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jwb · Posted - Tue Sep 18, 2001 1:00 pm

Hi there,

I'm archiving my vinyl. I process each lp and single and write the best to a cd. The rest is archived by encoding it to mp3 format and burn them on a cd for when I want them.

I use a bitrate of 128.

I am however puzzled. When I wanted one of the mp3's I noticed that there was some kind of distortion introduced on all of them. It's a kind of clipping grainy sound which only affects the vocal part. However CE reports no clipping. And it's only present on recorded and archived vinyl, not other encoded waves. The waves themselves don't have this problem either, but off course the decoded mp3's do.

Does anyone know what this is and how to get rid of it.

Digital greetings,
JWB

2Bdecided · Posted - Tue Sep 18, 2001 1:30 pm

mp3 at 128kbps isn't CD quailty :-(

mp3 at 128kbps is actually pretty poor quality. Most music pirates are using 192kbps these days, and the smart folks are using high quality (high bitrate) variable bit rate encoding.

The possible reason you notice encoding distortion on your vinyl transfers is that vinyl contains much more background noise than CD or a typical live recording. This means, when the encoder is trying to decide what information to throw away (you realise 128kbps mp3 throws away 90% of the information?), it has a harder job keeping the parts you can hear, because the background noise confuses it.

Solution: use a higher bitrate. 256 is pretty near perfect - mp3 is never truly CD quality, but for most people and most tracks, 256kbps is transparent. 128kbps just isn't enough - sorry. Unfortunately there's not much you can do about the encoding noise on a 12kbps mp3 if you've deleted the original .wav.

Cheers,
David.
P.S. http://www.r3mix.net has a lot to say about this subject, as does http://www.fastforward.iwarp.com/

SteveG · Location: United Kingdom

Not all MP3 coders are equal! On the better ones, where you get a choice, you will always get a cleaner result by using the longest conversion time. When I tested this, the difference was quite clear, and you could certainly call the quick conversions 'grainy'.

So it may be as simple as that...

Steve

Cliff Sloane · Posted - Tue Sep 18, 2001 3:56 pm

The MP3 plugin for CE works extremely well and quickly, IMHO. I compared frequency responses in Analyze.. mode and it came closer to the WAV than Lame did.
David is correct, of course, about bitrates. I suggest saving a WAV file as a high-quality VBR MP3 and see if that makes a difference. You can even do it as a batch file and let it run while you sleep.

beetle · Location: USA

I also suggest using the VBR, or "Variable Bit-Rate". This lets you get away with a somewhat smaller file while retaining more information than a regular CBR mp3, and sounds fuller.

Most mp3 players should be able to handle them.

Graeme · Member Location: Spain

Moving off at a slight tangent, I would query the the word "archive" and the designation MP3 being used together.

Plenty of archival experts are at odds over digitising in the first place and the thought of using a lossy compression algorithm, such as MP3, is pure anathema to them.

beetle · Location: USA

Graeme, he has already said that he burns the best to CD-R first.

To add, IF and when I do need to archive something on the HD, I look for alternate compressed formats like Monkey's Audio and SF's Perfect Clarity even IF my original format was mp3. I don't like to resave ANYTHING to mp3 for a second time.

2Bdecided · Posted - Wed Sep 19, 2001 4:50 am

The slow (High Quality) setting in the MP3-me plug-in for CEP sounds terrible, especially at 128kbps. It has some kind of bug.
http://fastforward.iwarp.com/alternbug.html
Later implementations of this codec (e.g. Music Match Jukebox 6) don't have the bug, and the slow codec is excellent. MMJB doesn't give you the features of the CEP plug-in though. I hope Synt take note and release a patch for that plug-in soon!

People use the word "archive" in the most rediculous ways - I've given up arguing against it. If you're really "archiving", then you should use an open source lossless format (e.g. LPAC) and store the LPAC source on the disc too - so that when Windows PCs are long forgotten, you'll still be able to decode your files (if you can code). That sounds a bit melodramatic - but that's the whole point of archiving - it's got to be safe and future proof.

Cheers,
David.
http://www.replaygain.org/

beetle · Location: USA

LPAC???? What's that?

SteveG · Location: United Kingdom

Graeme · Member Location: Spain

2Bdecided · Posted - Wed Sep 19, 2001 7:25 pm

Monkey's audio is lossless - like Winzip.

Having suggested LPAC, I have to admit that I don't use anything to compress - I just burn the .wavs to CD-R in CD-ROM mode.

In this case, it's just raw samples with a .wav header - should be no problem playing this back any time soon. I can even play my old Atari ST sample discs by reading the raw data, so I reckon my CD-Rs will be safe a few years yet. Nearest to "archive" I can manage.

Cheers,
David.
http://www.David.Robinson.org/