   Serious music buyers, esp in the classical etc world are a SNOOTY bunch, they do not want music that just anyone can buy ( I guess) so the extra added attraction of "recorded at 96k" (or higher) is kind of like "extra-bitchen virgin vinyl" in LPs etc.  I decided that if my peeps thought it would sell more albums I'd do it, so when they do I go 96.

While I tend to agree with what you're stating it strikes me as interesting that the bandwidth debates precede digital audio and the relevance of frequency response out side of human hearinghas been topic of many discussions in the analog past. Take this example of a conversation with Rupert Neve with the understanding that this has very little to do with what's being discussed here or what we do for a living on a day to day basis.

Quote

Fletcher: There has been some measure of debate about bandwidth including frequencies above 20 kHz, can we hear them, do they make a difference, etc.

Rupert Neve: OK, Fletch, pin your ears back… In 1977, just after I had sold the company, George Martin called me to say that Air Studios had taken delivery of a Neve console, which did not seem to be giving satisfaction to Geoff Emerick.

In fact, he said that Geoff is unhappy…. engineers from the company, bear in mind that at this point I was not primarily involved, had visited the studio and reported that nothing was wrong. They said that the customer is mad and that the problem will go away if we ignore it long enough.

Well I visited the studio and after careful listening with Geoff, I agreed with him that three panels on this 48 panel console sounded slightly different. We discovered that there was a 3 dB peak at 54 kHz Geoff’s golden ears had perceived that there was a difference.

We found that 3 transformers had been incorrectly wired and it was a matter of minutes to correct this. After which Geoff was happy. And I mean that he relaxed and there was a big smile on his face.

As you can imagine a lot of theories were put forward, but even today I couldn’t tell you how an experienced listener can perceive frequencies of the normal range of hearing.

And following on from this, I was visiting Japan and was invited to the laboratories of Professor Oohashi.

He had discovered that when filters were applied to an audio signal cutting off frequencies of 20 kHz, the brain started to emit electric signals which can be measured and quantified.

These signals were at the frequencies and of the pattern which are associated with frustration and anger. Clearly we discussed this at some length and I also would forward the idea that any frequencies which were not part of the original music, such as quantizing noise produced by compact discs and other digital sources, also produced similar brain waves.

 

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13 hours ago, shaneconnelly said:

What about final delivery formats? I believe the audio tracks for blue ray discs are 96k. Not sure about digital cinema.. So at some point the 48k files have to be up sampled and that may not be good for the integrity if the audio.

DCP is 48k

2 hours ago, Werner Althaus said:

Take this example of a conversation with Rupert Neve with the understanding that this has very little to do with what's being discussed here or what we do for a living on a day to day basis.

Rupert Neve told me this very story when I met him in 1995... 

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There is a case to be made for 96kHz in live situations.   Digico desks running at 96kHz are popular (>50% at varsity level concerts)

Reducing Latency is one, as there are multiple points in the signal chain that add latency back.

Cleaner EQ curves is another. The math in Digital mixers warps the frequency response of the EQ, moreso at higher frequencies, so the higher FS makes the curve sound more like its analog original.  

Re-sampling from one rate to another can be done abritrarily good as an offline process, easily maintaining 24 bits of dynamic range and noise floor. The math and processing power to do this wasn't available early on during the digital audio renaissance, so some still think re-sampling is bad.  There is one slight gotcha there though - intrasample peaks.  If the source file was a mastered song, it may already have samples peaking close to 0dBFS, so when properly re-sampled, you get new samples that peak above 0dB which will then the truncated as a result of saving the file.  Played back normally, the original creates those intra-sample peaks in the D/A converter chip, which is designed to handle them.

That's one of the benefits of DSD I lilke to explain: it has an upper limit of +6dBFS, although it is normal never to go above +3dBFS, i.e. remastered songs don't need transient smearing brick-wall limiting at the end.

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I find myself the recipient of the end of this discussion on a fairly regular basis.  I am only recording music, almost all classical acoustic, nowadays and for 100% of the "location live" recordings that I do, even for broadcast are at 44.1/24. No question that the ambience of a live space will completely undo any perceived benefit of a higher sampling rate and my clients, all musicians or broadcast producers, are aware of that and fine with it.

Where I get requests, no, demands for 88.2/24 are on actual recording sessions, where every one of those producers will not consider 44.1. Since they are my bosses, I happily aquiesce.  No sweat off my nose, easy!  (This is except for trying to build up a Dante rig where manufacturers fall way behind on Dante at 96k which is a big problem for me right now.  Still haulin' around a heavy copper snake to feed the control room. Bah!)

Whether they, mastering houses, vinyl or CD pressers or the audience can hear the difference that the higher sampling rates is of no concern to me.  My clients simply get what they ask for.

Oh and BTW, 96k for dialog is simply ridiculous, IMHO. RIDICULOUS!  It really puts the posties in a bad place as Marc so eloquently explains.

D.

 

 

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16 hours ago, shaneconnelly said:

What about final delivery formats? I believe the audio tracks for blue ray discs are 96k. Not sure about digital cinema.. So at some point the 48k files have to be up sampled and that may not be good for the integrity if the audio.

DCP is 48k

NOT to say whether 96k is ridiculous for film or not- but

Avid Media Composer and even DaVinci Resolve can do 96k now. PT can do 96k and has been able to for a long long time. 

-vin

 

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Once 192Khz became available on production sound recorders, all of us in the sound effects recording/sound design world used it and it was/is very helpful for sound design. I could do things with a 192Khz file that I couldn't do with a 48Khz file...mainly avoid artifacts and the like once heavy sound design starts happening. For basic stuff, like backgrounds, or hard effects that don't require a ton of manipulation, the higher sample rate doesn't matter, but you never know what your recorded sound is going to be used for, so we'd always record at the highest sample rate possible. 

For production dialogue, it is completely un-necessary. I can't hear the difference between dialogue recorded at 48Khz and 96Khz, and I don't know anyone who can. In the post world, time is money, and the less time spent moving files around, converting them, and doing whatever else needs to be done to make them workable the better, especially in the reality world. When I was on a reality TV show cutting effects, we'd sometimes be given an episode to start cutting sound on that was supposed to be on the mix stage two days ago (because they kept going through picture editors and changing the picture edit...that's another story). I wouldn't want to have to deal with file conversions when I'm supposed to be cutting and only have half a day or a full day to get the entire job done. 

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I've heard of a few voicover projects where 96k was specified specifically because the plan was to do sound design style processing and pitch shifting to several of the characters as a whole.  

That seems like the only reason to run 96k on set as well.  

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16 hours ago, rcoronado said:

I've heard of a few voicover projects where 96k was specified specifically because the plan was to do sound design style processing and pitch shifting to several of the characters as a whole.  

That seems like the only reason to run 96k on set as well.  

Well there's the very real issue of time stretching and pitch shifting with both ADR and dialogue editing of alts, but on the other hand I'd rather put up with crappy artifacts than a 96k workflow through editorial!

J

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There are even times when aliasing can be a useful part of sound design.

I used to keep a copy of SoundEdit16 (on an ancient System 7 Mac that could run it). It was too early and underpowered to use oversampling, and they didn't bother to do additional filtering when lowering the s/r or varispeeding. But when you wanted harsh, non-musical upper octaves on a monster or weird machine, it was great.

(On the other hand, it was at the same time that I discovered the Nubus Digi card that came with early ProTools and Avid didn't change its filters when recording at lower sample rates. If you were doing a multimedia project that required lots of 22k s/r voice files, you had to record at 44.1 and convert. If you recorded at 22.050 s/r, the ADC's input filter was still at 19k and even normal voices would alias.) 

 

 

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On 10/20/2016 at 7:31 AM, shaneconnelly said:

What about final delivery formats? I believe the audio tracks for blue ray discs are 96k. Not sure about digital cinema.. So at some point the 48k files have to be up sampled and that may not be good for the integrity if the audio.

DCP is 48k

2 hours ago, The Immoral Mr Teas said:

Well there's the very real issue of time stretching and pitch shifting with both ADR and dialogue editing of alts, but on the other hand I'd rather put up with crappy artifacts than a 96k workflow through editorial!

J

why is there any issue with 96k in edit- Avid MC, Davinci Resolve both take 96. 

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Yep I guess it comes down to post then delivery formats and if the punters can tell the difference!

Also I guess 96K will help collect more HMI noise starting at 19K etc

mike

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On 2/6/2008 at 0:52 PM, miker71 said:

 

"... some recent research ."

Which research ? I would like to read this research. Is there a name, or a link ?

 

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One thing to keep in mind re: sample rates in the field -  AFAIK, the highest rate offered by wireless systems is 48k. The only place you'd actually get frequency content in excess of  @ 24 kHz is a hard wired mic. 

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One thing to keep in mind re: sample rates in the field -  AFAIK, the highest rate offered by wireless systems is 48k. The only place you'd actually get frequency content in excess of  @ 24 kHz is a hard wired mic. 

That could be a reason to not use digital wireless

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21 minutes ago, Constantin said:


That could be a reason to not use digital wireless

For dialog? What content would you need above 24 kHz for human speech and basic everyday noises (footsteps, etc)?

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For dialog? What content would you need above 24 kHz for human speech and basic everyday noises (footsteps, etc)?

That wasn't my point. You were saying that radio mics aren't capable of anything higher than 48k, and I was implying that with analog radio mics they might be able to. Although most if not all radio mics, analog or digital, are probably not able to transmit any frequency content above 20k.

Anyway, it was a kind of a joke

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Great discussion folks.

When I started my career I had my ears checked and was judged to have the hearing of a child!

Now many years later I'm down to 10kHz but my sensitivity and ear/brain (monitoring ability) is great.

I once questioned why use of noise reduction for Nagras was not more common and the answer was that

despite tape noise plus reasonably low print through with Scotch 808 most locations were noisier than

our analog equipment anyway, and did we use 7.5 ips or 15 ips for dialogue?

Ultimately what systems are our hard work listened on - cinema/DVD/TV - hardly stringent monitoring.

As for hi-fi freaks, are they listening to their equipment or to the music and the performances?

48k and 96k is a circular issue just like CD and vinyl and it will long continue.

mike

Edited by mikewest
Additional question

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