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Clipping waveform on a CD - Why?

post #1 of 26
Thread Starter 

Hello,

 

After bringing a new DAC into my headphone setup at work (Music Fidelity MA HPA + M1 DAC) I went crazy yesterday after listening to a new CD. The misses has asked me to come along to the impending Pink concert so I thought I had better listen to a few CDs just so I know what to expect as is is not one of my preferred Artists.

 

So, part way through the CD I swear I'm going crazy and I'm hearing some strange distortions and keep jumping back to my favorite auditioning tracks to make sure I don't have a setup problem. The end of a long story is that I open up the track in Sonic Visualizer and straight away I can see the waveform clipping off the top. Now, I have then started reading about the Loudness War and where this has all come from but here is my question and its driven by lack of understanding I think.

 

My headphone rig, although fairly good, I personally i love it, it must be lesser quality than the equipment that sound engineers use. To me the clipping and associated distortion causes some horrific sound to be produced through both my T70's and HD650's. Is it my equipment that is just very unfavorable to this type of mastering or are these tracks tuned for the masses who probably don't have equipment where it is very noticeable?

 

Hope someone can help me understand a little more about sound engineering and the decision process they make as I have never met one to ask the question to, I'm really interested to learn more about their process.

post #2 of 26

Most headphones, even those with just an okay treble response, show no mercy to clipping, clicks and other distortions.

 

Some CDs are just mixed/mastered in such a dynamically compressed and loud way. Adding any more of that would even cause the artist to reject it. redface.gif

 

It's not that mastering engineers are deaf, but they are "asked" to make it LOUDER.


Edited by xnor - 4/8/13 at 5:05pm
post #3 of 26
Thread Starter 
So I'm assuming that it is just done because it has been done for so long before.  
 
I have a feeling that I'm about to go down a rabbit hole trying to research and understand something that is just done because everyone else does it.  Somewhat akin to banging your head on a wall repeatedly and expecting a different outcome I suppose blink.gif
 
Cheers for your input
post #4 of 26

dynamic range compression has been a electronic music effect for as long as we have had audio electronics

 

it is "the sound" of some instruments at this point

 

digital lets you dial it up

post #5 of 26

After a quick look even a half a dB louder song will sound better. So managers tried to always exceed their competition. Think of the mastering engineer being requested to produce something that is at least as loud as X or Y. The result, after a couple of years, is what you described above.

 

 

Also see videos like this:

post #6 of 26
Thread Starter 

Ah many thanks for the video, this is some great information.

 

So there are ways to assist in my personal listening, such as choosing an amp that doesn't emphase this processing.  I'm starting to understand more about what this sound is and how to manage it for how I want to listen to music.

 

Again, thanks for helping bridge my gap in understanding about this and its effects to the sound.

post #7 of 26

And dont forget TV adverts sounds okay watching a film -ad comes on and  you are diving for the remote  

    They get away with it by saying  the actual level hasnt changed But its done on purpose for obvious reasons.
 

post #8 of 26
Thread Starter 
I did not even think to apply this thought process to TV. It makes sense why they do it but your absolutely right, it always annoys me that loudness isn't normalized across film and their adverts.

Thanks all for posting, I have learned a bit more about sound engineering.
post #9 of 26

The more compressed the less variation in RMS level. In a film an action scene might be louder than a commercial but overall the average RMS level is much lower. This is why such commercials are so annoying, and compressed music fatiguing.

 

I dunno what you're doing overseas about it but here in Europe we have the EBU R128 loudness normalization. No more turning down volume for commercials because that happens automatically. The more compressed the commercial, the higher the "penalty".

This should be enabled by default on any device that can play music. Like the audio player foobar2000 that has implemented ReplayGain based on R128. wink.gif

 

edit: from Germany's public broadcaster ARD (translated with Google...):

- Highly compressed commercials sound much worse compared to "properly" produced ones - especially after the loudness normalization.

- These spots may lose their effect in the environment of dynamically produced material because their soundwise weaknesses are more noticeable.
- Dynamics is a fundamental design feature.
- By using excessive compression this feature is eliminated, thus an essential factor for achieving sound quality is not used.
- Loudness normalization allows for very dynamic mixes of all sorts of sounds. Such dynamic sounds usually are superior to highly compressed material - with the same impression of loudness.


Edited by xnor - 4/9/13 at 3:18pm
post #10 of 26
Quote:
Originally Posted by xnor View Post

The more compressed the less variation in RMS level. In a film an action scene might be louder than a commercial but overall the average RMS level is much lower. This is why such commercials are so annoying, and compressed music fatiguing.

 

I dunno what you're doing overseas about it but here in Europe we have the EBU R128 loudness normalization. No more turning down volume for commercials because that happens automatically. The more compressed the commercial, the higher the "penalty".

This should be enabled by default on any device that can play music. Like the audio player foobar2000 that has implemented ReplayGain based on R128. wink.gif

 

edit: from Germany's public broadcaster ARD (translated with Google...):

- Highly compressed commercials sound compared to "properly" produced ones much worse - especially after the loudness normalization.

- These spots may lose their effect in the environment of dynamically produced material because their soundwise weaknesses are more noticeable.
- Dynamics is a fundamental design feature.
- By using excessive compression this feature is eliminated, thus an essential factor for achieving sound quality is not used.
- Loudness normalization allows for very dynamic mixes of all sorts of sounds. Such dynamic sounds usually are superior to highly compressed material - with the same impression of loudness.

 

Once iTunes adopts R128 the party is over for music labels/producers. I only say that because of the widespread nature of iTunes, and the fact that many albums are mastered specifically for iTunes distribution. All their compression tricks will be for naught, and the urge to out-level the competition will only result in the producer/engineer shooting his own master in the foot. Hoisted by their own petards! Hah!

post #11 of 26
Thread Starter 
So as mentioned in the video and again by last post, things will slowly return to the way it was with dynamic sound and therefore better sounding (in my opinion) music. This I look forward to and hope its here sooner rather than later.
Edited by Autobat - 4/9/13 at 6:33pm
post #12 of 26

Shouldn't a preamp gain of say -30 dB fix all the digital clipping issues? Of course you have to turn the volume much louder, but that's another thing.


Edited by Kaffeemann - 3/1/14 at 12:02pm
post #13 of 26

I found my first example of clipping on a classical CD the other day. It was a Mozart flute concerto. In peaks of the solo flute, it started having a repeating thud sound mixed in. At first I thought it was my AAC encode, but I pulled the original CD and sure enough, it was on there too.

post #14 of 26
Thread Starter 
Yes, sadly if your source is clipped the the data is lost. If only we could get hold of the master recordings!
post #15 of 26

A file will only clip if it exceeds 0 dBFS. 

 

This is a song with lots of clipping:

 

 

Now, if you apply -30dB of preamp gain things start to look different:

 

Also, the difference in sound qulity is quite obvious. Voices finally sound like voices and not like chainsaws.


Edited by Kaffeemann - 3/2/14 at 2:32am
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