Distorted Audio When Listening To Device

[spaceways]

I noticed that some of my Hi-SP songs are distorted when listening to my MZ-RH910. My library is ripped from CDs to Hi-SP. I heard distortion with my EQ on and off. I heard distortion regardless of the volume and headphones I am using. I just noticed this problem since I started creating MDs using SS 3.1, but I don't know if that has anything to do with it. Has anyone else had this problem or know why it is happening?

Note: I read a few other posts about distorted MP3 tracks, but again, I am not using MP3. I ripped directly from CD to Hi-SP (ATRAC 256kbps).

Thanks in advance,

Jay

[KrazyIvan]

You might have discovered the music industries quest to get ever closer to zero dB. A lot of newer CD's are recorded so close to 0dB that this distortion occurs. The thing is that you should hear the distortion while listening to your CD's too. If it is not present in the CD's then I would say it is a hardware problem or a problem during transfers. Are you doing other things while you are ripping CD's? What are the specs on your computer?

[spaceways]

You might have discovered the music industries quest to get ever closer to zero dB.  A lot of newer CD's are recorded so close to 0dB that this distortion occurs.  The thing is that you should hear the distortion while listening to your CD's too.  If it is not present in the CD's then I would say it is a hardware problem or a problem during transfers.  Are you doing other things while you are ripping CD's?  What are the specs on your computer?

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You may be right. I will have to check my CDs to see if they distort too. They are newer CDs, so this is possible. I am not doing anything else while ripping CDs or transferring. So, that can probably be ruled out. I just did some testing with Simpleburner and I still hear distortion. I am thinking, as you said, it might be the CD source. I don't think it is the hardware because I also own a 1GB Sony flash player and I just discovered I am hearing the distortion on it too. My computer specs are Windows XP Service Pack 2, 1.41 ghz processor, 256 RAM, Sonicstage 3.1.

One other thing I have yet to try is transferring 256kbps MP3s (ripped in LAME) to MD and see if I hear distortion. In a previous test, I noticed that the volume of the MP3s seemed lower, which may be the ripping programs attempt to reduce the DBs to a less-distorted level.

[dex Otaku]

Many lossy compression schemes have difficulty converting signals that ride the 0dBfs margin.

Most albums produced since the late 1990s are "bit-pushed", i.e. compressed and limited to make the overall volume of the content louder during playback. On normal equipment [i.e. a CD player] this doesn't cause a problem.

Note that I'm using two meanings of "compression" here. First, that of dynamic range compression [the traditional audio term], which at its extreme is known as limiting; this is how AGC works when recording. The second type of compression is data compression, which is the blanket term for everything from lossless packing [such as MLP used on DVD-Audio and FLAC] to lossy encoding like Atrac and MP3.

Highly-compressed content, rather than consisting of sounds that have an actual dynamic range, is basically made up of a series of extreme transients.

Virtually all lossy encoding formats have difficulty with extreme transients.

During encoding, these can cause many problems, usually showing up as pre-echo or ringing - things that all ATRAC formats are known for having audible difficulty with, as with the infamous "castanets" test.

During decoding, the same highly compressed material will often show up as straight-out clipping distortion [which it almost, but not quite, is to begin with]. This is likely what you're hearing.

MP3 is also known to have the same problem, hence the reasoning behind peak-normalising recordings to 98% of 0dBfs before encoding.

LAME doesn't often have this problem, by my experience. This is probably due to its tweaked filtering and encoding algorithms.

If the music you're having problems with does this on a consistent basis, I'd suggest ripping the entire album to WAV with a program such as Exact Audio Copy, which can do the peak-normalisation on the fly as per settings that are easily accessible in its preferences. If you rip an entire album as a disc image with cuesheet while normalising, you can then make a disc image with a program like Nero Burning ROM that will load with its Imagedrive utility, giving you access to the image as if it were still a CD, meaning that SonicStage or Simple Burner can find it in the CDDB and still give you all the tags correctly.

[spaceways]

Many lossy compression schemes have difficulty converting signals that ride the 0dBfs margin. 

Most albums produced since the late 1990s are "bit-pushed", i.e. compressed and limited to make the overall volume of the content louder during playback.  On normal equipment [i.e. a CD player] this doesn't cause a problem.

Note that I'm using two meanings of "compression" here.  First, that of dynamic range compression [the traditional audio term], which at its extreme is known as limiting; this is how AGC works when recording.  The second type of compression is data compression, which is the blanket term for everything from lossless packing [such as MLP used on DVD-Audio and FLAC] to lossy encoding like Atrac and MP3.

Highly-compressed content, rather than consisting of sounds that have an actual dynamic range, is basically made up of a series of extreme transients. 

Virtually all lossy encoding formats have difficulty with extreme transients.

During encoding, these can cause many problems, usually showing up as pre-echo or ringing - things that all ATRAC formats are known for having audible difficulty with, as with the infamous "castanets" test.

During decoding, the same highly compressed material will often show up as straight-out clipping distortion [which it almost, but not quite, is to begin with].  This is likely what you're hearing.

MP3 is also known to have the same problem, hence the reasoning behind peak-normalising recordings to 98% of 0dBfs before encoding.

LAME doesn't often have this problem, by my experience.  This is probably due to its tweaked filtering and encoding algorithms.

If the music you're having problems with does this on a consistent basis, I'd suggest ripping the entire album to WAV with a program such as Exact Audio Copy, which can do the peak-normalisation on the fly as per settings that are easily accessible in its preferences.  If you rip an entire album as a disc image with cuesheet while normalising, you can then make a disc image with a program like Nero Burning ROM that will load with its Imagedrive utility, giving you access to the image as if it were still a CD, meaning that SonicStage or Simple Burner can find it in the CDDB and still give you all the tags correctly.

←

Thanks Dex. This is excellent information. I will do 2 things: 1) Transfer a 256kbps MP3 version of the album encoded in LAME to my Hi-MD player. 2) Try ripping the entire album in WAV with peak-normalisation.

Hopefully Sonicstage will offer peak-normalising in the future - it seems that it is a necessary option. If so, I assume that I would have to re-rip my entire library (ugh) unless they offer it as an on-the-fly option.

[KrazyIvan]

If the music you're having problems with does this on a consistent basis, I'd suggest ripping the entire album to WAV with a program such as Exact Audio Copy, which can do the peak-normalisation on the fly as per settings that are easily accessible in its preferences.  If you rip an entire album as a disc image with cuesheet while normalising, you can then make a disc image with a program like Nero Burning ROM that will load with its Imagedrive utility, giving you access to the image as if it were still a CD, meaning that SonicStage or Simple Burner can find it in the CDDB and still give you all the tags correctly.

←

Good info, I did not think to do this. I don't have very many CD's with this problem. A lot of my CD's are pre-1992. The one or two that do exhibit this behavior are almost impossible to listen to in my Sony ES and JVC CD decks. I am going to try this out in order to rescue those discs. Thanks!

[Guest NRen2k5]

The easiest way to prevent the distortion is just to do realtime optical dubs, and set the recording volume lower than normal.

[dex Otaku]

Good info, I did not think to do this.  I don't have very many CD's with this problem. A lot of my CD's are pre-1992.    The one or two that do exhibit this behavior are almost impossible to listen to in my Sony ES and JVC CD decks.    I am going to try this out in order to rescue those discs.  Thanks!

←

Woo. If the discs are older than 1992, the chances are basically nil that this is in fact the issue.

The issue is more likely to be that the discs themselves are dying. They might work in a standalone player [which only reads at 1x speed] but any attempt at ripping will exhibit the full effects of bit rot.

I have 400+ CDs, with maybe 1/2 of them made before 1995. Only two exhibit bit rot; it first showed up as swishing sounds [obvious distortion] on most players. Now they are completely unplayable [sound much like a data CDR put in a player that doesn't recognise such discs for what they are and auto-mute or refuse to play].

[KrazyIvan]

Woo.  If the discs are older than 1992, the chances are basically nil that this is in fact the issue.

The issue is more likely to be that the discs themselves are dying.  They might work in a standalone player [which only reads at 1x speed] but any attempt at ripping will exhibit the full effects of bit rot.

I have 400+ CDs, with maybe 1/2 of them made before 1995.  Only two exhibit bit rot; it first showed up as swishing sounds [obvious distortion] on most players.  Now they are completely unplayable [sound much like a data CDR put in a player that doesn't recognise such discs for what they are and auto-mute or refuse to play].

←

I think I may have mis communicated. The discs that I have from 1992 sound perfect. THey are in pristine condition and rarely see the light of day because I use my CD-R backups. It is the newer discs that I have purchased recently that sound awful. Only two of them though.

NRen2k5: OPtical dubs do not solve the problem. The distortion is in the original recording. So, it shows up in the optical dubs.

[spaceways]

Thanks for the info.

Edited June 13, 2005 by spaceways