OK, so I'm downloadin' tunes and I go back to listen to them and every once in a while in an MP3 there will be this quick screech type sound, you guys know what I'm talkin' about? It's in enough songs that I can identify that it's some sort of problem with the format itself, not just a particular song, but it ticks me off.

Also, do you know what quality download is the same as CD quality? Is it 128?

Thanks guys

Andrew

 

The sound ur referring to might be bad recording/ripping..

as for quality.. 128 is nowhere close to cd quality, 320 is like the best u can rip.. but the only way to get cd quality is to rip it as a wav file i think.. winamp'll show a different type of quality rating, i forgot wut it was but it wasn't just a numerical bitrate, it had a number in it. put an actual audio cd in, play and winamp, and u'll find out.

 

The sounds you're hearing are compression errors. These can occur for a lot of reasons. Some of them include when the CD player can't keep the stream of info going to the CPU, when the CPU is overworked and trying to continue encoding, a write error to the HD/RAM, and so on. I've ripped about 2000 mp3s on my computer, and I'd say 1 in 20 turns out like crap. I use audiocatalyst, which is based on Xing's very fast compression algorithm. Probably not the best quality encoding, but it's fast - and the flipside of that speed is that sometimes the encoding turns out like crap. The best way to avoid this is to write to a wav file first, then encode that, which negates any sort of speed advantage. I haven't looked at different software lately, so chances are there is something better available.

"CD quality" is a very subjective number. MP3 is a lossy compression, meaning it reduces the file size by eliminating data. What gets eliminated is the result of aural studies done years ago. The original mp3 codec dropped frequencies over 16000 Hz and under 40 Hz (I believe those were the numbers), because most people couldn't really hear/appreciate their prescence in the music. The revised mp3 codecs have altered what gets dropped, and that is affected by the bitrate as well.

That said, 128 is *not* CD quality, it never was, and it never will be. 192 is probably the lower limit of what could be considered "CD quality" while still maintaining a reasonable compression ratio. A CD (essentially a .wav file) is recorded at about 1160 kbps, so 128 is about 9:1 compression and 192 is about 6:1. My latest burned mp3 cd has 580 minutes of music (on an 80 minute/700 meg disc), which is 7.25:1 average compression - indicative of the mix of 128 and 192 on it.

 

I think he just needs to replace his old needle.

 

Wow, thanks WestSide, Ludatic.

I need a whole new turntable Viper...lol.



Andrew