[stv014]

  It's probably already been mentioned a hundred times in this thread, but for some reason 24 bit albums are mastered differently. Does anyone know why exactly?

 
Because they target different markets. It has nothing to do with any technical limitations of the formats. The high dynamic range "audiophile" version would still sound fine converted to 44.1/16 Red Book format, but it would be then less obvious to the casual consumers why they would want to buy it (again).

 

[stv014]

  So people claiming to hear a difference based on the different mastering, are BS-ing?

 
If the mastering is different, they can of course hear a real difference, and the "high resolution" version is indeed usually better. Just do not confuse correlation and causation, the mastering is not always different, and when it is not worse for the CD quality track, it can actually sound great, too.

 

[UltMusicSnob]

Without knowing if this is ever the case, I can imagine at least one reason for mastering differently. I recently took a track I'd created with *lots* of bass energy into a large auditorium with very poor speakers--lucky I did not destroy them with this track. They were flapping and banging for a second there, before I hit the volume and dialed it way back. 
  I have another assignment now that will have to be played in that same venue, and I'm going to pull everything below 60 Hz, and attenuate everything up to at least 120 Hz. I'll test it onsite beforehand, but I expect to have to give a little hype to the harmonics of the instruments so effected, in order to give an impression of sufficient volume, but without actually hitting the fundamental hard.
  If I had "audiophile" as my target market, I would assume as a mastering engineer that my listeners will have equipment with full extension and good detail, so I could master without these sorts of workarounds. 

 

[xnor]

I don't know if you know dubstep, but there are tracks with pretty low bass (~35 Hz) and LOTS of it. I mean completely overpowering amounts. You can find such tracks on ordinary CDs.
 
 
I would understand this for a "radio edit/version", but for normal CD botching the sound sounds like a cheap excuse to me.

Of course I'm not saying this never happens.

 

[Marleybob217]

  I don't know if you know dubstep, but there are tracks with pretty low bass (~35 Hz) and LOTS of it. I mean completely overpowering amounts. You can find such tracks on ordinary CDs.
 
 
I would understand this for a "radio edit/version", but for normal CD botching the sound sounds like a cheap excuse to me.

Of course I'm not saying this never happens.

Why not? Wav only goes to 40hz? I think you are confusing mp3 to wav/flac, mp3 does cut of the inaudible frequencies if I'm not mistaken. And 35hz is very much audible.
 
I know professional DJs that sometimes use 320kbps files in clubs. It works fine really. They have the gear to actually play those sub-bass frequencies, and it is still very much present.

 

[stv014]

Quote:

  Why not? Wav only goes to 40hz?

 
You did not read carefully enough:

  You can find such tracks on ordinary CDs.

 
Of course, CDs (and in fact anything in PCM format) can go down to 0 Hz. There is only an upper limit.

 

[xnor]

Indeed, the lower "limit" is 0 Hz = DC. In practice you won't find much content below ~20 Hz on CDs though.
 
@Marleybob217: I was responding to UltMusicSnob's post that, if I understood it correctly, CDs are supposedly mastered for speakers that cannot reproduce sub bass properly like filtering out sub bass and boosting mid/upper bass.
 
Besides my example above, DAPs often come with in-ears nowadays that can reproduce sub bass quite well.

 

[UltMusicSnob]

  Indeed, the lower "limit" is 0 Hz = DC. In practice you won't find much content below ~20 Hz on CDs though.
 
@Marleybob217: I was responding to UltMusicSnob's post that, if I understood it correctly, CDs are supposedly mastered for speakers that cannot reproduce sub bass properly like filtering out sub bass and boosting mid/upper bass.
 
Besides my example above, DAPs often come with in-ears nowadays that can reproduce sub bass quite well.

 
 
Actually I was going to a purely theoretical point, that *if* a record company cared to do so, they could tailor mixes to the intended platforms. Didn't mean to imply that it's an actual practice, which actually kind of strikes me as wishful thinking. Anyway, that's a possible reason to master differently that *I* might care about.

 

[MrMateoHead]

Re-Mastering for the sake of protecting equipment seems like a good idea. On the other hand, isn't that what low- and high-pass filters are for?

 

[Baxide]

  Of course, CDs (and in fact anything in PCM format) can go down to 0 Hz. There is only an upper limit.

It's actually 1Hz that CD can go down to.

 

[Baxide]

  Indeed, the lower "limit" is 0 Hz = DC. In practice you won't find much content below ~20 Hz on CDs though.

Far from it. There are loads of tunes with audio information below 20Hz.

 

[stv014]

  It's actually 1Hz that CD can go down to.

 
There is no such restriction inherent to the format itself. It just does not make sense to record very low frequencies for the purpose of music playback.

 

[Digitalchkn]

It's actually 1Hz that CD can go down to.

DC could indeed be captured showing up in the waveform plot as a constant offset from center.

 

[Baxide]

   
There is no such restriction inherent to the format itself. It just does not make sense to record very low frequencies for the purpose of music playback.

It's not possible to record a DC signal onto a discs. What you can record is a blank space of 0 frequency. This is actually quite common on test discs and is used to measure any signal to noise ratio.

 

[Baxide]

DC could indeed be captured showing up in the waveform plot as a constant offset from center.

Can you give me an example of a disc that has such an audio file on it? I have loads of engineering test and set up discs from CD player manufacturers. But none of them has a signal like you describe. I do have 1Hz as the lowest recorded frequency on a disc. That's as low as it goes.