Average RMS power in Amplitude Statistics

I am wondering on how to calcuate the average RMS power using the window width? How does the window get the sample information from the sound file?
Thanks
Leo

>...but I could see that from a pure theory point of view it might be possible to "slide the window" over one sample at a time. That is how my professor (many years ago)in digital signal processing would have suggested it be done.
I don't think he would have! Let's take the standard sample window size of 50ms. At 44.1k that contains 2,205 samples. So there would be absolutely no point in sliding a dirty great window like that over a single sample at all, would there?
Disregarding that bit about dynamic range (which may well be BS), the basic idea is that you are calculating the square root of the mean value of the signal squared - that's what RMS stands for. Because you've squared the mean value of the wave, it's always going to be a positive value. And note that this is the mean value of a repetition of the
wave, not a sample. And we are talking about the
arithmetic average value of all of the waves in the sample window, so all of the positive and negative excursions are taken account of.
'Series' in this context means that the selected part of the wave being analysed is treated as a sequence of windows of whatever size you've chosen - sliding doesn't come into this at all. Statistically, Audition can give percentages of windows with low and high values, and calculate the average RMS value based on this.
The reason that I think the dynamic range bit might be BS, or at best completely back to front is that you'd need to make sure that you'd used short samples to catch the quietest and loudest parts to have them treated as such, rather than lumped in with a larger sum with either a higher or lower average value, which you'd get with longer samples. But I have to say that when I tested this with a range of different window sizes, it really didn't make a lot of difference.

Similar Messages

Average versus Total RMS power

HI,
I have version 2.0 of Audition and am trying to figure out how Audition is calculating the Average versus Total RMS power values shown in the amplitude statistics window. The Help section describes the two values as
Average RMS Power Shows the average amplitude. This value reflects perceived loudness.
Total RMS Power Represents the total power of the entire selection.
But I'm looking for the details regarding how they are coming up with these numbers.
Any thoughts?
Thanks,
Ben

BWYH wrote:
I'll generate a few test files and see if I can figure it out myself.
We've all been there and tried that, and the chances of coming up with an absolutely correct answer are not good at all - to the point of vanishing. The problem is that when the average value is computed, it's done something along the lines that Leq is calculated - but not quite. And even with absolutely fixed values in files, you will still find that variations in time make a significant difference to the results.
If you really want to know why you won't be able to do this just from a few files, it's because you will be trying to recreate the values in formulae like the ones here by working back from given results. I have an MSc. in acoustics, and I don't even fancy trying, quite frankly!

Need work-around for 'amplitude statistics' bug

Does anyone know how to get adobe audition 3 to report the correct "amplitude statistics" for a selected audio clip?
It is obviously broken now (it worked fine in Cool edit Pro days), to show this simply do this:
create a new file
generate a one second sine wave at 1004 Hz,-6 dB amplitude, no modulation
check the "amplitude statistics" window
The results (for all or any part of the constant sine wave) should read -6 dB for all the catagories (Max, Min, Average, Total). In Audition 3 they typically read other (random?) numbers, however if you select a section of the sine wave near the middle with the selection length the same size as the amplitude statistics window it is sometimes possible to get the correct readings. Just the fact the reading change for various selections in a constant level sine wave shows there is a bug.
Fine.... but does anyone know if there is some way to get a correct reading out of Audition 3 ? Could I turn off some other features, or select the audio section to report the RMS level for in a very particular way?
Thank You.

Here is a really simple example of how adobe Audition 3 is reporting
incorrect values for the amplitude statistics of a selection that
only includes a CONSTANT AMPLITUDE SINE WAVE. Note that for a selection that has only includes a single constant RMS level signal, the reported RMS levels for:
MINIMUM RMS LEVEL
MAXIMUM RMS LEVEL
AVERAGE RMS LEVEL
TOTAL RMS LEVEL
should all be exactly the same (by defination ! ! !)
How to create an example of the incorrect reporting:
1) open Audition 3.0
2) create a new file (for example use mono 16 kHz, 16 bit depth)
3) generate 10 seconds of silence
4) make sure "Preferences-Data-smoothing" are both not checked
5) position cursor at 5 seconds (in middle of silence)
6) generate a sine wave at -6 dB amplitude, 1 second long
7) leave freshly generated sine wave selected
8) open amplitude statistics window
9) select "0 dB = FS sine wave" and default 50ms window width
10)note incorrect statistics reported:
Minimum RMS power -inf dB
Maximum RMS power -6 dB
Average RMS power -8.33 dB
Total RMS power -7.28 dB
At no point in the selection does a window have 50ms of -inf samples
The maximum power is correct
The average power is incorrect, it should also be -6 dB (constant sine wave!)
The total power should also read -6 dB, for a constant -6 dB sine wave
11) now close the amplitude statistics window and select the last 200ms of the
sine wave (from second 5.8 to 6.0)
12) open amplitude statistics windows again (still using 50 ms windows)
13) note the (really) incorrect statistics displayed:
Minimum RMS power -inf dB
Maximum RMS power -inf dB
Average RMS power -inf dB
Total RMS power -inf dB
I assert the Adobe Audition 3 amplitude statistics numbers are obviously wrong. It looks like the calculation is being done over
an incorrect section of some data buffer.

How is TOTAL RMS different than AVERAGE RMS

I create spoken-word recordings. One company that I work with specifys that the recording should be at a level that measures between -23 RMS and -18RMS. It appears that audio editing programs label their RMS readings in various ways. I had been using Average RMS but I think maybe this company is using a standard that comes closer to what ADOBE calls TOTAL RMS. What attributes cause Audition to give one value to AVERAGE RMS and another value as AVERAGE RMS?

Total RMS used to be what happens if you add together all of the signals in your measuring time window (in Audition normally 50ms), and perform a RMS calculation on them, and that was a pretty standard way of measuring it. Average RMS in Audition is a little different, though. Reading through the somewhat cryptic help files about this reveals that to all intents and purposes, the RMS measurements will vary at different levels, because some attention is being paid to either Noise Criteria or Noise Rating curves. The lower the level gets with these, the more they favour lower frequencies over higher ones; in other words the figures reflect human annoyance factors rather than a specifically defined measurement criterion. And no, we can't tell you exactly how this is going to work, because the actual curves and weighting figures have never been made public, and it would take me several days to second-guess it from comparative readings. I simply don't have time...
It's been like this for ever. The original design of this was done by David Johnston, the program's original creator when it was Cool Edit, and I belive he's no longer associated even indirectly with Audition these days. Whether information about this is actually documented anywhere at all, I don't know. Questions about it come up periodically, and we can never answer them satisfactorily.
The original Cool Edit manual was just as useless about this. The exact words it uses to describe the Average RMS measurement are "Average RMS Power represents the average power of the entire selection. This is a good measure of the overall loudness of the waveform selection." And it's these words I've bolded that make the difference.
What happens with Total RMS measurements now seems to be a little different, and you end up with a figure much closer to a LUFS reading (you get this acccurately at the bottom of the statistics panel in CC). I know (because this is relatively recent) that the way the LUFS figure is calculated is according to the BS1770-2 standard - and that takes the whole program dynamics into account. What appears to happen with Total RMS in Audition is that it appears that an average of all of the windowed measurements, and that this in general turns out to be pretty close to the LUFS value as a rule.
Now, judging by the numbers they've quoted, the chances are that the company you are working for is using the recent standard for what you're doing - so if you are using CC, then it's pretty easy - select the whole waveform and quote them the value shown at the bottom of the screen. If you aren't using CC then there are several free LUFS meters available as VST plugins.
My personal view on this new standard, FWIW, is that it's a complete waste of time. It certainly doesn't achieve what it sets out to, or failing that all the broadcasters that use it have no idea what to do with it. And that very much includes the BBC, I'm afraid. The standard is supposed to keep overall programme dynamics within a certain loudness range, and save viewers/listeners having to adjust volume levels between programmes. And, it fails at that pretty comprehensively. Quite frankly, when it comes to broadcast dynamics standards, they'd have been better off forcing everybody to use the same settings on an Orban Optimod; that would almost certainly have worked better!

Averaged RMS vs. averaged FFT peak

I have an application whereby I record several vibration signals of a spinning apparatus. The recording process is automated for a production stand, and two numbers are displayed for each channel - one is the averaged RMS value of the integrated waveform; the other is the discrete peak amplitude at the run speed frequency. Normally, the RMS value is larger than the discrete peak, as I expect. Every once in a while, though, the discrete peak is higher. Should this be possible?
Note that the waveforms are not recorded as part of the production process, and the observed results are not easily reproduced.

Hi AEI_JR,
Could you elaborate on any specific LabVIEW functions that you are using to get your RMS and FFT?
Also, how are you measuring this signal, what kind of numerical values
are you expecting, and how often are you seeing these suspected
outliers? This will provide a better understanding of what exactly is
expected behavior for your setup.
Developer Zone Tutorial: The Fundamentals of FFT-Based Signal Analysis and Measurement in LabVIEW a...
Thanks!

ITU.R BS.1770-3 Loudness not implemented in Adobe Audition CC 2014 Amplitude Statistics

The amplitude statistics feature in Adobe Audition CC 2014 is a great tool to quickly analyze the long-term loudness; however, it is currently using an old standard (BS.1770-2) that has been replaced by the new BS.1770-3 for about a year or so now. Is there any reason why Adobe has not updated the amplitude statistic tool to BS.1770-3? I noticed that in the Adobe Audition training videos the TC Electronic Radar is mentioned, which does have the current LKFS reading standard but it is in real-time. While useful, it slows you down since you have to sit through the entire program to get the LKFS reading, unlike the amplitude statistics that scans the file quickly. Please advise.

The Loudness Radar meter is a passive meter, and doesn't affect the audio signal in any way.
When the Match Volume and Amplitude Statistics support for ITU-based loudness was implemented, 1770-2 was the most recent specification. Since then, 1770-3 has been released which makes some minor modifications. I've recently chatted about this with our engineering team, and form my understanding the primary difference in -3 is a simplification of the definition of True Peak Level. All loudness measurements and adjustments continue to be the same as the -2 spec. The update is on in our feature backlog, however, and will be prioritized with other feature work.

Problem with Amplitude Statistics

I'm a relatively new Adobe Audition user and am trying to use it to identify peaks in my recordings of gunshots, but am having problems. I generally have 3-4 gunshots recorded in 1 file and need to find the peak amplitude of each one. I was under the impression I could select each gunshot in turn and use Window -> Amplitude Statistics to find the peak amplitude for the selected recording, but it keeps giving me amplitudes for what are quite clearly (by visual inspection) not the peaks, or the peak of the next gunshot (which hasn't been selected). Can anyone help me with this problem or has anyone experienced anything similar?
Many thanks.
Lisa

Well it works fine here, exactly the way you are using it, but there are two things:
Firstly, when you are zoomed right out, you don't necessarily see all of the peaks - they can easily get lost. Sometimes you have to zoom in quite a long way to see the true ones.
Secondly, if you aren't running it, then download and install the 3.0.1 patch for Audition - this has a number of bugfixes in it, including one for the Amplitude statistics.

What is the difference between Total RMS and Average RMS?

There is a difference I am seeing between Average RMS in Audition 1.5 & Audition CS6. I inserted the same track into each version and selected the same segment and below are my results. Thanks!

Thanks for your response. Both versions have square wave setting, 50ms window and account for dc box checked. Any other thoughts? Kind of a mystery.

How is actual bit depth measured

I am analyzing some recordings I made in 24-bit format in Audacity. Audacity can record true 24-bit integer files which Audition 3.0.1 recognizes as such.
After checking a couple of the files in Audition 3.0.1, I found that the meaning of "Actual bit depth" in the amplitude statistics is not entirely clear. It does seem to be based on the maximum peak in the file, but the bit estimate does not seem too clear.
For example, in one of the files if I select any portion that includes the highest peak and get amplitude statistics, the actual bit depth reported is 24. Example of a short selection that includes the peak:
Mono
Min Sample Value:    -22003
Max Sample Value:    26329
Peak Amplitude:    -1.9 dB
Possibly Clipped:    0
DC Offset:    -.003
Minimum RMS Power:    -44.45 dB
Maximum RMS Power:    -17.58 dB
Average RMS Power:    -30.18 dB
Total RMS Power:    -25.98 dB
Actual Bit Depth:    24 Bits
Using RMS Window of 50 ms
However, as far as I can tell, any selection in the same file that does not inlude the highest peak (but may include nearby close peaks) results in actual bit depth of 16:
Mono
Min Sample Value:    -20082
Max Sample Value:    22172
Peak Amplitude:    -3.39 dB
Possibly Clipped:    0
DC Offset:    -.001
Minimum RMS Power:    -54.14 dB
Maximum RMS Power:    -19.96 dB
Average RMS Power:    -36.26 dB
Total RMS Power:    -32.95 dB
Actual Bit Depth:    16 Bits
Using RMS Window of 50 ms
So it is unclear what level of peak amplitude distinguishes between 24- and 16-bit actual depth. If the bit-depth analysis is based on most-significant bits being zero, I would think that the trigger for identifying 16-bit actual depth in a 24-bit file would be to find that the 8 most-significant bits of the 24-bit samples are zero for all samples in the selection. So for a 24-bit integer file to have actual bit depth of 16 bits for a slection, the greatest peak would be less than -48 dBFS. But in the example above, the distinction seems to be having a peak amplitidue around -3.4 dB versus -1.9 dB.

>what actual difference does it make to anything?
Hard to say what difference it makes to anything without knowing what "actual bit depth" actually measures. It could be important, or could be useless. In the past I have not paid much attention to it because it is poorly described. It recently came to my attention because the files from a recent recording in 24-bit integer format were all reported as 16-bit "actual" bit depth. This is in contrast to some previous recordings made in the same way which were identified as 24-bit "actual". This implies there might be something different in the data formatting, the communication between the software and driver, between the driver and card, or something else.
It is a bit surprising that no one got Synt. to explain it properly.
>Oh, and the other thing about 24-bit int files is that they can lead you into a very false sense of security. If you decided, for instance, to reduce the amplitude of one by 48dB, then save it, and then decide to increase it again by that 48dB, you'd end up with a 24-bit file with just 16 bits of resolution - simply because it's an integer file. If you did the same thing with Audition's 32-bit floating point system, you'd lose no resolution at all.
In my workflow that produces original recordings in a 24-bit integer file format, the format is an efficient way of storing 24-bit integer data from a 24-bit card. Processing is another matter. I use the Audition preference to convert files automatically to 32-bit when opening.

Feature Suggestions for Logic Express

I think it would be a great thing to put all our user suggestions in one Topic for the powers that be @ Apple to see easily.
1. Include Wave Burner in the next update ( We small project studio Guys need to burn redbook cd's as well)
Seeing as OS X comes with iDVD
I think this is a small thing to ask for ,but would be an incredible help !
Also a some midi plug-ins would be nice
ie: Step sequencers, arpeggiator etc..

I'd like to see more options for waveform editing:
1) For example, I select portion of the waveform, and I want to see what is average RMS power, maximum RMS power, how many clipped samples, and option to place markers where there are clippings. Even Amadeus Pro ($40) has it. It would be nice if I had no need to travel to Amadeus to check my audio files...
2) Markers as thin vertical lines across the waveform. During recording I may notice some problems, and could insert markers. (Now I have markers from the insertation point to the end of the audio clip.)
When I record audio and little bit zoom in, I get splitted waveform being drawn on the screen. About 2-3 pixels blue background with the waveform, then 2-3 pixels of the empty space, then again 2-3 pixels waveform, then again 2-3 pixels empty space, etc. Can this be improved so that I see whole waveform during recording? In Sound Studio I can zoom in at 1:256 and still I can see normal waveform during recording.

Average system statistics

Hi all,
I have a package which captures system statistics into a user specified table using the usual method:
--1. Create user defined stats table to store stats
DBMS_STATS.CREATE_STAT_TABLE (ownanme => 'STAT_ADM' ,stattab=>'STAT_LOG' ,tblspace=>'STATS');
-- 2. Collect statistics under workload and store them in user stats table:
DBMS_STATS.GATHER_SYSTEM_STATS (gathering_mode => 'INTERVAL' ,interval => 120 ,stattab => 'STAT_LOG' ,statid => 'SYS_YYYMMDDHH24MISS');
When applying the system stats I would like to obtain an average of the system statistics stored in my user defined table over a time period, and use this average to set the system statistics, ideally also storing the average in the same table first so I can reuse or have a log. I'm not sure how to go about doing this since the stats table stores two values for a single capture and has some strange and missing values in some cases. Does anyone have any ideas or code which can I assist me please?
STATID T VERSION FLAGS C1 C2 C3 C4 C5 N1
N4 N5 N6 N7 N8 N9 N10 N11 N12 D1 R1
R2 CH1
THU_20090312130 S 4 0 COMPLETED 03-12-2009 13:00 03-12-2009 1 CPU_SERIO
0 4:00
444755765 879118370 313803318 850441300 10067568 9385896 0 8 4085027062
THU_20090312130 S 4 0 PARIO 41110528
0
0
Any help is greatly appreciated. Thanks.

cwong wrote:
Hi all,
I have a package which captures system statistics into a user specified table using the usual method:
--1. Create user defined stats table to store stats
DBMS_STATS.CREATE_STAT_TABLE (ownanme => 'STAT_ADM' ,stattab=>'STAT_LOG' ,tblspace=>'STATS');
-- 2. Collect statistics under workload and store them in user stats table:
DBMS_STATS.GATHER_SYSTEM_STATS (gathering_mode => 'INTERVAL' ,interval => 120 ,stattab => 'STAT_LOG' ,statid => 'SYS_YYYMMDDHH24MISS');
When applying the system stats I would like to obtain an average of the system statistics stored in my user defined table over a time period, and use this average to set the system statistics, ideally also storing the average in the same table first so I can reuse or have a log. I'm not sure how to go about doing this since the stats table stores two values for a single capture and has some strange and missing values in some cases. Does anyone have any ideas or code which can I assist me please?I'm not sure if your approach is reasonable. Do you expect to see such dramatic differences between the measurements that you want to apply some special logic to the system statistics gathered? Can you come up with an concrete example how you think that you're going to have an added value by doing so?
Anyway, if you want to manipulate system statistics you shouldn't fiddle around with the statistics table itself, but use the documented API to get and set the values:
DBMS_STATS.GET_SYSTEM_STATS/SET_SYSTEM_STATS
These can be used on user-defined statistics tables, so you should be able to get your statistics, massage them somehow and write them back using a new STATID identifier.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/

Finding average amplitude of frequency

Hey guys,
I'm new to this forum and I am looking for some help with finding the average of a frequency-amplitude graph. I tried multiple example codes I've found on here and none of them really worked for me. I attached my program to this post. The problem I am having now is that my averaged graph looks exactly like my originial graph and I don't know why... theoretically I think I'm correct because I add one everytime the loop execute itself and then it divide the graph by the number I got and therefore it's the average. The average code is near the bottom of the picture I've attached, everything else works fine in my program. Please let me know what you think!
Also, a lot of times I like to ask really obvious questions. Sorry if this is one of them! Thanks in advance for helping out and let me know if you need any addtional information!
Attachments:
HansLabView.JPG ‏151 KB

I cannot tell how you have the express VIs configured from looking at an image.
The averaging done by the spectrum express VIs keeps track internally of the number of iterations in much the same way as you are doing. Open the VIs and look for yourself.
So it appears that you have an averaged spectrum and an averaged spectrum divided by an integer. It is not clear that you have an "instantaneous" on "un-averaged" spectrum.
Lynn

RMS terminology and power comparison standards

I am doing my research in order to find the best of the best 2.1 speaker system for my PC. I already have an AUDIGY 2 SE soundcard and I would like to support it with an excellent sound output set. While comparing different speaker systems I have came up with the following two best of the best products: Creative I-Trigue L3800 (Price 99GBP) and Logitech Z-2300 (Price 91GBP). Even if these are the best of the best it seems that they have a serious difference of power between them. Here is the RMS speaker power specifications:
1.Creative I-Trigue L3800: 9 Watts RMS per channel (2 channels) 30 Watts RMS subwoofer 2.Logitech Z-2300: Total RMS power: 200 watts RMS Satellites: 80 watts RMS (40 watts x 2)
Subwoofer: 20 watts RMS Total peak power: 400 watts
My conclusion from the above data is that Logitech Speakers are 4 times more powerful from those of Creative (200 watts compared to 48 watts). Is my above conclusion correct? What else do I have to compare in order to buy the best system?

Clearly the " RMS " is the standard.
They do clarify their goofy ratings
in small print on some pages.
Those LT's you mention are great deal.
Very similar but in a revered brand - KLIPSCH -
a similar system is available for about $30. more.
That 'THX' certification is supposedly a big deal.
Big plus with the L3800 is remote controls functions
on Zen Vision M.
good luck

Waveform averaging

Hello.
I have to acquire noisy sine signal (about 30 kHz) with NI PXI-5105 60 MS/s digitizer. I tried to make a VI using LabVIEW help but got the following result:
Apparently, it is necessary to make waveform averaging but I don't know how to do such a thing.
Here shows how signal is indicated:
I found here the following example from RavensFan, but could not use it:
There is a type mismatch:
Is there somewhere a detailed description of the LabVIEW's waveform / complex waveform / … data types with examples? I so stupid and standard LabVIEW help did not help me.
Thanks in advance for your help and sorry for my poor english.

Try:
Extract Single Tone Information VI
Owning Palette: Waveform Measurements VIs
Requires: Full Development System
Takes a signal in, finds the single tone with the highest amplitude or searches a specified frequency range, and returns the single tone frequency, amplitude, and phase. The input signal can be real or complex and single-channel or multichannel. Wire data to the time signal in input to determine the polymorphic instance to use or manually select the instance.
and
Averaged DC-RMS VI
Owning Palette: Waveform Measurements VIs
Requires: Full Development System
Calculates the DC and RMS values of an input waveform or array of waveforms. This VI is similar to the Basic Averaged DC-RMS VI, but this VI gives more precise control over the individual DC and RMS calculations.
Do you really want the RMS or the amplitude of the 30kHz signal??
Have a look at the (power) spectrum of your signal .. will help you identify (and eliminate) the noise.
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

Inspire 7.1 & 5.1 Total power of all speakers in PMPO

I'm Planning to buy a creative sound speakers inspire T7900 7.1 Or T6060 5.1 So Please Can Anybody Help me because i need to know as soon as possible the total power of their speakers not in RMS but in PMPO Thanks

RMS is a more accurate power measurement when compared to PMPO. RMS stands for root mean square. First a varying quantity is squared, then the average taken, then the square root. This gives an average typical value. For instance a 100Watt RMS amplifier can produce a 100Watt sine wave into its load. PMPO on the other hand stands for peak music power and it tells the power which the amplifier can maximally supply in some conditions, usually transients lasting only milliseconds assuming the amplifier is operating at 100% efficiency which is impossible. PMPO rating gives the highest measuring value but is quite useless because there is no industry standard how PMPO power should be measured. PMPO varies between manufucturers, and is calculated by their marketing department, they just pick a number that sound cool and come up with a formula that would result in that number. Have you ever wondered how some cheap home stereos claim they can produce 2600W PMPO from an amplifier powered by a 6Volt power supply? Vendors use PMPO to hide under-powered power supplies and amplifiers. Therefore RMS is the real measurement of power. So your question of finding the PMPO power rating from the RMS value has no single answer or mathematical formula to convert the RMS value to PMPO. This is simply because each amplifier manufucturer will produce their own propretary formula for figuring out PMPO power. That is why good quality amps and speakers, from respectable manufuctures like Creative for example, are rated in RMS power. But if you still want the PMPO value then usually the PMPO value is about fi've to ten times higher than the RMS value.

Average RMS power in Amplitude Statistics

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