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GeeYouEye

macrumors 68000
Original poster
Dec 9, 2001
1,670
10
State of Denial
I made a CD for my alarm clock last night out of a variety of songs. The only thing they have in common is that they end up pretty loud. This makes sense; I want to wake up. The format of the songs was mixed. There were some .mp3s, some .m4as, and some .m4p's. The CD seemed to burn all right... a bit slower than usual, and it significantly overestimated the time at the beginning, then began counting down 2-4 seconds at a time, but that was all. When I put the CD in my alarm clock, I found a problem: the AAC (both kinds) tracks converted extremely quietly; if Mr. Jones (MP3, Counting Crows) was loud enough to almost wake up someone next door, Friends will be Friends (.m4a, Queen) wouldn't have woken me up, 3 feet away, if it had been the first song.

I've burned CD's from iTunes for my alarm clock before, and they've never had this problem, although the previous one I burned was in October, so I'd imagine it could be a problem with the current version.

Any thoughts?
 
GeeYouEye said:
I made a CD for my alarm clock last night out of a variety of songs. The only thing they have in common is that they end up pretty loud. This makes sense; I want to wake up. The format of the songs was mixed. There were some .mp3s, some .m4as, and some .m4p's. The CD seemed to burn all right... a bit slower than usual, and it significantly overestimated the time at the beginning, then began counting down 2-4 seconds at a time, but that was all. When I put the CD in my alarm clock, I found a problem: the AAC (both kinds) tracks converted extremely quietly; if Mr. Jones (MP3, Counting Crows) was loud enough to almost wake up someone next door, Friends will be Friends (.m4a, Queen) wouldn't have woken me up, 3 feet away, if it had been the first song.

I've burned CD's from iTunes for my alarm clock before, and they've never had this problem, although the previous one I burned was in October, so I'd imagine it could be a problem with the current version.

Any thoughts?

What bitrate are the songs?
 
Varies from 96-320 in MP3 (all of them are at the proper volume, I'm pretty sure) including 2 VBR, 128 for everything in AAC.
 
GeeYouEye said:
Varies from 96-320 in MP3 (all of them are at the proper volume, I'm pretty sure) including 2 VBR, 128 for everything in AAC.

Well all of those would have different volumes at different bitrates, but are they all the same low volume - even the higher bitrate songs?
 
It could be that the MP3's are what I think is called a radio mix, where the audio is cranked up and then compressed / cut off at the top.

This makes everything sound louder, but you lose the dynamics in the music. It's used a lot by broadcasting because the radio and tv-channels must make their channel get as much attention as possible when people switch by.

A record recording doesn't have to crank the sound waves up in this way to get attention. It's more important to keep the quality.

If you mix radio mixes with record mixes without any volume adjustment, you can get the result you're describing.

I think iTunes adjusts the volumes for you when it plays back clips itself, and perhaps it doesn't do that if you burn to a CD. I'm doing a bit of guessing here, but maybe it'll help to have some more theories to work on.
 
iGary said:
Well all of those would have different volumes at different bitrates, but are they all the same low volume - even the higher bitrate songs?

No, the MP3s are all at the same, normal volume, no matter the bitrate. The AACs are too quiet, whether protected or not.
 
GeeYouEye said:
No, the MP3s are all at the same, normal volume, no matter the bitrate. The AACs are too quiet, whether protected or not.

This may be a stretch (and probably is)... but I had a similar question a while back but regarding playback of songs instead of burning. Songs that had been imported into iTunes after being ripped mp3 format from a separate application sounded much louder than songs I had ripped in iTunes in AAC format when playing back on my iPod. Turns out I had "sound check" turned on, which only impacted those selections that had been ripped in iTunes. When I turned the "sound check" off, the AAC selections were on par with the mp3.

Is it possible you've got sound check turned on? I'm not sure if sound check would have the same impact in burning songs to CD, but it may be worth just looking into. (I guess this assumes the mp3 selections you have were ripped outside of iTunes)

I'd be interested in knowing what you find.
 
gekko513 said:
It could be that the MP3's are what I think is called a radio mix, where the audio is cranked up and then compressed / cut off at the top.

This makes everything sound louder, but you lose the dynamics in the music. It's used a lot by broadcasting because the radio and tv-channels must make their channel get as much attention as possible when people switch by.

A record recording doesn't have to crank the sound waves up in this way to get attention. It's more important to keep the quality.

If you mix radio mixes with record mixes without any volume adjustment, you can get the result you're describing.

I think iTunes adjusts the volumes for you when it plays back clips itself, and perhaps it doesn't do that if you burn to a CD. I'm doing a bit of guessing here, but maybe it'll help to have some more theories to work on.

It's possible, but unlikely. I checked all the songs in the playlist for soundcheck adjustment. It's true that most of the AAC's have a higher-magnitude negative adjustment than most of the MP3's, but that's not exclusively the case, and the exceptions are just as quiet as the rest. Even the one +adjusted MP3 is louder on the CD than any of the AAC's. Additionally, most of the MP3's (like the unprotected AAC's) were ripped on my computer direct from CD. Different versions of iTunes though, FWIW.

Here's a table of the properties of the songs (Volume is the "Volume:" given in the Get Info Window):
Code:
Bitrate/Type    Extension   Encoder         Volume       Source     Status
202kbps/VBR-JS  .mp3        LAME 3.91       -4.8dB       Unknown    Normal
128kbps/SBR-LCS .m4a        iTunes 4.2      -13.5dB      CD         Quiet
128kbps/SBR-LCS .m4p        Apple           -14.1dB      iTMS       Quiet
160kbps/SBR-JS  .mp3        iTunes 1.1      -7.5dB       CD         Normal
128kbps/SBR-LCS .m4a        iTunes 4.6      -8.8dB       CD         Quiet
192kbps/SBR-S   .mp3        Unknown         -6.4dB       Unknown    Normal
128kbps/SBR-JS  .mp3        Unknown         -10.3dB      Unknown    Normal
128kbps/SBR-LCS .m4p        Apple           -12.5dB      iTMS       Quiet
96kpbs/SBR-JS   .mp3        Unkwn(WinAmp)   -6.5dB       CD         Normal
194kpbs/VBR-JS  .mp3        LAME 3.91       -3.4dB       Unknown    Normal
128kpbs/SBR-LCS .m4p        Apple           -12.3dB      iTMS       Quiet
96kpbs/SBR-JS   .mp3        Unknown         -1.0dB       Unknown    Normal
128kbps/SBR-LCS .m4a        iTunes 4.6.0.15 -9.0dB       CD         Quiet
160kbps/SBR-JS  .mp3        Audion(I think) -5.6dB       CD         Normal
160kbps/SBR-JS  .mp3        Unknown         -5.1dB       CD         Normal
128kpbs/SBR-LCS .m4p        Apple           -4.8dB       iTMS       Quiet
128kbps/SBR-JS  .mp3        Unknown         +2.2dB       CD(prbly)  Normal
128kpbs/SBR-LCS .m4a        iTunes 4.7      -8.1dB       CD         Quiet
128kbps/SBR-LCS .m4a        iTunes 4.6.0.15 -1.1dB       CD         Quiet
128kpbs/SBR-LCS .m4p        Apple           -10.7dB      iTMS       Quiet
320kbps/SBR-JS  .mp3        Unkwn(WinAmp)   -11.2dB      CD         Normal

S = Stereo
JS = Joint Stereo
LCS = Low Complexity/Stereo
VBR = Variable Bitrate
SBR = Single Bitrate
 
min6characters said:
This may be a stretch (and probably is)... but I had a similar question a while back but regarding playback of songs instead of burning. Songs that had been imported into iTunes after being ripped mp3 format from a separate application sounded much louder than songs I had ripped in iTunes in AAC format when playing back on my iPod. Turns out I had "sound check" turned on, which only impacted those selections that had been ripped in iTunes. When I turned the "sound check" off, the AAC selections were on par with the mp3.

Is it possible you've got sound check turned on? I'm not sure if sound check would have the same impact in burning songs to CD, but it may be worth just looking into. (I guess this assumes the mp3 selections you have were ripped outside of iTunes)

I'd be interested in knowing what you find.
Sound check is on, but it affects everything, both ripped inside and outside of iTunes.
 
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