Industry Standards?

[fenix]

look, all I know is that the crap I listen to (pop rock, punk, metal...the same stuff on hard rock format stations) usually has average db levels of -10 to -8 on the meters. I even gave you a picture of that. If you guys are saying this isn't it, so proove to me otherwise!

 

[sonicpaint]

Search online for some more answers.

Fenix I think what has to happen is you have to prove it to yourself. I don't think anyone can really change your mind at this point. Your thoughts on this subject are going to only be changed by you doing some research on the net and finding a source that you think is credible with the answer.

I wish you all the best because that's a large part of how we all learn.

sonicpaint

 

[fenix]

Re: Search online for some more answers.

Fenix I think what has to happen is you have to prove it to yourself.
sonicpaint

fine...give me a day. I'm still gonna use the meter in wavelab though. I'll list a couple well known commercial songs.

 

[sjoko2]

look, all I know is that the crap I listen to (pop rock, punk, metal...the same stuff on hard rock format stations) usually has average db levels of -10 to -8 on the meters. I even gave you a picture of that. If you guys are saying this isn't it, so proove to me otherwise!

I presume you are talking about your radio receiver. What you'll have to understand is that that has nothing whatever to do with the levels in the broadcast studio, its simply the way your receiver deals with the transmitted signal, that's all. In order to measure a broadcast signal you'd have to be in the studio, with a meter at the end of the broadcast chain, prior to the transmitter.

 

[fenix]

I think this thread has kinda lost focus. Let's do a recap of the original intent (at least what i think the intent was) of this thread.

Hey you all!

I just wondered if anyone was familiar with industry or airwave standards for audio masters.

AIRWAVE STANDARDS FOR AUDIO MASTERS. That's the key phrase. No where did this guy mention airwave standard rms coming off a receiver. In other words he is asking when a radio station receives a single or a cd, what is the expectation of how loud it is (on the cd)? In other words, "if I send my band's demo to a radio station, generally, what should the rms be (on the cd)...i don't want it to come off the radio "sounding unmastered"

Here's my answer. Tell me I'm wrong if you have something to back it up. As said before, there are really no standards, but cds have been getting hotter and hotter over the years. Like I said before, cds that are aired, you should expect them to have an rms of around -10 +/- 2db. THIS IS AN RMS OF THE SONG ON THE CD, NOT COMING OFF THE RADIO!!! Coming off the radio, yes...songs have an rms close to 0 db--but that is no the question originally asked, sjoko2!

Here is a nice little photo of the waveform of the Blink 182 song "all the small things". I chose this song because it was aired quite frequently on mtv and every rock radio station in heavy rotation. You will notice the blue meter shows the average (rms) level. This particular section is during the chorus of the song which happens to be a bit louder than the rest of the song.

I know what's gonna be said so I'll spare yourself the typing.

"Blink 182 isn't even a real band. The meter is wrong. That's not real music"

Real music or not, it was on the radio. It was a radio single. I have plenty of more non-blink 182 radio singles I could break out for ya. Don't make me break out Audioslave or Godsmack or something like that.

 

[fenix]

here it is:

 

[Son of Mixerman]

Yup, overcompress and when it comes to radio play -- they will put some "standard broadcast" compression on top of it -- and your mix is gone to hell.

Sjoko2, that is a gross oversimplification.

Some....you mean like some nuclear weapons?
Radio broadcasters use gobs of compression, gobs of other processors..gobs and gobs of things that destroy the dynamics so that their radio station is the loudest "sounding" station in the area. One of the biggest problems is they hypercompressed and over limited material sends the error correlation into a tizzy.
Here is some help on understanding from a knowledgible resource from Glenn Meadows site.

On 5/15/01 11:38:00 PM, Bob Katz wrote:
>Bob O., you're doing a great
>service for the audio
>community. If you wish to
>reach a larger audience with
>this message, I think you may
>have to rewrite the article
>less technically. I fear this
>may only reach the
>technically-inclined, or,
>shall we say "preaching to the
>converted".
>

I think what I?ll do (based on this, plus other comments) is to rearrange the article,
putting the Garbage In? and Conclusions before the technical details. I want to retain
the technical details for the benefit of technical people in the recording industry
who have never encountered a broadcast processor in the flesh, and who make
unwarranted assumptions about how they worked based on experiences they have had with
recording studio compressors and limiters (which are different beasts altogether).

>
>>Phase rotator
>
>
>SNIP
>
>
>
>>frequency. The practical
>>effect of this non-linear
>>phase response is that
>>flattops in the original
>>signal can end up anywhere in
>>the waveform after processing.
>
>Just how long a "flattop"
>would you consider to be
>audibly significant in terms
>of screwing up the phase
>rotator? In other words, if I
>used the Waves L2 to reduce
>the level of an occasional
>short peak (say, once every 10
>seconds of only a few- say 10
>---milliseconds length) by 2-3
>dB and then gain makeup in the
>L2 to bring the gain back to 0
>dB, would this be a
>significant flattop to the
>phase rotator?
>
>Note that the Waves L2 itself
>reduces peak to average ratio
>with relatively little audible
>distortion and not exactly
>clipping, when used
>"conservatively" as described
>above.
>

The phase rotator is simply a linear filter and is not really ?screwed up? by anything
that you throw at it. The problem is that it completely changes the shape of waveforms
applied to it. Therefore, a peak limited signal presented to its input is no longer
peak limited at its output, because the location of the peaks has been scrambled.
However, any audible distortion caused by the peak limiting process (which might have
been tolerated for the sake of achieving higher loudness) is retained. So you have the
worst of all possible worlds--you have retained the distortion, but none of its
?benefits.?

It?s necessary to distinguish between clipping and limiting. ?Clipping? to me is
literally that--a brute-force shaving-off of part of the waveform, which is typically
done in the studio by devices like the soft clipper circuit available in some Apogee
converters. Typically, clipping is used on drum hits and often lasts as long as 5-10ms
(with kick drum). One of the problems with severe clipping of this nature (and I?ve
seen some _very_ severe clipping on CDs) is that it shuts down other audio information
for the duration of the hit (because of the smooth flat-topping) and can therefore
sometimes sound similar to compressor or limiter pumping. This artifact is above and
beyond the problem of overt distortion caused by clipping of repetitive waveforms.

I haven?t had an opportunity to test an L2 yet, so I don?t know if it makes flat-tops
that shut down other information, as clipping does. If the L2 doesn?t do this, then
its artifacts are in a different class than those produced by soft clipping.
(Typically, fast wideband limiters produce various forms of ?spectral gain
intermodulation?--mainly modulation of midrange elements by bass. If the limiter
release time is fast enough, this can be heard as IM distortion with material like
exposed singing voice over heavy sustained bass.) In any event, I wouldn?t expect
occasional peak reduction by the L2 to have the same effect as clipping, providing
that the L2 retains midrange and HF information when it operates on peaks caused by
elements like kick drum.

>
>>material. Accordingly,
>>clipping does not cause
>>pumping, which gain reduction
>>can do, particularly when gain
>>reduction operates on
>>pre-emphasized material.
>
>You should try out an advanced
>auto-release limiter like the
>Waves L2. It may change your
>mind about limiters instead of
>clippers.

>
>>Clipping also causes minimal
>>HF loss by comparison to HF
>>limiting that uses gain
>>reduction.
>
>I'd be curious about seeing
>you try a circuit like the L2
>for this purpose, compared to
>a clipper. Perhaps you are
>right, no limiter may be as
>good as your clipper for the
>purposes of FM preemphasized
>material. But worth a try.

I?ve been designing auto-release limiters for 25 years, so I have a fairly good feel
for the tradeoffs. Ultimately, no auto-release circuit, regardless of how clever, can
compensate for spectral gain intermodulation in wideband limiters and compressors,
unless there is frequency contouring before the sidechain detector. (In this case, the
circuit can longer work correctly as a peak limiter, because its threshold will change
as a function of frequency.)

75us pre-emphasis causes _severe_ spectral gain intermodulation when strong high
frequency material (particularly above 10kHz) is present along with midrange. The
ear?s sensitivity starts to decline radically above 10kHz. When pre-emphasis
exaggerates material in this range by 10dB or more, then this HF material starts to
push down the midrange. In an FM receiver, this processed signal is then passed
through a 6dB/octave lowpass filter (-3dB at 2.1kHz), further reducing the audibility
of the high frequencies. So the ear is confused by the midrange?s being pumped by
something that sounds _much_ quieter than the midrange by the time it has passed
through the receiver de-emphasis. The midrange greatly dominates the presentation, but
its loudness is flailing wildly up and down for no apparent reason.

This problem has been well known in broadcasting since the late 1940s, when wideband
peak limiters were first put after pre-emphasis to protect FM transmitters. Cymbal
crashes in classical music would cause the sound to literally collapse. High frequency
limiting is actually a later innovation. It was introduced in the 1960s, first with
the CBS Labs Volumax 410, and, sometime later, with the BBC ?variable emphasis?
limiter. The BBC design also incorporated (analog) look-ahead limiting, but it was
located in the wideband gain reduction stage that preceded pre-emphasis.

Both of these designs used quasi-linear HF limiters with release times typically in
the order of 10ms. (By quasi-linear, I mean that their steady-state harmonic
distortion measures relatively low.) It was observed that both designs could cause
_severe_ audible HF loss with certain material. Distortion-cancelled clipping was a
response to this observed problem. In exchange for more smearing at high frequencies,
distortion-cancelled clipping greatly reduced the problem of audible loss of
brightness. The smearing turned out to be far less objectionable to most people than
the overt dulling caused by earlier HF limiter technology.

Interestingly, the Fairchild Conax (an earlier design than either the Volumax or the
BBC limiter) used a crude form of distortion-cancelled clipping and had noticeably
less audible HF loss than the systems using gain-reduction-style HF limiting. The
Conax suffered from a naïve design that didn?t preserve peak levels well. It also
should have had some sort of gain-reduction-based HF limiter before its clipper, where
the HF limiter was tuned to operate on HF overloads so severe that they otherwise
would have caused audible distortion in the clipper, reducing these overloads just
enough to prevent clipper-induce distortion.

Although I haven?t tried the L2 for limiting after 75us pre-emphasis, I did try it
with the L1, and the results, as I expected, were quite awful, with unnatural gulping
and pumping induced by the amplified HF energy. Lookahead limiting is great for ?flat?
media, but not for media with extreme pre-emphasis.

>
>For these reasons,
>>most FM broadcast processors
>>use the maximum practical
>>amount of clipping that?s
>>consistent with acceptably low
>>audible distortion.
>
>About how many "dB" of
>clipping is this?

It depends very heavily on the nature of the program material. When the clipping is
doing HF limiting, it?s not unusual to see as much as 5dB clipping depth in a
distortion-cancelled clipper.

Modern Optimods actually use a two-stage clipper. The first stage operates above 6kHz,
and difference-frequency IM distortion below 6kHz is radically attenuated. The >6kHz
distortion-cancelled clipper may do as much as 10dB clipping with program material
having aggressive high frequency content. Of course, this amount of clipping smears
the spectral details above 6kHz, and can cause artifacts like removing the tonality of
cymbals, making them sound more like filtered white noise. This is one reason why
excessive HF content is NOT a good idea in mixes designed for FM radio airplay. I
mentioned in the article that HF limiting causes HF material to get either ?dull or
distorted.? I hope the above discussion clarifies why this is true.

>
>>their signal paths. These app
>>notes emphasize that any
>>clipping in the path before
>>the processor will cause
>>subtle degradation that the
>>processor will often
>>exaggerate severely.
>
>I repeat myself: Are you
>saying: "Clipping?" or
>"Limiting?" or both, in the
>path before the broadcast
>processor. For example, if I
>use a delicate peak limiter
>which yields a program with,
>say 10 dB peak to average
>ratio, is this going to be bad
>for the broadcast processor?

There?s no easy answer here. True clipping of the source material is almost always bad
for a processor unless the clipping has a very low duty cycle and is substantially
below the threshold of audibility before being processed by the broadcast processor.
(This is a bit like the issue of ?contribution quality? in a lossy codec, where the
codec-induced noise has to be comfortably below the psychoacoustic masking threshold,
rather than being right at the threshold, as might be true for a ?transmission?
codec.)

Heavy limiting can cause a different problem, which I believe I discussed in an
earlier post. The compressors and limiters in an Optimod all use automatic,
program-adaptive release circuitry. This has been tuned to sound natural on material
having a ?normal? peak-to-average ratio. Heavy digital limiting that reduces this
ratio can interact with the time constants in the Optimod in an odd way to produce
unnatural dynamic effects, even if the source material itself passes muster audibly.

>
>>About two years ago we started
>>to notice CDs arriving at
>>radio stations that had been
>>pre-distorted in production or
>>mastering to increase their
>>loudness.
>
>Only TWO years ago???!!!!! As
>far as I'm concerned, the
>sound of popular music CDs has
>been going downhill seriously
>since the widespread use of
>digital dynamics processors,
>after approximately the year
>1990.
>
>Although I do agree that it's
>only been a couple-three years
>since some people learned the
>dumb trick of clipping.
>Uggg... It's just that we
>here on the webboard would
>like to see some esthetic
>improvement that is more than
>just getting rid of a bit of
>clipping at the top.
>

It?s been about two years since I started noticing CDs becoming audibly distorted with
frequent clipped peaks. Wasn?t ?Californication? released about two years ago?

>>We recommend that record
>>companies service stations
>>with radio mixes. These can
>>have all of the equalization,
>>slow compression, and other
>>effects that producers and
>>mastering engineers use
>>artistically to achieve a
>>desired ?sound.?
>
>I'm afraid this leaves you
>wide open to accepting with
>open arms some of the
>incredibly squashed and
>supposedly "radio-ready" mixes
>we're seeing from mix studios
>prior to mastering. May I ask
>for a more radical request---a
>return to decent mixes as well
>as decent masters. Mixes which
>are not so squashed that the
>choruses are just as loud as
>the verses!

I?m inclined to take this in steps consistent with Realpolitik in this industry.
Presumably, the goal here is to preserve a significant amount of the artist?s artistic
vision on the air, consistent with program directors? demands for consistency and
loudness (to avoid having the station ever ?fall off the dial.?) Obviously, if an
artist wants big dynamic contrasts, these will not and cannot be preserved on the
radio because program directors of competitive commercial stations will not stand for
it. Further, the station's desire for a "signature sound" plus source-to-source
consistency requires multiband comprssion that "automatically re-equalizes" material
to the station's target sound. But within these admittedly stringent limitations, it?s
still possible to have an on-air sound that?s punchy and clean, thanks to preservation
of short-term envelope dynamics. In commercial pop music radio, one can preserve a
significant amount of the short-term texture of the original artistic vision, even if
one loses the long-term dynamics and some of the original spectral balance.



Bob Orban


The only question I have is whether the posted capture from Wavelab were taken off of the radio or are they from a purchased disc? It would be interesting to have captures comparing the same passages of the disc to what your boom box actually recieves...
Another thing to consider is whether playback systems are properly calibrated or whther the conversion into wavelab is bit accurate. All I know is that the lack of standards has led us to where we are...out of control....

SoMm

 

[fenix]

well...did i prove my point?

 

[sonicpaint]

I mentioned that in other posts.

I have to agree that things have got'n out of hand with how loud music is on CD's these days. It seems that there is no end to it in the near future though. I think part of the problem is that the average person thinks that a CD that is lower in volume is not as "pro" as the the CD's that are super hot. I can't see that be easy to change. It would be nice to get back to the dynamics of music.

Fenix for real man, I have lost focus on what you are still try'n to prove. What you are recording from the radio just can't be trusted as what is really being broadcasted. That's all that we have said.

If I were to make a radio version of a song of mine I would make it as clean, dynamic and transparent as I could. Then when it get's played, it will sound louder then most an translate better then the rest of the songs that have been compression with a low average to peak ratio.

hope this answers most questions.
sonicpaint

 

[fenix]

Re: I mentioned that in other posts.

Fenix for real man, I have lost focus on what you are still try'n to prove. What you are recording from the radio just can't be trusted as what is really being broadcasted. That's all that we have said.

Sonicpaint:

I think the original intent of this thread was to ask how loud commercial recordings are. I claimed they are generally about -10 to -8 rms. Somehow, you guys think i'm hooking up my computer to a radio and recording a song off the radio which is not the case. I did take a wave file from a commercial recording from a cd and showed you guys how hot it is.

This is like the 2nd or 3rd time I've had to clear this up.

Bottom line:
1. COMMERCIAL ROCK RECORDINGS ARE GENERALLY MASTERED AT -10 TO -8 RMS

2. COMMERCIAL ROCK RECORDINGS OVER A COMMERCIAL RADIO STATION GENERALLY HAVE CLOSE TO 0 RMS.

I hope it's clear now.

 

[Chris Fallen]

Re: Re: I mentioned that in other posts.

Sonicpaint:

I think the original intent of this thread was to ask how loud commercial recordings are. I claimed they are generally about -10 to -8 rms. Somehow, you guys think i'm hooking up my computer to a radio and recording a song off the radio which is not the case. I did take a wave file from a commercial recording from a cd and showed you guys how hot it is.

This is like the 2nd or 3rd time I've had to clear this up.

Bottom line:
1. COMMERCIAL ROCK RECORDINGS ARE GENERALLY MASTERED AT -10 TO -8 RMS

2. COMMERCIAL ROCK RECORDINGS OVER A COMMERCIAL RADIO STATION GENERALLY HAVE CLOSE TO 0 RMS.

I hope it's clear now.

Are you taking into account the radio mixes and not the commercial ones released on the cds? I know they're mixed differently but I don't know how differently.

 

[sonicpaint]

I know what you meant.

I know what you meant and that's where I don't agree. So let's just forget this topic now. You have your thoughts on how things are and I have mine. So just let it be.

sonicpaint

 

[jake-owa]

Now who can pee farther?

 

[fenix]

Re: Re: Re: I mentioned that in other posts.

Are you taking into account the radio mixes and not the commercial ones released on the cds? I know they're mixed differently but I don't know how differently.

I use to work at a radio station and rarely were the singles a different mix than what was released on the cds.

 

[Chris Fallen]

Re: Re: Re: Re: I mentioned that in other posts.

I use to work at a radio station and rarely were the singles a different mix than what was released on the cds.

Actually I meant mastered, but you'll probably still say there weren't many. When I had a class with some mastering guy he gave us examples of mastered songs for album and then for radio. Hm.