Re: [Phys-l] Another technical question

["John Clement" <clement@hal-pc.org>]

As to seriously golden ears, it depends on the individual, and strongly on
the age and experience.  Some MP3 converters produce high frequency ringing
which is audible to younger listeners, but most anyone over 50 or who has
gone to very loud concerts can not hear it.  Sometimes artifacts can be very
obvious, and other times very inobvious.  It isn't like audio tape which
adds harmonic distortion which is pleasing, and usually very inobvious.

But I would agree that using a general audio editor will usually produce
inaudible differences, especially if the final MP3 is at a high bitrate.
The LAME encoder which is free is probably the best at high bitrates, but
might have some high frequency ringing at low bitrates.

If it is for your pleasure and you can't tell the difference, great.  But if
it is for public performance you might wish to be very careful.  Others
might be able to hear the problems.  But the rule is that over 128kb the
differences are generally inaudible or at least not objectionable.  At that
rate and below some of the artifacts can sound nasty.  I have occasionally
run into cases where transcoding from one lossy format to another can
produce really obviously nasty rough sounding audio.

I am picky because I maintain a huge library of music for a dance group and
I want everyone to hear the music as the best possible.  I also can hear the
difference between regular FM and HD, but only by extremely careful A/B
comparisons.  The HD does have the advantage of greater immunity to certain
types of interference, and the extra channels.

John M. Clement
Houston, TX

> All of this is true, however, I can tell you from a LOT of 
> experience that unless have some seriously golden ears, there 
> will be no audible artifacts.  As far as how to do it, any 
> audio editing program can handle this simple task.  I use 
> Amadeus Pro (for the Mac, written by Martin Hairer, a 
> mathematician at the University of Warwick) and heartily 
> recommend it although there are many other alternatives for 
> Mac and other platforms.
>
> Ludwik, If you don't have the capability and don't care to 
> get into it, I'd be happy to do the concatenation for you.