Re: [MLUG - DISCUSSION] "optical digital sound cards" OR "what's the best way to play MP3 files on stereo system?"

[Mike Miller <EMAIL:PROTECTED>]

On Sat, 1 Sep 2007, Stephen Montgomery-Smith wrote:

> Some people claim that they can hear the difference between MP3 and WAV 
> (i.e. CD) recordings, because with MP3 compression there has to be some 
> kind of loss of data.  So maybe by using MP3 you have already lost any 
> advantage that optical output might bring.
>
> But really I don't know.


I can tell that you are new to this, but what you've said about lossy 
compression is definitely true.  The thing is, MP3 is not just a single 
way of encoding audio data, there are lots of choices.  One of the most 
important choices is the bit rate.  If you have a high enough bit rate, no 
one will ever be able to distinguish MP3 from audio CD.  With a low bit 
rate, they are distinguishable, and if you go low enough with the MP3 bit 
rate it is trivial to tell the difference.

A lot of everyday MP3 encoding is done at 128 kbps.  That will be 
excellent for many audio tracks on most playback equipment, but sometimes 
you'll hear a bit of phasing artifact (that's what I call it, not sure of 
the technical term).  It's a distinctive sound and it can be annoying. 
For me, I use a variable bit rate in the range from 160 kbps to 224 kbps 
and that seems to work great -- great because I have never been able to 
tell the difference between the copy and the original and because it is 
still reasonably good compression.  I've never heard of a blind test where 
anyone could tell original CD audio from MP3 encoded at 320 kbps, so 320 
kbps seems like a good choice but the files are much bigger than I need. 
Most people who can claim to tell differences might be imagining things -- 
this is the sort of thing where strict blinding and randomization is 
essential.

Another popular format is FLAC (free lossless audio codec) which, as you 
can infer from the name, is lossless.  It's a good encoding scheme but it 
takes up about four times the volume of my MP3s.  It is true that storage 
costs continue to plummet, but there is more cost to the FLAC than that: 
I find that if I play back a FLAC file while doing other things on my 
computer, it will stick a little because the CPU can't keep up with all 
the work, but with MP3 that never happens.  Again, I can't hear a 
difference between my 192 kbps MP3 and the FLAC (except when the FLAC is 
sticking and sounding bad), so I just use MP3.

Mike

_______________________________________________
discussion mailing list
EMAIL:PROTECTED
http://mlug.missouri.edu/mailman/listinfo/discussion