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Louder kicks on CDs?
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View this Thread in Original format
| Aquarian |
I just received some of the singles I ordered last week. There's something I noticed... Whenever I hear a track on mp3 (good quality renders) and then hear it on CD, I notice a big difference in frequencies. Specifically, the kick drums on the CD versions seem almost twice as loud as any mp3, and the low frequencies in general seem to take alot more space. Why is that? Is it just the way CDs are mastered? Or maybe the way my computer reads them?
It kinda bugs me because I like the mp3 sound better (I know, it's weird isn't it?). I know I can just EQ the lows down.. but it still bugs me! :conf:
Also strange is that I only hear this on trance tracks. Psy or house tracks don't seem to have any difference. |
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| SYSTEM-J |
| Well, MP3s compress sound by chopping off bits of the signal- the bits you're least likely to notice. Usually this is the very highest and lowest sounds. The lower the bitrate of the MP3, the more bits get chopped off to compress it. However, this reduction in sound quality is usually only noticable at very high volumes (on a club system you'd notice a low quality MP3). So it's possible that you're hearing this, but if so I'd turn your stereo down for the sake of your neighbours. |
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| Djeebie |
| quote: | Originally posted by SYSTEM-J
However, this reduction in sound quality is usually only noticable at very high volumes (on a club system you'd notice a low quality MP3). |
You will also notice this at home, but it depends on your home stereo. On a club system even a 320 mp3 will sound not as good as a .wav. 95% of the dancefloor won't notice it though, because the differences are not that big. |
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| Aquarian |
| quote: | Originally posted by SYSTEM-J
Well, MP3s compress sound by chopping off bits of the signal- the bits you're least likely to notice. Usually this is the very highest and lowest sounds. The lower the bitrate of the MP3, the more bits get chopped off to compress it. However, this reduction in sound quality is usually only noticable at very high volumes (on a club system you'd notice a low quality MP3). So it's possible that you're hearing this, but if so I'd turn your stereo down for the sake of your neighbours. |
Actually, my volume is pretty reasonable. Plus, I thought the frequencies being cut were mostly in the top highs. This is like the ~100hz range here, not bottom-low. |
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| Mike_Foyle |
| quote: | Originally posted by SYSTEM-J
Well, MP3s compress sound by chopping off bits of the signal- the bits you're least likely to notice. Usually this is the very highest and lowest sounds. The lower the bitrate of the MP3, the more bits get chopped off to compress it. However, this reduction in sound quality is usually only noticable at very high volumes (on a club system you'd notice a low quality MP3). So it's possible that you're hearing this, but if so I'd turn your stereo down for the sake of your neighbours. |
it wouldnt make a difference that significant im pretty sure.
i would say its most likely to be the hardware that you are playing the cds on. if you are just using your computer to play them then i honestly have no idea lol. |
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| toffy |
If i have correctly understand you, is exactly what i am studyng atm.
The Nyquist Theory says that if we sample at the double of a frequency we can recover the signal up to that frequency, so thats why Audio Cds Sample Rate is 40 khz, to recover up to 20 Khz and reproduce the audio signal as accurate as possible (Accurate for human ears is from 20Hz to 20Khz).
If you talk about double frecuency in a volume sense, forget what i said and think that is the master process what makes it being so loud lol |
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| kush paintings |
| On a dance floor do you think the average club goer would notice the difference between a 192 mp3 and CD quality. |
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| Mike_Foyle |
| quote: | Originally posted by kush paintings
On a dance floor do you think the average club goer would notice the difference between a 192 mp3 and CD quality. |
no, unless its a badly encoded mp3. |
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| meneedit |
the thing about mp3s is, on small crap speakers a 128 sounds normal. On big speakers you can quite easily tell that the hihats sound all watery. and yeah i can easily tell the difference
now on topic for the original post. If you are just listening on your computer.... tell us what sort of sound card you have. Some of the older sound cards play CDs differently to WAVE/MP3 content. also get the latest driver for your sound card if its an oldy. |
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| Subtle |
| quote: | Originally posted by Nou
Where does it say that about Redbook? The rate that its sampled at has nothing to do with the frequency range it represents. Also, the sample rate is 44.1khz not 40khz.
Mp3 just dosnt lop frequencies off left and right (err high and low :p), it does perceptual compression, it will get rid of frequencies that are drowned out by louder sounds or other frequencies. This can happen anywhere in the human hearing range. |
O RLY? i thought it was the high frequencies :o |
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| MelonBoy |
| quote: | Originally posted by Nou
Where does it say that about Redbook? The rate that its sampled at has nothing to do with the frequency range it represents. Also, the sample rate is 44.1khz not 40khz. |
Look for Nyquist and his Theories. Under the 44.1Khz wouldn't be possible to listen to any digital-format music with some quality. Engineering says so. |
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| b i n k u n |
hope this helps.
basic mp3 compression consists of:
step1) frequency compression: drops off bits corresponding to music <20Hz and bits >18-20Hz.
step2) perceptual compression: drops off bits of music that is not as loud as other bits so u lose dynamic range
step3) time compression: drops off bits of music that is <2ms (or 5, i forget the magic number) in which your ear is unlikely to notice. i.e. after a piercing hi-hat, you won't notice that there is a melody in there until 2ms later, so it just drops off that melodic bit of music.
these are the basic steps, there's plenty of other quantization and coding depending on your compressor. and depending on your bitrate, the cutoffs for the above are altered. don't believe, go research on www.mpeg.org (u want mpeg audio layer 3 which is the true name for mp3) or the fraunhofer institute, i believe they developed the technology. (http://www.iis.fraunhofer.de/index.html)
and yes, CD redbook was set to sample at 44.1kHz cuz of the Nyquist Theory...half the sample rate is 22kHz, which is a fail safe since we only hear up to 20kHz. any lower than 44.1, and you run the risk of aliasing. DSP 101: http://csunix1.lvc.edu/~snyder/2ch11.html
do your research, it's not that hard to understand. unfortunately, i had to pay to learn all this. :whip: |
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