Solutions for True Peak / Intersample Peak limiting that really work?

[Alexey Lukin]

Originally Posted by espasonico

I mean, if you limit a peak of 3dB, then, the intersample peak is gonna be around +3db ?

No.

[rhythminmind]

You don't have to worry about inter-sample peaks. We are talking about a +20 work environment here (it's not a music master). If your peaks are hitting the network peak limit & your mix is at the industry average of -24 LKFS, Something is wrong with your mix. That would be one hell of a dynamic peak & should be controlled.

FYI - You can set your DDM to read "true peak".

[oldeanalogueguy]

Originally Posted by Alexey Lukin

You are probably right. Unfortunately, since in some special cases these analog peak levels can go very much beyond digital peak levels, these "properly designed" converters most likely do not exist.
And mastering is all about making recordings sound good on real-world playback systems, not on some ideal systems.

i say that they do -
and the problem is elsewhere
(unless you also have a poorly done d/a system)

analog "peak" always goes higher than most digital samples (would have been if that had been the original sampled analog signal)
that is just nyquist law in action
i can show examples where they can go 60dB and even higher

like i said earlier
use minimum samples eg 2x+epsilon you will have problems
but oversample 10-20x or more and the problem goes away

now if you do nonlinear processing (compress, clip, limit, yada yada) you need to low pass filter the digital before sending it to teh d/a
or else nyquist theorem will not apply

why not lower the digital level
and boost it after d/a if you want a louder signal ?

this so called problem should be fixed in the analog domain where you can control it (and see it precisely)
trying to do it in the digital domain with invalid signals is like pushing on a rope

[Alexey Lukin]

Sorry, this doesn't make any sense to me.

[oldeanalogueguy]

Originally Posted by Alexey Lukin

Sorry, this doesn't make any sense to me.

i do believe that you do not understand it
it would be worthwhile for you to try to figure it out

there may be a problem
i believe some people have a problme
BUT
it is not any alleged intersample peak problem
that may be a symptom that is misinterpreted
it is not a problem
and certainly not the root cause of the problem

badly designed d/a converter system may be a problem

non linear processing that negates nyquist theorem is a problem

people who dont know what they are talkign about but just parrot every bit of wizdumb they read on the internet is a problem

[rcutz]

Maybe it can help:

Level Practices (Part 1)

Level Practices (Part 2) (Includes the K-System)

best.
rcutz

[kk@jamsync.com]

Originally Posted by oldeanalogueguy

i do believe that you do not understand it
it would be worthwhile for you to try to figure it out

there may be a problem
i believe some people have a problme
BUT
it is not any alleged intersample peak problem
that may be a symptom that is misinterpreted
it is not a problem
and certainly not the root cause of the problem

badly designed d/a converter system may be a problem

non linear processing that negates nyquist theorem is a problem

people who dont know what they are talkign about but just parrot every bit of wizdumb they read on the internet is a problem

Pardon me for being blunt, but where are your real-world apps that assist us in making a living and why don't you use your real name here? It's getting irritating reading a discussion that seems to be drifting into troll territory.

[minister]

Originally Posted by kk@jamsync.com

Pardon me for being blunt, but where are your real-world apps that assist us in making a living and why don't you use your real name here? It's getting irritating reading a discussion that seems to be drifting into troll territory.

Drifting?

He provides no proof what so ever of his views, only convoluted hard to understand reasoning based on decades old research. Yet he attempts to take to task TC Electronic for merely making assertions. Nielson and Lund's papers are filled with examples and explanations what warrant the assertability of their positions. He provides nothing but smoke screens.

Paul Frindle, designer of the Oxford Console's DAC, acknowledges the reality of and tries to educate us about Intersample Peaks. Dan Lavry who designs his own DAC aknowledges the problem. Other designers currently working on yet to be released DAC's acknowledge the issue. Alistair, who clearly knows his digital theory, explains it to him. Alexey Lukin, who is both learned and very smart as well as a designer, provides him with clear examples and proof. And yet, Oldeanalogueguy even recommends to newbies that they read what is in his view a "good book" on Mastering, citing the Bob Katz's Mastering Audio. In Katz's book he talks about it, you can find it in the index. Even on Digido.com (Bob's Website) there is an article about it!

Drifting?

Here are a couple of links for the curious:

http://www.digido.com/more-bits-please.html

Scroll down the page for Dan Lavry's response here:

http://recforums.prosoundweb.com/index.php/t/4140/0/

Do inter-sample peaks only matter during D/A (Mr Frindle?)?

[kosmokrator]

anyone in mastering knows that intersample peaks exist and can actually be a problem for the DACs in consumer equipment.

If you want to get rid of them, the BW2-limiter in the S6000 is a good option. Many post-facilites will have an S6000 anyway.
For Nuendo-users there's a free plugin from SSL. On PT I don't know.

[UnderTow]

Originally Posted by oldeanalogueguy

i do believe that you do not understand it

He is just being polite. This has lasted long enough so I won't be: You don't understand digital audio nor are you smart enough to realise your own ignorance. Go away, you are merely a distraction in an otherwise informative technical thread.

Alistair

[philper]

Meanwhile--happy to report that Elephant is containing all the peaks (in 8X) quite well, by my various metering devices (incl LM100).

phil p

[UnderTow]

Originally Posted by philper

Meanwhile--happy to report that Elephant is containing all the peaks (in 8X) quite well, by my various metering devices (incl LM100).

phil p

Oh excellent. Are you using it with the VST-RTAS wrapper?

Alistair

[oldeanalogueguy]

Originally Posted by UnderTow

He is just being polite. This has lasted long enough so I won't be: You don't understand digital audio nor are you smart enough to realise your own ignorance. Go away, you are merely a distraction in an otherwise informative technical thread.

Alistair

i understand digital audio quite well
i also know the crapp,urban myths, what high school seniors know and just plain internet wizdumb that is wrong.

if you can't see the problems with all those references people keep pointing to then you need to go back to school and really learn digital methods this time.

[philper]

Originally Posted by UnderTow

Oh excellent. Are you using it with the VST-RTAS wrapper?

Alistair

Nope, full-strength VST.

phil p

[oldeanalogueguy]

Originally Posted by minister

Drifting?

He provides no proof what so ever of his views, only convoluted hard to understand reasoning based on decades old research. Yet he attempts to take to task TC Electronic for merely making assertions. Nielson and Lund's papers are filled with examples and explanations what warrant the assertability of their positions. He provides nothing but smoke screens.

Paul Frindle, designer of the Oxford Console's DAC, acknowledges the reality of and tries to educate us about Intersample Peaks. Dan Lavry who designs his own DAC aknowledges the problem. Other designers currently working on yet to be released DAC's acknowledge the issue. Alistair, who clearly knows his digital theory, explains it to him. Alexey Lukin, who is both learned and very smart as well as a designer, provides him with clear examples and proof. And yet, Oldeanalogueguy even recommends to newbies that they read what is in his view a "good book" on Mastering, citing the Bob Katz's Mastering Audio. In Katz's book he talks about it, you can find it in the index. Even on Digido.com (Bob's Website) there is an article about it!

Drifting?

Here are a couple of links for the curious:

More Bits Please!

Scroll down the page for Dan Lavry's response here:

PSW Recording Forums: Dan Lavry => intersample peaks

Do inter-sample peaks only matter during D/A (Mr Frindle?)?

rotflamopimp

read the reply at the pro forum
it says its the d/a
and it should be able to handle it
(if designed correctly i note editorially)

[oldeanalogueguy]

thanks to all for the pointers and now
having read the fine literature
my claim has been proven
by those with facts in spite of many unfounded claims

if you have intersample peaks
either your a/d d/a was badly designed
or
you have created an "illegal" signal (ie does not meet nyquist bandlimited criteria) with nonlinear processing which is a stupidity problem not an alleged intersample peak problem

and as one site notes - you are running everything way too hot
in the digital domain which causes other problems - so back off
there are better ways to make things loud
and like Bob Katz said you should make it gooder not louder or something similar to taht

[chap]

was there ever a clear solution to this problem? -24 lkfs? I need to output 13 episodes of concert TV. Any ideas? Thanks. I need to stay within the rigid specs that have been referred to in parts of the thread. Thanks!

chap

[voidar]

G-clip.

Clip at 99%

[Alexey Lukin]

Solution to which problem?

[voidar]

To intersample peaks.

[UnderTow]

Originally Posted by voidar

To intersample peaks.

There are many solutions. What is the context?

Alistair

[GregorioM]

I've seen a few threads on other forums here at Gearslutz where oldanalogueguy has tried to peddle his unique version of digital audio theory.

Oldanalogueguy - You are completely entitled to interpret digital audio theory however you want but you are really out of your depth on this forum because you have absolutely no idea about the workflows or specifications to which we work. In TV broadcast there is a correlation between digital an analogue because this industry works on calibrated systems. And, your discussions about DACs are completely irrelevant, what have DACs (and their architecture) got to do with delivery specifications? This is a serious and very useful thread on the practical implementation of new laws and regulations governing our specific industry, so please go and troll elsewhere.

Now back to our normal programming: Has anyone tried the Compassion Compressor (DMG Audio)? It has the following relevant selectable parameters: Look ahead processing, Oversampling and Brickwall Limiting. In theory this should make it suitable for the task. Anyone tried it?

G

[piratepost]

I've been using The Flux Elixir plugin on my deliverables to satisfy CALM. Works great. TruePeak. Verified with the the Nugen Meter.

Elixir

[Henchman]

Originally Posted by AlexeyMohr

2) we're getting push-back from our mixers for over-limiting their mixes in layback, and I can't blame them. I wouldn't want my mix to be squashed any more than necessary either.

.

I just started reading this thread after it surfaced.

My response to the above, is to tell the mixers to start mixing to spec, and their mixes won't be over-limited and over compressed.

It's part of the gig.

[Paul Frindle]

Originally Posted by piratepost

I've been using The Flux Elixir plugin on my deliverables to satisfy CALM. Works great. TruePeak. Verified with the the Nugen Meter.

Elixir

Yes - I have in intersample peak meter and correcter I use all the time when mastering. We made it some time ago but never got around to selling it, what with all the hassles of 64 bits etc..

Fact is that not only do some DACs mess up - also the SRCs contained within DAC products these days (in more expensive ones) mess up too, even before the signal gets to the DAC!.

Remember also that MP3 coding and decoding (and all other types of perceptual coding) increases peak levels too.

Now you have to be more careful than ever before :-(

[Denis Goekdag]

+1 on the FLUX Elixir, does a great job here.

[YannL]

Indeed Elixir does a great job and is not so expensive. But eats a lot of CPU. It depends the computer and the DAW but hard to use in real time.

[huub]

Originally Posted by rhythminmind

You don't have to worry about inter-sample peaks. We are talking about a +20 work environment here (it's not a music master). If your peaks are hitting the network peak limit & your mix is at the industry average of -24 LKFS, Something is wrong with your mix. That would be one hell of a dynamic peak & should be controlled.

FYI - You can set your DDM to read "true peak".

I agree, I mix live television, the most uncontrolled of environments, and I don't feel the need for a true peak limiter.. I never reach close to -3dBFs, and just for safety I brickwall at -4 or so..

[nkf]

Originally Posted by Denis Goekdag

+1 on the FLUX Elixir, does a great job here.

+1 here too ... it's just that the email support of Flux is really bad. I reported a
problem with Elixir and PTHD 9.05 and got a 'reply' five weeks later to report more in detail ... yeah right ...
Nevertheless I use their Pure Analyzer System and it's very good. Although it has it quirks too but mostly I can work around them. Stopped asking support with that too. Started to see Flux as some being I have no influence on as a customer whatsoever - sad.

[GregorioM]

Paul Frindle and Paradox Uncr8ted:

In TV broadcast we've never been too bothered about inter-sample peaks because the specs we worked to usually resulted in peaks no higher than -10dBFS. The new North American (ATSC A/85) and European (EBU-R128) specifications both specify new peak levels, expressed in true peak, as calculated by compliant meters.

Although of passing interest, we're not really bothered by the fine detail of what happens in the SRC or the reconstruction filters in DACs but our reputations and jobs depend on us being able to measure and confine our mixes to the loudness and true peak levels as measured by meters compliant with the appropriate specification. It maybe, after going into the fine programming detail of these meters that some bright spark notices they don't actually calculate true peak precisely. But to us, that's largely irrelevant, our job is to get through quality control, as determined by some intern running software with the same metering algorithms as we're using. Hence this thread, to discuss limiters which will brickwall limit to the true peak specifications of our meters.

BTW, if you're interested, the tech docs can be found here:
EBU-R128 (website).
ATSC A/85 (pdf)
Both of these are based on the ITU-R-BS1770 specification.

G