cd audio to mp3 & volume

[mito]

I've noticed some mp3 volumes are high and thus some sounds are distorted. Looking at the Level or Peak Meter of my nvidia soundstorm, the red level is reached constantly.


Are those songs originally distorted from the source cd or did someone mess with some setting during the ripping process?

 

[silence]

during the ripping process?

hmmm...sounds like possible explenation......

 

[Diplo]

I doubt very much they were distorted on the original recording as no professional mastering would allow this (though a lot of mastering of modern recordings do use a large degree of compression/brick-wall limiting to make them sound loud which can clip the transients). Therefore I would guess someone has tried to normalise the recordings and introduced clipping in the process (some CD ripping software attempts to do this automatically). Given that most masters peak at (or very near) to 0dB it's a bad idea to try and normalise these tracks.

 

[mito]

I doubt very much they were distorted on the original recording as no professional mastering would allow this (though a lot of mastering of modern recordings do use a large degree of compression/brick-wall limiting to make them sound loud which can clip the transients). Therefore I would guess someone has tried to normalise the recordings and introduced clipping in the process (some CD ripping software attempts to do this automatically). Given that most masters peak at (or very near) to 0dB it's a bad idea to try and normalise these tracks.

What does "normalizing" mean in the above context?

Thanks...

 

[Diplo]

What does "normalizing" mean in the above context?

Normalising, in audio terms, means taking the peak amplitude (volume) and raising it to 0dB (or close) and then using that as a reference point to automatically increase the amplitude of the rest of the wave relative to that. In other words it raises the volume of the sound wave as high as possible without introducing clipping. One of the reasons to do this is if you are making a compilation CD and want to make sure that tracks from different sources have roughly the same loudness at the same volume level. More sophisticated techniques will use compression to make the apparent volume seem even louder.

If you're interested in the technicalities try reading this paper.

 

[t0y]

The fact that the meters reach red doesn't automatically mean the sound is distorted. It just means that, like diplo said, most CDs have the sound mastered to close to 97% of the peak level an that reaches red in most meters. If you have red in your master output meter OTOH, means you may have your volume cranked up too high.

But I believe the problem is broken/low quality mp3 encoding... If you're really worried about it maybe you can post/send a sample?

 

[mito]

Sample 1 (dual stereo 320kbps) - with distortion

Sample 2 (192kbps) - lower volume without distortion

 

[t0y]

Are you sure the 2nd one doesn't have distortion? I don't have golden ears, but both songs sounded very similar in terms of sound quality.
I did notice some clicks one the first sample and, in some places, it reaches 0dB but the usual graphical distortion artifacts don't show up, though (or I missed them)...

 

[mito]

Are you sure the 2nd one doesn't have distortion? I don't have golden ears, but both songs sounded very similar in terms of sound quality.
I did notice some clicks one the first sample and, in some places, it reaches 0dB but the usual graphical distortion artifacts don't show up, though (or I missed them)...

The distortion I'm referring to occurs in the beginning of sample 1: that bass beat seems distorted.

 

[mito]

Still in doubt as to the distortion factor. I am comparing both versions of Erasure's Nightbird...

The Dual Stereo 320kbps is hifi, however, I feel distortion in some instruments.

 

[t0y]

I have to say that I still haven't noticed any difference.

How did you record the samples? Maybe you got them from the internet...
I'm 99% sure that some processing other than compression has been done since the first simple is normalized to the max volume (not common in commercial CDs), and the second one's volume is too low.

 

[mito]

I have to say that I still haven't noticed any difference.

How did you record the samples? Maybe you got them from the internet...
I'm 99% sure that some processing other than compression has been done since the first simple is normalized to the max volume (not common in commercial CDs), and the second one's volume is too low.

I got both samples from torrent.

regarding the distortion issue, don't you notice it on your speakers' woofer when listening to sample 1's beat bass?

 

[t0y]

No. I'm using cheap closed headphones.
Do you get the same effect if you turn up the volume on sample 2 to approximately the level of the first one?

Distorting speakers may also be a symptom of pushing them too far....

 

[_xxx_]

The Dual Stereo 320kbps is hifi, however, I feel distortion in some instruments.

That's nowhere near being hi-fi. It's essentially normal stereo@160 kbps.