Newbie question, mp3 quality
 

In message , Arny Krueger
writes
"Don Pearce" wrote in message

On Sun, 23 Oct 2005 19:43:31 +0100, Chris Morriss wrote:


The places where I hear the significant differences are
where there's a single clearly recorded female solo
vocal which also has a high-amplitude low-bass note at
the same time. The vocal gets very degraded when the
bass note is present, although listening on the
Sennheiser HD580s to the original CD, there is no
degradation of the vocal during the bass note. It's
almost like an intermodulation effect. It's not
perceivable (to me)) in complex music or in orchestral
music, probably due to the significant masking that this
provides, the small-scale female folk-ish material I
like seems to be the easiest to notice the effect on.

Well, that most certainly isn't a normal MP3 artifact -
it just doesn't do that. So I don't know exactly what is
going on for you, but I would suggest you find yourself
an alternative MP3 codec; there are plenty out there.


Sounds like clipping in the headphone amp - tubed? ;-)


Hello Arny.

No, not a tubed headphone amp, although it's exactly that sort of
effect!

I've been monitoring the output from an M-audio Transit USB sound card.
I've not tried other codecs yet, but so far it's still the case that
192k MP3 is worse than the ATRAC-SP output from my (full size) Minidisc
deck. I've tried a comparison with the Ogg codec in Freerip and that
seems to be a fair bit better.

When I get another codec loaded on the pc I'll give it a better
comparison.

Just for info, (though I doubt if anyone else here has the CD), the
track the effect is most noticeable on is 'Euchari' by the Swedish band
'Garmarna'
--
Chris Morriss

Newbie question, mp3 quality
 

In message , Arny Krueger
writes
"Don Pearce" wrote in message

On Mon, 24 Oct 2005 09:15:48 +0100, tony sayer wrote:

The places where I hear the significant differences are
where there's a single clearly recorded female solo
vocal which also has a high-amplitude low-bass note at
the same time. The vocal gets very degraded when the
bass note is present, although listening on the
Sennheiser HD580s to the original CD, there is no
degradation of the vocal during the bass note. It's
almost like an intermodulation effect. It's not
perceivable (to me)) in complex music or in orchestral
music, probably due to the significant masking that
this provides, the small-scale female folk-ish material
I like seems to be the easiest to notice the effect on.

I can't see, or hear!, how any system that throws info
away can be totally transparent unless it can code the
original info in the same space....

Then you probably need to do some reading.

Agreed. The fact that MP3 works at all is proof that masking
is a very powerful effect.

The irony of audiophools doing so much listening via
perceptual coders should not be lost on us of the more
rational persuasion.

They seem to still claim to hear that which can not be
measured, but now they are not hearing the loss of that
which can be clearly measured.

Note:

http://www.dedicatedaudio.com/inc/sdetail/4345?noc=true


I don't have any problem separating an MP3 from a Wave file using my
measuring kit. Even with a simple 1/24th octave pink noise analysis.
It's my ears that can't tell the difference. They certainly need a
visit to the gold-platers!
--
Chris Morriss

Newbie question, mp3 quality
 

Have any of you pro-mp3 bods got a cd with a swept frequency tone on it ?
rip that to an mp3 and then play it back, the higher frequency end of the
sweep will be a dead giveaway ( anti-aliasing ? ). NB same happens on
portable cd players playing a cd eg Sony CDman ( which you'd think was a
good make ) because of the antijog feature the cd is spun faster than normal
and sampled into a buffer to give the laser time to recover if it gets
knocked, play a cd with a swept tone with/without the jog protection the
differance is amazing................

Pete