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GeeYouEye
May 9, 2006, 09:44 AM
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?



iGary
May 9, 2006, 09:50 AM
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?

GeeYouEye
May 9, 2006, 11:48 AM
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.

iGary
May 9, 2006, 11:54 AM
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?

gekko513
May 9, 2006, 12:27 PM
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.

GeeYouEye
May 9, 2006, 01:06 PM
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.

min6characters
May 9, 2006, 01:21 PM
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.

GeeYouEye
May 9, 2006, 01:56 PM
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):

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

GeeYouEye
May 9, 2006, 01:59 PM
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.