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#121
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Lord Hasenpfeffer wrote:
Jonas Eckerman wrote: When you say "at -10dBFS" do you mean when you set Normalize to -10dbFS or do you mean that you used another application to analyse the file and that other application said it had a -10dBFS RMS? I set Normalize to -10dBFS... like this: "normalize -ba -10dBFS *.wav" I still say you guys are fooling yourselves with this "-10dBFS RMS" terminology. The terms RMS and dBFS contradict each other. The measurement will be either RMS or dBFS. Popular applications like SoundForge enable you to normalize to either dbFS or RMS, not both. If the setting causes the waveform to exceed 0 dBFS, something has to happen to the peaks that makes them resemble something other than the original waveform. If you use the RMS method,the program asks you what you want to to if the normalize exceeds 0 dBFS - compress or clip. Sure, "-10dBFS" might be the argument you pass in your command line application, but I can't see that you really know how or where that measurement is being made. It appears to me that that setting indicates where the compression kicks in. Artie The -b engages "batch mode" (as opposed to "mix mode"). The -a indicates "amplitude" which is followed by my spec. While conducting my little WAV-MP3-WAV noise floor tests last night I used: "normalize -g -90dB test.wav" to attenuate the "gain" (hence the "g" in my command line) by 90dB - after which I could *still*, though just barely, make out some skeletal semblance of the original track after amplifying to -0.5dBFS within Audacity. Using negative values with Audacity's "amplify" feature, however, produced crap with anything beyond -40dB. What can account for the huge difference between the way Audacity and Normalize reduce loudness in a file by such different amounts, however, I haven't the faintest clue (but that's another story). Thing is that by setting Normalize to -10dBFS your actually *not* normalizing the *file* to -10dBFS RMS if I understand the documentation correctly. You are "normalizing" the file in such a way as to make the *loud* *parts* of the file -10dBFS RMS. That's quite a big difference. No, I have never found reason to believe that the entire file wasn't being affected uniformly from beginning to end. If that's what it's doing, I'm completely unaware of it. Need some more screenshots? That MFSL "Dark Side..." screenshot is a perfect, albeit low-res, before/after comparison of what Normalize "in batch mode" does to a WAV. I pulled in all 10 tracks from "Dark Side" for that screenshot after "batch normalizing" them. It was *not* Normalized as a single file as the image seems to suggest. I must concede that as I didn't really understand Normalize's documentation I might well be mistaken in this. They at least leads me to believe that something like that is what the author intends. I still have yet to read the online documentation at the URL you provided. Too much stuff to do I have. ![]() Also: When you use Normalize for batch normalizing the files from a CD, you're certainly not normalizing all the files to -10dBFS RMS. The "man page" for Normalize, seems to indicate that I am. Shall I post that complete text for you here? Your own answer to my question seems to be a rather long "yes". You found that you liked the result you got when setting the Normalize application to -10dBFS, wich as I understood the docs means that you did not normalize the files to -10dBFS RMS. Please correct me if I'm wrong. I believe you are incorrect. However, I'm still new to the terms so I still can't be sure that we're speaking the same language in every way. I've only opted to use the abbreviation for "Root Mean Square" because Geoff seemed to prefer it since he knows all about this stuff and I do not. I don't wanna look stoopider than I iz. ![]() Myke |
#122
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![]() "Artie Turner" wrote in message news:VXmPa.46 I still say you guys are fooling yourselves with this "-10dBFS RMS" terminology. The terms RMS and dBFS contradict each other. The measurement will be either RMS or dBFS. Popular applications like SoundForge enable you to normalize to either dbFS or RMS, not both. If the setting causes the waveform to exceed 0 dBFS, Oh yes it can - maybe ! Although it is not absolutely clear in the 'Normalize' application Help, it appears to normalise to a specified RMS ( a la SForge, etc) power, while adding compression to prevent going over FS. However, the programmer also says in the Help something to the effect that he knows F-All about audio engineering, so who knows. Hardly inspiring.... Yes, the term "-10dBFS RMS" is an invalid and redundant expression. Of course it is -10dB RMS *in relation to 0dBFS*, because as dB is a relative scale, and FS is the only thing it can be relative to in the digital domain ! So "-10dB RMS" itself is an adequate explanation. geoff |
#123
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![]() "Lord Hasenpfeffer" wrote in message ... Artie Turner wrote: I still say you guys are fooling yourselves with this "-10dBFS RMS" terminology. The terms RMS and dBFS contradict each other. The measurement will be either RMS or dBFS. I believe the job of Normalize is to adjust a recording's loudness by whatever dB factor is necessary to force the Maximum RMS of the recording to become either -12dBFS by default or whatever other value is specified by the user. Clipping or limiting is applied as needed in order to carry out the particular task at hand. You got it, if the Help/manual is accurate. A .WAV file with a Maximum(?) RMS value that is already in excess of either the default or user-specified value will be made quieter, not louder, in order to complete it's job. In that case, no limiting or clipping comes into play. It would be most unusual to find music with an RMS level over -10dB ..... geoff |
#124
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Geoff Wood wrote:
It would be most unusual to find music with an RMS level over -10dB ..... I agree, if you're talking the so-called "Average RMS" level. But whatever it is that Normalize refers to as "level" is almost always in the -10dBFS to -6dBFS range on typical, recent, 24-bit digitally remastered CDs. Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
#125
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![]() "Lord Hasenpfeffer" wrote in message ... Geoff Wood wrote: It would be most unusual to find music with an RMS level over -10dB ..... I agree, if you're talking the so-called "Average RMS" level. But whatever it is that Normalize refers to as "level" is almost always in the -10dBFS to -6dBFS range on typical, recent, 24-bit digitally remastered CDs. I thought we'd been there over a week ago. It is clearly RMS level of the scanned track, averaged over the whole track. That it is not labelled as such should be telling us something. What that figure is, is purely related to the dynamic range or lack thereof, and has nothing to do the 24 bits, or digital mastering/re-mastering.. Higher levels general indicate very compressed music, which can be either through incompetence or desired special effect, or both. Suggest this week you persue the FAQs already indicated, instead of in reference to dB and how they work, with regard to what mastering and remastering is. geoff geoff geoff |
#126
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Geoff Wood wrote:
I thought we'd been there over a week ago. It is clearly RMS level of the scanned track, averaged over the whole track. That it is not labelled as such should be telling us something. What that figure is, is purely related to the dynamic range or lack thereof, and has nothing to do the 24 bits, or digital mastering/re-mastering.. Higher levels general indicate very compressed music, which can be either through incompetence or desired special effect, or both. Suggest this week you persue the FAQs already indicated, instead of in reference to dB and how they work, with regard to what mastering and remastering is. Good grief, Geoff. By merely mentioning 24-bit digital remastering in my post you somehow infer that I believe in hard connections between the remastering process and an RMS level. No wonder we've never been able to communicate effectively. I have ripped and encoded a *lot* of CDs in the past 2+ years and have found that almost consistently my 24-bit digitally remastered discs have "Normalize levels" of at least -10dBFS - often higher than that by 1 or 2 dBs. Because of this I usually do not touch (with Normalize) my digitally remastered discs because "the experts in the industry" have already mastered them at or above the loudness level I personally prefer. In no way have I implied any connection with "Average RMS", or "Maximum RMS" levels and 24-bit remastering in and of themselves. I've merely noticed that newer 24-bit digitally remastered discs are almost always "appropriately loud" as I like for them to be. Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
#127
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Jonas Eckerman wrote:
Please, if I'm completely wrong here, explain how. The terms RMS and dBFS contradict each other. How? Maybe I hould have said that using the terms RMS and dBFS together is confusing. dBFS implies a peak reading to me. RMS implies an average. I'm sure there are others here who could explain this better than I - if they hadn't lost interest a few hundred posts back - but the short answer is there are peak meters and RMS meters, and you need to know what kind of meter you are using when you declare something is "x dBFS" The worst case scenario from not knowing which meter you have is that your measurement will be off by ~ 3dB. The measurement will be either RMS or dBFS. RMS is a calculation while dB is a unit. Both RMS and dBFS are based on calculations. Here's Bob Katz' definition of dBFS: "dBFS: The meters on DAT machines all read in dBFS, "decibels below full scale". Full scale is the highest signal which can be recorded. Positive going signals with a value of 32767 or negative with a value of -32768 at 16 bit are at the maximum. Levels below those are translated to decibels, with 0 dBFS being full scale. For example, -10 dBFS is a level 10 dB below full scale." Bob's definition appears to be slightly different from the AES-17 definition, but for the purposes of this discussion about "normalization" it works just fine: a value of -x dBFS will have a specific numeric value within the ranges of +- 32768 When you measure something you should specify both how you measure it and in what unit you present the values. Popular applications like SoundForge enable you to normalize to either dbFS or RMS, not both. You can't normalize to a unit, you must have some kind of basis for the normalization. Yes, you can. If you have a signal with -10 dBFS peaks, you can normalize or boost that signal 10 dB before it exceeds the +- 32768 "bucket" and the peaks are distorted. (low level artifacts are another matter altogether) A typical normalization normalizes based on the peaks. The digital peak values are typically presented in dBFS. My guess is that when you tell SoudForge to normalize to dBFS you are actually telling it to normalize to a peak value specified in the unit dBFS. Hmm, exactly. Where was the confusion? I suspect that "RMS normalization" as employed by the UNIX command line utility you're using is basically a form of boosting with peak limiting ala the LI Ultramaximizer. Artie Regards /Jonas |
#128
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![]() Maybe I hould have said that using the terms RMS and dBFS together is confusing. dBFS implies a peak reading to me. RMS implies an average. You need a unit in both those cases. Consider a completely different case: You have ten ropes of different length. You measure the lengths of all the ropes in inches. You then calculate the average length of all the ropes. Both the length of the individual ropes and the average length of the ropes will be in inches. (Of course, RMS isn't that kind of average.) Both RMS and dBFS are based on calculations. Here's Bob Katz' definition of dBFS: That definition is not a calculation. It is the definition of what the unit dBFS signifies. dBFS signifies how far below the loudest digital signal (zero) you are. RMS oth is a calculation done on a measurement, and when specifying an RMS value you are not automatically specifying a unit. To be able to present a usable RMS value, you must also either specify a unit, or use a unit that is implied by convention or necessity. In CoolEdit I have the choice of presenting RMS values based on two different reference points, and both those could be called dBFS. One is based on the RMS of a sine wave, the other a square wave. Both variants presents the RMS values as to how far below the loudest digital signal you are. A value presented without a specied or an implied unit of measurement is completely useless. answer is there are peak meters and RMS meters, and you need to know what kind of meter you are using when you declare something is "x dBFS" Of course I nead to know if the meter shows peaks or RMS values. Your own answer implies that dbFS is not only used for peak measurments. if dBFS automatically implies peak measurements, then we would allways know that "x dBFS" means a peak meter. You can't normalize to a unit, you must have some kind of basis for the normalization. Yes, you can. If you have a signal with -10 dBFS peaks, you can normalize or boost that signal 10 dB You still can't normalize to a unit. You need to normalize to a value. You can't normalize to dBFS, as that's just a unit. Of course you can normalize to 0 dbFS, -2 dbFS and other values. But then you're normalizing to specific values, not to a unit. In your example above, you are normalizing to 0 dbFS. I suspect that "RMS normalization" as employed by the UNIX command line utility you're using is basically a form of boosting with peak limiting ala the LI Ultramaximizer. Hey. I'm not using that strange utility. I've just tried to understand what on earth it does. :-) It isn't really like the L1 at all. It does calculate a whole bunch of RMS values (not an average RMS though), and does a normalization based on the loudest RMS values it found in the file or set of files. It doesn't base the normalization on the maximum RMS though, it does some more stuff so it will probably normalize on a value a bit below the maximum RMS in most cases. It does do peak limiting in order to allow digital clipping when necessary. Not that depending on the file, it might raise or lower the amplitude of the file. /Jonas |
#129
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![]() "Jonas Eckerman" wrote in message Your own answer implies that dbFS is not only used for peak measurments. if dBFS automatically implies peak measurements, then we would allways know that "x dBFS" means a peak meter. My answer implies that 0dBFS is the *only* fixed reference in the digital domain. Other dB measurements are either purely relative (dB per se) , or relate to physical analogue voltage or power levels (dBU, dBM, dBV, etc). geoff |
#130
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Jonas Eckerman wrote:
Of course you can normalize to 0 dbFS, -2 dbFS and other values. But then you're normalizing to specific values, not to a unit. In your example above, you are normalizing to 0 dbFS. Is English your primary language? Of course there has to be a value associated with the unit of measurement. I didn't think I'd have to explain that. I suspect that "RMS normalization" as employed by the UNIX command line utility you're using is basically a form of boosting with peak limiting ala the LI Ultramaximizer. Hey. I'm not using that strange utility. I've just tried to understand what on earth it does. :-) This whole thread was ostensibly about trying to understand what that utility does! I have a problem understanding what's expressed by "-10 dBFS RMS" For me, as long as you're in the digital realm, the RMS part of that expression seems redundant. It doesn't base the normalization on the maximum RMS though, it does some more stuff so it will probably normalize on a value a bit below the maximum RMS in most cases. It does some "stuff" and it "probably" does some other "stuff" in "most" cases? It does do peak limiting in order to allow digital clipping when necessary. Not that depending on the file, it might raise or lower the amplitude of the file. So it's kinda like AGC on that CB radio in your granpa's closet? Thread over. /Jonas |
#132
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Ah, here I agree with you. Normalization via RMS utilizes a totally
different method which measures an electrical (or digital equivalent) output and proceeds to bring things up to that level. Hence, RMS normalization brings things up to a perceived LOUDNESS and the algorithm doesn't care whether it's meant to be that way or not. Peak normalization picks a point that is the highest on the scale and then brings everything up in the exact same percentages necessary to maintain that peak level across the board even as that PEAK reaches 0 dBFS or any percentage thereof. If one brings a 3 dBFS peak up to -.1 dBFS than peak normalization will bring everything else up exactly the percentage necessary to maintain that ratio across the piece of music. This action may or may not bring the overall perception of loudness up. Now that I rethunk that, it's obvious that RMS normalization would inadvertantly change the overall values and constants represented in the music, while peak normalization would have the values change while the constants remain the same. I think I said it backwards in the last post. However, this only happens under the normalization algorithm. RMS can be lowered without adversely affecting the constants while the values do, indeed change. It's when one approaches the maximum RMS values that the constants are no longer constant in relation to the originals. Peak RMS normalization would make everything constantly as loud as everything else. Peak normalization on the dBFS SCALE would bring things up a certain percentage and no further. Damn, I hate when that happens. -- Roger W. Norman SirMusic Studio 301-585-4681 "Jonas Eckerman" wrote in message . 1... I believe the job of Normalize is to adjust a recording's loudness by whatever dB factor is necessary to force the Maximum RMS No. The docs are clear on this at least. Normalize does not base it's operation on the Maximum RMS. It seems to calculate the maximum RMS, but it uses something it gets from smoothing a curve of RMS-values it has calculated in the file (and here's where the docs get unclear again). /Jonas |
#133
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Roger W. Norman wrote:
I think you mean that dBFS implies a SCALE, not a peak reading Artie. No, if you're using a peak meter, like on any DAT machine, -x dBFS indicates a particular value re; the definition from the digido site. If full scale, or 0 dBFS is a digital value of +32767, then a reading 10 dB below that would a have a corresponding lower value. If you have a .wav file with a the highest peak, positive or negative, at -10 dBFS, you can normalize (increase the volume of the .wav in a linear fashion) up 10 dB without clipping. Any process, regardless of what name it goes by, that tries to increase the volume of that -10 dBFS peak more than 10 dB will cause that peak to be clipped. The SENSIBLE thing to do, should he want to make mp3s from a product with REDUCED overall volume, is to simply load in the song, turn down the output volume until he feels it's where the mp3 encoding process would do the best job, and process it. I don't think he wanted REDUCED overall volume - nobody does. He wanted louder files for tin-eared web junkies. He's basically trying to put 2 gallons in a one gallon bucket. As far as the conversation between you and Jonas, remember, it's starting from a faulty premise from Myke in the first place. One cannot explain anything adequately when the premise for the explanation is wrong. dBFS is a SCALE. Depending on the number of bits in the sample rate - dBFS indicates a precise value per Bob Katz. "dBFS: The meters on DAT machines all read in dBFS, "decibels below full scale". Full scale is the highest signal which can be recorded. Positive going signals with a value of 32767 or negative with a value of -32768 at 16 bit are at the maximum. Levels below those are translated to decibels, with 0 dBFS being full scale. For example, -10 dBFS is a level 10 dB below full scale." RMS is an average POWER level. Sure. It may sound good to Myke, but it's not the right way to do it at all. I don't think he cares. He's looking for the maximum sonic impact regardless of the changes that might occur. |
#134
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![]() Artie Turner wrote: RMS is an average POWER level. No. MS is power. RMS is in the same units as what's sampled; volts, pascals, sample values, whatever. You need to square the RMS value to get power equivalents just as you would need to square the voltage across a resistor to get power. RMS is the constant (DC) level that would need to exist to generate the same energy (into the same physical resistance) as some section of a time varying signal but it is not power per se. It makes sense to talk of the dBFS RMS level as long as you define a reference related to FS. The one that makes common sense is the RMS level of a sin wave with a peak value of 0 dBFS. Then dBFS RMS values would be defined as 20 times log10 of the ratio of the RMS value of the signal to the RMS value of that sin wave (which is just .707 if FS is 1.) Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#135
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Jonas Eckerman wrote:
I believe the job of Normalize is to adjust a recording's loudness by whatever dB factor is necessary to force the Maximum RMS No. The docs are clear on this at least. Normalize does not base it's operation on the Maximum RMS. It seems to calculate the maximum RMS, but it uses something it gets from smoothing a curve of RMS-values it has calculated in the file (and here's where the docs get unclear again). Right. At any rate, it's close to Maximum RMS; definitely much closer to that than Average RMS, I'd say. Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
#136
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Artie Turner wrote:
This whole thread was ostensibly about trying to understand what that utility does! No, it's specifically about whether or not boosting the amplitude of a source WAV file enables one to preserve more of the original frequencies in the digital recording after its been processed with a lossy compression algorithm that employs an amplitude-oriented psychoacoustic filter. The fact that it has shifted to a discussion of what Normalize does is technically off-topic but still related and often interesting nevertheless. Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
#137
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Roger W. Norman wrote:
It may sound good to Myke, but it's not the right way to do it at all. I use non-standard methods for designing websites too. The work wonderfully. Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
#138
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Artie Turner wrote:
The SENSIBLE thing to do, should he want to make mp3s from a product with REDUCED overall volume, is to simply load in the song, turn down the output volume until he feels it's where the mp3 encoding process would do the best job, and process it. But wouldn't turning the volume down cause more frequencies to be killed off by the ATH-filter? I don't think he wanted REDUCED overall volume - nobody does. He wanted louder files for tin-eared web junkies. This is not entirely true. I'm doing *several* things at the same time with this software and my WAVs, not just one - and not all of them are web-related. But that's beside the point. It may sound good to Myke, but it's not the right way to do it at all. I don't think he cares. He's looking for the maximum sonic impact regardless of the changes that might occur. I do care. I'm just not so anal about all of this from a professional-CD-mastering POV - because I'm not in the business of mastering professional CDs. If I was, I'd certainly take a significantly different approach. "Maximum sonic impact without doing obvious harm" is probably more like it. There have been times when it was obvious that I'd Normalized a recording too much. When this happens I simply re-Normalize to a more conservative level (i.e. the app's default value of -12dBFS is usually quite nice). Myke -- -================================- Windows...It's rebootylicious!!! -================================- |
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