40 MA XIMUMPC JANUARY 2006 JANUARY 2006 MA XIMUMPC 41
With the possible exception of the USB
Key that survived a washing and drying
cycle, no other Maximum PC Challenge has
ever surprised us as much as this one. It’s
downright humiliating, in fact, that in many
cases, we were unable to tell the difference
between an uncompressed track and one
encoded at 160Kb/s, the bit rate most of usconsidered the absolute minimum accept-
able for even portable players.
Some follow-up testing confi rmed our
suspicions: variable bit rate encoding makes
a tremendous difference in the audio quality
results, certainly enough to justify—many
times over—the slight fi le size increase.
Capping the bit rate at 160Kb/s in MP3 fi lescan be pretty harsh on a track, but allowing
the bit rate to wander upwards during more
complex passages—as variable bit rate
encoding does—and throttle down during
quieter sections captures an astonishing
amount of complexity while keeping fi le
sizes down to an impressive minimum.THE UPSHOT
(^) SCORE CARD
PLURALIST’S CURMUDGEON’S HIPSTER’S AUDIOPHILE’S
TRACK TRACK TRACK TRACK
PLURALIST’TRACK S CURMUDGETRACK ON’S HIPSTER’S TRACK AUDIOPHILE’STRACK
“Now, wait... is this fair?
Has this been done
correctly?”
“I thought this would be a
piece of cake.”
UNCOMPRESSED ✔ X X ✔
320K VBR ✔ X ✔ X
160K VBR ✔ X X X
UNCOMPRESSED ✔ X ✔ X
320K VBR X X ✔ ✔
160K VBR X X ✔ X
THE CURMUDGEON
Although ostensibly objective and cool-headed, the curmudgeon
was none too happy once the listening tests began. He was
initially grumpy, and as the minutes fl ew by, he became increas-
ingly restless and even hostile at times. He wanted to know, for
example, how the test administrator knew that the fi les were done
correctly if only the staff member who labeled the tracks knew
which was which.
Nonetheless, he marched forward, and was particularly
demanding of A/B testing, comparing por-
tions of his own track with numerous repeats.
Apparently, the diligence didn’t pay off: The
curmudgeon was unable to correctly identify
the quality level of any of the three versions of
his own track! In an eerie coincidence, however, he dissed the
Hipster’s track much as she dismissed his (“I thought Ani DiFranco
got all her anger out already....”), yet correctly identifi ed the quality
levels of the three versions of that track. He was also able to iden-
tify a 320Kb/s version and an uncompressed version of the other
track sets, but that’s all, for a modest total of fi ve out of 12 correct.
When the test results were revealed, the curmudgeon threw
a hissy fi t, questioning our methodology
before sinking into an oppressive
quiet behind his keyboard.
(^) THE AUDIOPHILE
We all thought it would be a piece of cake, for
that matter. With the fi nest consumer-
level soundcard, ace headphones,
and tracks we knew by heart,
who would have thought that
identifying a compressed audio
track could be so diffi cult? No
one was more surprised than the
audiophile. Like all the other par-
ticipants, there was a lot of leaning
forward, as if getting closer to the PC might expose some hidden
fl aw in the audio stream. Near the end of the tests, the Audiophile
remarked, “I specifi cally chose this song because I thought it
would be easy [to identify the compressed version]. It wasn’t.”
That’s pretty much the story told by his results—he was able
to identify the uncompressed version of his own track after
considerable A/B comparisons with the compressed ver-
sions, but mixed up the 320Kb/s and 160Kb/s versions.
He was also able to correctly identify the quality levels
of another participant’s track, and the 320Kb/s version
of yet another’s track, but had to settle on a tie with the
Curmudgeon, at fi ve out of 12.
SCORE CARD