Yet another thread on level metering

I don't ever watch the meters...I'd forget what I'm doing if I started looking at stuff... :D
 
After reading the whole first page of that ProSound thread, it just depresses me how many people there are in this racket who have no idea what they're talking about when it comes to levels and metering. Everybody dances around the subject, but nobody in that thread really addresses what is going on.

Yeah OF COURSE the digital meters in editing software are translating samples, not analog signal. That's all downstream of the converter so there is nothing BUT samples at that point. That's why it's called DIGITAL :D. That's what digital IS.

That's also why the units of measurement are different. dBFS is used at that point because it's the best way to represent digital values; VU meters are no longer the most appropriate way to gauge the signal at that point. Not because digital samples are digital samples and analog levels are analog levels, but because

- a) once you are fully in the digital realm, the 0VU reference - representing +4dBu - is no longer an important threshold; it's just another point in the digital continuum no different than any other, and

- b) the purposely slow ballistics of the VU metering standard do not respond fast enough to respond to (a minumum of) 44,100 different volume levels per second.

The underlying problem is not the digital meters reading "samples, not signal". The underlying problem is that very few people seem to understand gain structure in general and that

- both meter types (optionally along with PPM metering) are really rather ideal for their sections of the signal chain,

- that they are measuring the same general thing thing in different ways with different numerical values. Even though one is dealing with analog voltage and the other is dealing with digital samples, they still represent the same actual source voltage equivalents, and

- the key to understanding all of that and the idea of gain structre overall, is to understand what the translation value between the analog VU signal and the digital dBFS reading is in your signal chain. That requires knowing the calibration of the VU meters on the analog side and the calibration level of the A/D converters in your chain, using the dBu measurement scale as the rosetta stone.

All the rest of the discussion is at best, derivitave, and at worst, off the mark.

G.
 
i usually mix with my eyes. i turn the speakers all the way down, then adjust all the faders in-the-box until all the meters are just below clip, then i slap a limiter on the master track and crank the threshold down until the master meter doesn't move at all, it's just pegged at -.01...after this step, it's best to send your mix to a professional mastering house for the final touches.

also i EQ all my tracks visually, with a 10 band EQ plugin (still leaving the speakers off). i use the same EQ curve that everybody with an equalizer uses on thier home stereo, with the highs and lows boosted and the mids cut in kind of a U shape. then i put a compressor on behind the EQ and turn down the threshold until the "gain reduction" light is constantly on.

i find that mixing with your eyes is the best way. YMMV.
 
Glen, something that my little brain can't grasp is how using plugins as to subtract can actually cause clipping. I tried the test mentioned in the PSW thread. White noise generated at -6dbfs, lowpass at 20khz applied, the level jumps up a few db. Next white noise generated at -2dbfs, same lowpass, the level goes up but doesn't trigger the over light. The plugin is acting like a limiter? Someone in the PSW thread mentioned that this involves phase and/or but he didn't elaborate.

SouthSIDE Glen said:
After reading the whole first page of that ProSound thread, it just depresses me how many people there are in this racket who have no idea what they're talking about when it comes to levels and metering. Everybody dances around the subject, but nobody in that thread really addresses what is going on.
Click to expand...

I thought that was what happened here more often than not. :D I've come across some good posts here on the subject but it mostly comes across to me as misunderstood regurgetated babble.
 
zed32 said:
i usually mix with my eyes. i turn the speakers all the way down, then adjust all the faders in-the-box until all the meters are just below clip, then i slap a limiter on the master track and crank the threshold down until the master meter doesn't move at all, it's just pegged at -.01...after this step, it's best to send your mix to a professional mastering house for the final touches.

also i EQ all my tracks visually, with a 10 band EQ plugin (still leaving the speakers off). i use the same EQ curve that everybody with an equalizer uses on thier home stereo, with the highs and lows boosted and the mids cut in kind of a U shape. then i put a compressor on behind the EQ and turn down the threshold until the "gain reduction" light is constantly on.

i find that mixing with your eyes is the best way. YMMV.
Click to expand...

i hope you're making a funny. :p
 
one of the things i like about Reaper is that you can customize the appearance of the meters. if i want a brighter sound, i'll set the upper portion of the meter to a bright white, and adjust the volume until the track is pegged in the white section. for a warmer sound, i use maybe a pale yellow or tan. and for a dark tone, it really depends, but i prefer a dark reddish color (like on Arizona State's uni), or sometimes a dark burnt orange.
 
zed32 said:
i usually mix with my eyes. i turn the speakers all the way down, then adjust all the faders in-the-box until all the meters are just below clip, then i slap a limiter on the master track and crank the threshold down until the master meter doesn't move at all, it's just pegged at -.01...after this step, it's best to send your mix to a professional mastering house for the final touches.

also i EQ all my tracks visually, with a 10 band EQ plugin (still leaving the speakers off). i use the same EQ curve that everybody with an equalizer uses on thier home stereo, with the highs and lows boosted and the mids cut in kind of a U shape. then i put a compressor on behind the EQ and turn down the threshold until the "gain reduction" light is constantly on.

i find that mixing with your eyes is the best way. YMMV.
Click to expand...

LMAO.
Great joke!

Eck
 
TravisinFlorida said:
Glen, something that my little brain can't grasp is how using plugins as to subtract can actually cause clipping. I tried the test mentioned in the PSW thread. White noise generated at -6dbfs, lowpass at 20khz applied, the level jumps up a few db. Next white noise generated at -2dbfs, same lowpass, the level goes up but doesn't trigger the over light. The plugin is acting like a limiter? Someone in the PSW thread mentioned that this involves phase and/or but he didn't elaborate.
Click to expand...
I'm not sure if I'm interprenting Frindle correctly, because some of his terminology use is a bit vague, but it sounds to me like what he's actually talking about is intra-sample clipping.

He keeps talking about the signal coming "out" of a digital mixer, "DAC" - meaning digital to analog conversion, and not vice versa - and "reconstruction", which I assume means the synthesis of a smooth analog signal out of discrete digital samples.

All that, with the inclusion of the random noise generation as his "worst-case test", seems to me that he's saying that running a digital signal close to 0dBFS risks the chance of getting a too-hot signal when going back out to analog because the DAC is going to try to "reconstruct" an analog waveform that may have intra-sample peaks (peaks that exist in that short period of time between digital samples) that would exceed 0dBFS.

In other words, I don't believe he's saying that you'll clip within the editor by doing that, but rather that you chance over-gaining in the DAC when coming out to analog.

If that's indeed what he is talking about, that's not an untrue statement. But there he's talking about post-tracking or mixing gain structure. I think there is a far bigger problem with gain structure in the tracking chain because of a far more fundamental misunderstanding of the differences between analog and digital meter scales and the stages of gain control through the A/D tracking chain. Get that stuff wrong, as most rookies do, and intra-sample clipping ITB, while not something to ignore, is going to be the very least of your problems IMHO.

G.
 
Because the audio industry is currently stuck with non-intelligent level restrictions, such as counting consecutive samples at full scale , mastering engineers should start using oversampled meters and limiters , or at least normalize against -2 or -3 dBFS rather than 0 dBFS.
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http://www.tcelectronic.com/media/nielsen_lund_2003_overload.pdf




The method used for computing the peak value inside the system, is however not paticularly accurate .DAW and digital mixers typically take the amplitude of the samples and use these as the basis for the peak meters. The problem with this approach is easily identified: the samples themselves do not represent the peak value of the waveform. ---------------------------------------------------------------------------They save the reconstruction process for the digital to analog converters and show the user inaccurate information instead.
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http://www.cadenzarecording.com/papers/Digitaldistortion.pdf


Anybody know where you get an oversampled meter??? :confused: I want one to show me what the RECONSTRUCTED peaks are!!!!!!!
and I want it to be CHEAP! ( dreamer , ya know you are a dreamer) :p


OR better yet maybe I should just listen the guys who know and not track hot and try to " use every dam bit" ! :p

-3 ?
-6 is better! :)

:D
:D :D
:D :D :D
 
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SouthSIDE Glen said:
- the key to understanding all of that and the idea of gain structre overall, is to understand what the translation value between the analog VU signal and the digital dBFS reading is in your signal chain. That requires knowing the calibration of the VU meters on the analog side and the calibration level of the A/D converters in your chain, using the dBu measurement scale as the rosetta stone.

G.
Click to expand...


What we need is a graphic , with everything
aligned horizontially!!

Are you done yet??? :p :p :p

as to the blast above, what's a rosetta stone??
(just kidding, great analogy!!!) :) :) :)

:D
:D :D
:D :D :D
 
zed32 said:
i usually mix with my eyes. i turn the speakers all the way down, then adjust all the faders in-the-box until all the meters are just below clip, then i slap a limiter on the master track and crank the threshold down until the master meter doesn't move at all, it's just pegged at -.01...after this step, it's best to send your mix to a professional mastering house for the final touches.

also i EQ all my tracks visually, with a 10 band EQ plugin (still leaving the speakers off). i use the same EQ curve that everybody with an equalizer uses on thier home stereo, with the highs and lows boosted and the mids cut in kind of a U shape. then i put a compressor on behind the EQ and turn down the threshold until the "gain reduction" light is constantly on.

i find that mixing with your eyes is the best way. YMMV.
Click to expand...

Hey, that worked awesome Zed...Look at what I have. Sounds awesome don't it.... :p
 

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Dogman said:
Hey, that worked awesome Zed...Look at what I have. Sounds awesome don't it.... :p
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Looks gorgeous and smells even greater. inavitive use of dynamics there Dogman. Something I strive upon. :P

Eck
 
ecktronic said:
Looks gorgeous and smells even greater. inavitive use of dynamics there Dogman. Something I strive upon. :P

Eck
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The funny thing is, it didn't sound near as bad as it looks....and it's loud allright.... :D
 
flatfinger said:
Are you done yet???
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SonicAlbert said:
I'm still awaiting your interactive metering chart, Southside. I hope you are still working on it.
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Patience, children. Christmas is coming soon. It's a big job done pro bono on spare time. Paying customers get their stuff faster ;) But it's about halfway there right now.

Besides, Al, there's nothing in there that you don't already know, I'm sure. :)

G.
 
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