R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [3] 4 5 ... 7   Go Down

Author Topic: Removal of ITB Slew  (Read 14517 times)

AndreasN

  • Full Member
  • ***
  • Offline Offline
  • Posts: 247
Re: Removal of ITB Slew
« Reply #30 on: August 02, 2006, 03:45:18 AM »

chrisj wrote on Tue, 01 August 2006 17:44


Yes, it's intersample peaking that causes sounds like high percussion to distort before 0 db. No, oversampled peak metering doesn't address the problem- it helps you avoid the problem, which is different.


Sorry. A syntax error. Avoiding the problem is easily done by watching an oversampling peak meter, was what I meant to say.  

I don't even now how to search for slew in an audio file, but peak meters are quite easy enough to use. =)

Checking for maximum slew rate after all digital processing does not reveal when the problem starts in the first place. Or how much this have a potential to affect consumer systems; if it's a zero dot something small dB overshot or a square wave filtered down to +3dBFS sine wave.

Quote:

This IS the secret of a good A/D converter, because when you go hot and bright into a good A/D converter, there's an antialiasing filter that does exactly this- control the reconstructed wave  and produce a set of samples that would correspond to an output wave that does not overshoot...


Hmm... I thought AD's was inherently immune against creating illegal sample values on their own..?

Take a 11026Hz sine wave. It should clip the AD at the same analogue voltage regardless of the sine wave phase at the sampling instance, even though the digital numbers will vary by about 3dB as the sine peaks and troughs beats against the sampling frequency.


cerberus wrote on Tue, 01 August 2006 19:05

i think chris' article describes an intersample peak phenomenon; not every one.


What other means are there to create intersample peaks?

Quote:

 but imo, we are kinda leaning towards audipophiles here, wheras most consumers may like this kind of distortion.


What distortion? It's a big unknown. Just how the distortion will sound in the particular piece of equipment the consumer use can not be known. That's the nasty thing about it.


Andreas
Logged

ericjenson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 218
Re: Removal of ITB Slew
« Reply #31 on: August 02, 2006, 05:01:51 AM »

i suppose this comes way too late in the discussion, but how does one search for the maximum slew rate in a file?  
what tools are used?

and i'm having trouble understanding the application of an oversampled peak meter, i mean, i know the concept, but how does this tool help in this situation?

where can i find such tools?

please and thank you

because i've just been zooming in using wavelab and there they are, high acceleration, distortion causing slew rates.
detectable by the thousands in one track off of any given commercial CD.


oh, except for the "audiophile" quality CDs.


ok, here's another thing, and it's starting to really bug me...
in a major way...


what is wrong with a mastering engineer being an audiophile?!!
............................................................ ..
.........

really, what is the basis of this objection i keep reading from numerous posters?

lemme catch my breath, cause this is makin me red freakin hot...

trying to control myself..

ok..

are we not in the business, as mastering engineers, of helping in the production of high quality audio for our consumers, (many of whom are "audiophiles" themselves)?
or are we just in it for the money, and "audiophiles" are a seperate bunch of geeks, much like ourselves, who are addicted to pristine audio sounds, and we the pushers of "cut", fake, psychoacoustic, but not the "real" thing?
not the "good stuff"?

no, the "good $hit" we keep to ourselves..

we'll just print this CD now because it's good enough for "them"

...
this attitude, and forgive me if i'm misinterpreting,
but this kind of attitude makes me want to literally start destroying things, it makes me violent...
i don't consider this to be a personal problem because i think it's very justified.

i'm passionate about what i do,
very!!!

so does this make me an "audiophile"?

any input would be appreciated, seriously..
cause sometimes i start to get the feeling i'm hanging out on the wrong forum.

this is very technical stuff,
and i get raving mad when someone who hasn't even read what i'm talking about comes back to belittle my situation and obviously has no idea what i'm talking about.

but alas , this is a public forum..

let the village idiots have their space too.

Quote:

Wouldn't a single jump between two adjacent samples be a thing that is happening for a period of 1/44100:th of a second? What's that - pico, nano, millimicro? Sombrero?



yeah man,

i'm talkin about sombreros dude.
it's really important you wear one while mastering, didnt you know, it's the "way", dude!
don't forget your sombreros everyone, cause that's the secret of good mastering skills.

because, like, the sound waves bounce off the tip of the hat you know,... and like it affects the way the trajectory of the sound wave enters your ears, maan! so it's like way far out ther, man...

but the thing is , dude,

like everyone who hears your masters has to be wearin one too, for it to sound good, so it's like Wahay! COOL man.

a sea of sombreros to hear what you've done, it's like so cool dude, like i just don't know what to say.

...
Logged
Eric Jenson
Mastering Engineer
Acoustics Engineering Apprentice

Patrik T

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 833
Re: Removal of ITB Slew
« Reply #32 on: August 02, 2006, 06:38:30 AM »

Clearly I must insert a lot of these wankers:  Smile  Very Happy  Smile  Very Happy
Otherwise you won't spot humor, will you?

Sombrero:  Smile

Think of it. A big F***ing hat. Hilariously funny in gusty winds. Funny even in calm weather. It's a BIG hat!

But, since I now have read the...what...fourth, fifth post that swing out in moomoo-land and is about "me, me, me" rather than the subject, I think there is little hope for you to shine up a tiny bit or two.

Best Regards
Patrik
Logged

HansP

  • Full Member
  • ***
  • Offline Offline
  • Posts: 165
Re: Removal of ITB Slew
« Reply #33 on: August 02, 2006, 06:46:44 AM »

>i suppose this comes way too late in the discussion, but how does one search for the maximum slew rate in a file?
what tools are used?<

pedestrian formula:
copy the file into 2 tracks of your DAW.
shift a track 1 sample back (there should be a tool available that yields the virtual effect of this).
subtract the two and observe the waveform/levels.
find a plugin that can derive an envelope from this. "rectifying" would be the best approach in this case. shift the envelope 1 sample forward.
with the envelope you can automate lowpassing, interpolating or whatever. a threshold function is recommendable.

--
to the client, the mastering engineer is a bit of a doctor. he has some authority and can cure little problems, or will recommend different behavior.
but medicine has live-saving standards and laws to observe. audio has just math and ear.
in audio there are countless genres and tastes, and eventually everything is sorted out by commercial success and the demands of the clients (who won't afford to crowd the technician when they lack of success).


Logged

ericjenson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 218
Re: Removal of ITB Slew
« Reply #34 on: August 02, 2006, 06:55:06 AM »

Quote:

pedestrian formula:
copy the file into 2 tracks of your DAW.
shift a track 1 sample back (there should be a tool available that yields the virtual effect of this).
subtract the two and observe the waveform/levels.
find a plugin that can derive an envelope from this. "rectifying" would be the best approach in this case. shift the envelope 1 sample forward.
with the envelope you can automate lowpassing, interpolating or whatever. a threshold function is recommendable.


thx for something useful, much appreciated.

i think ozone has something called intersample peak detection correction or something , is this doing the same thing as limiting the slew rate?
Logged
Eric Jenson
Mastering Engineer
Acoustics Engineering Apprentice

ericjenson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 218
Re: Removal of ITB Slew
« Reply #35 on: August 02, 2006, 07:33:11 AM »

Quote:

Think of it. A big F***ing hat. Hilariously funny in gusty winds. Funny even in calm weather. It's a BIG hat!

But, since I now have read the...what...fourth, fifth post that swing out in moomoo-land and is about "me, me, me" rather than the subject, I think there is little hope for you to shine up a tiny bit or two.



i still have the ability to laugh.

and yeah my posts are about me as your posts are about you; because it is you and i who are writing them, correct?

regardless.

without music or my kids i would have nothing to live for.

music is emotion, power, anger, sadness, playful, the whole spectrum. the SPICE.

the beauty of the synthesis of what we do is this:
taking emotion and using technology to deliver that emotion in the form of sound.

two seeming opposites: cold and lifeless digital bits;
but riding on this bitstream is the emotion, the impact of the piece.

do i seem too serious or philosophical?

i take it seriously.   otherwise lets just lock a bunch of chimps in a room with some gear and feed a line of audio through some speakers and let them do with the knobs what they will;
record the output, package, sell...
Laughing
there, i laughed.

how can a post be off topic if all knowledge is related?

i need to take off my thinking sombrero and get some sleep, before the guys in white coats come again,  it's either that or brew another pot and spend another 14 hours listening to music.
or take my dog for a walk, or all of the above if possible.


yeah, my posts are about me..
and i certainly wouldn't want someone else to write them for me.
maybe someone is?
in fact from now on maybe i'll just post as if i'm talking to myself.

wouldn't that be fun.
after all:

i wouldn't want to get too serious about anything, like learning or asking or knowing, no.

life is a game of tetris and i'm just some geek sitting in my basement trying to avoid getting caught up in the matrix. Rolling Eyes

how's that for off topic, all about me baby!.... Twisted Evil


now how about them slew rates?
Logged
Eric Jenson
Mastering Engineer
Acoustics Engineering Apprentice

HansP

  • Full Member
  • ***
  • Offline Offline
  • Posts: 165
Re: Removal of ITB Slew
« Reply #36 on: August 02, 2006, 08:28:34 AM »

>i think ozone has something called intersample peak detection correction or something , is this doing the same thing as limiting the slew rate?

the first would be more exact.

but when you control slew rate it is less likely to get intersample overs.
Logged

cerberus

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2651
Re: Removal of ITB Slew
« Reply #37 on: August 02, 2006, 08:38:19 AM »

HansP wrote on Wed, 02 August 2006 08:28

ericjenson wrote

i think ozone has something called intersample peak detection correction or something , is this doing the same thing as limiting the slew rate?


the first would be more exact.

but when you control slew rate it is less likely to get intersample overs.

to be clear: what you refer to in ozone is oversampled metering; which could lead to more accurate peak detection.

jeff dinces

cerberus

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2651
Re: Removal of ITB Slew
« Reply #38 on: August 02, 2006, 08:53:24 AM »

AndreasN wrote on Wed, 02 August 2006 03:45

What other means are there to create intersample peaks?

 maybe

how about

downsampling?

but no. one doesn't "create" intersample peaks. they exist; whether one acknowleges them or not.

ericjenson wrote

 so does this make me an "audiophile"?

relax man, it's like how people of color sometimes greet each other on the street : "yo, n-----!" we can greet each other like: "yo, audiophile!" but no one else should call us that - very bad word!

Patrik T wrote on Wed, 02 August 2006 06:38


Sombrero:  Smile
have any of you ever seen christmas in sweden? the women wear fully lit candelabras on their heads! (and sing quite beautifully at the same time) i kid you not!


jeff dinces

ericjenson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 218
Re: Removal of ITB Slew
« Reply #39 on: August 02, 2006, 09:07:41 AM »

the ozone manual reads something like:
enable the inter sample peak correction to limit any overs that might be created by conversion back to analog.

how are they calculating this?
if this is done by an oversampling meter, by how much are they oversampling?
and i still don't think i fully understand what an oversampling meter is doing.just what it says?

if so, how does oversampling recreate the conversion back to analog accurately enough to detect any possible overs?

tia in advance for any info

for now i guess i'm gonna google some more.
Logged
Eric Jenson
Mastering Engineer
Acoustics Engineering Apprentice

UnderTow

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 393
Re: Removal of ITB Slew
« Reply #40 on: August 02, 2006, 09:22:39 AM »

ericjenson wrote on Wed, 02 August 2006 10:01


what is wrong with a mastering engineer being an audiophile?!!



That depends of the description you use. Originaly it meant someone that is passionate about sound quality but it has gotten a new meaning: Someone that doesn't understand the principles at work and will spend small fortunes on "snake oil devices" that can not possibly improve sound quality but will ignore real stuff, like accoustics, that will have a guaranteed effect on sound.

These days the word audiophile is often used to describe the later rather than the former. I think it was used in this sense.

Alistair
Logged

Patrik T

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 833
Re: Removal of ITB Slew
« Reply #41 on: August 02, 2006, 11:03:15 AM »

Here's a link to the philosophies of a recording label that is working purely from an audiophile aspect. It can perhaps bring some refreshment into what the term is supposed to mean when it is related to audiophile production/recordings:

http://www.opus3records.com/phil.html

Best Regards
Patrik
Logged

Patrik T

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 833
Re: Removal of ITB Slew
« Reply #42 on: August 02, 2006, 11:20:42 AM »

cerberus wrote on Wed, 02 August 2006 13:53



have any of you ever seen christmas in sweden? the women wear fully lit candelabras on their heads! (and sing quite beautifully at the same time) i kid you not!

jeff dinces


Actually, that is the 13:th of december each year. Anyway, it's one of the most beautiful things on earth. Who would not fall in love seeing something like this at a dark december morning?

http://www.sweden.se/templates/cs/Event____13628.aspx

Sorry for the OT.  Smile

BRGRDS
Patrik
Logged

chrisj

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 959
Re: Removal of ITB Slew
« Reply #43 on: August 02, 2006, 12:18:55 PM »

What fun is it being cool if you can't wear a sombrero? Very Happy

What you do about excessive slew turns out to be tricky indeed. I've tried to use it as a 'distance knob' and excessively limit the slew in various ways, and few things sound as nasty Smile

The easiest thing is just to restrict the maximum slew, so the signal for that sample won't 'go as far'. This could be done by taking Hans' formula, deriving the 'subtracted' version, clipping it at a certain point and then adding it back. It will sound nasty at high levels of limiting.

What I ended up doing is tracking and limiting not the slew itself but the rate of change, on the reasoning that a 'tick' is a very high rate of change first one way then the other. If not for this algorithm, my experiments in WUMP with buggy HF equalization would have sounded even worse Very Happy

Ronny

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2739
Re: Removal of ITB Slew
« Reply #44 on: August 03, 2006, 01:11:14 AM »

Patrik T wrote on Wed, 02 August 2006 11:20

cerberus wrote on Wed, 02 August 2006 13:53



have any of you ever seen christmas in sweden? the women wear fully lit candelabras on their heads! (and sing quite beautifully at the same time) i kid you not!

jeff dinces


Actually, that is the 13:th of december each year. Anyway, it's one of the most beautiful things on earth. Who would not fall in love seeing something like this at a dark december morning?

http://www.sweden.se/templates/cs/Event____13628.aspx

Sorry for the OT.  Smile

BRGRDS
Patrik



I had a Swedish client that visited me when he brought his family to the US for vacation a few Christmas' ago. I took them around to check out the homes with the more extensive x-mas light setups and they were talking amongst themselves in Swedish, which I didn't understand. I asked him what they were talking about and he said that their impression was that the homes in the US were way too gaudy with the Christmas lights and displays. I said Christmas in the US has turned into a holiday for retail outlets.

Ok, sorry for the OT as well, but thought I'd mention that as you mentioned the candlabra hats in Sweden and they seemed kind of gaudy to me.  Laughing

Back to the ITB slew, which still confounds me in the ITB sense, as I can't seem to associate it without an analog amplifier in the equation.
Logged
------Ronny Morris - Digitak Mastering------
---------http://digitakmastering.com---------
----------Powered By Experience-------------
-------------Driven To Perfection---------------

Pages: 1 2 [3] 4 5 ... 7   Go Up
 

Site Hosted By Ashdown Technologies, Inc.

Page created in 0.074 seconds with 16 queries.