MaximumPC 2007 09

MAXIMUMPC

CHALLENGE

ANOTHER

Can you hear the difference between AAC songs encoded

at 128Kb/s bitrates and those encoded at 256Kb/s?

T

he fi rst cracks in the record industry’s mind-numbingly

dumb position that commercial music must be encum-

bered with soul-sucking digital rights management

technology have begun to appear: Apple—in partnership with

EMI—is hawking DRM-free music at twice the bitrate of its

standard fare (256Kb/s vs. 128Kb/s) and charging a $0.30-

per-track premium. We’re all for DRM-free music, but 256Kb/s

still seems like a pretty low bitrate—especially when you’re

using a lossy codec.

So we decided to test a random sample of our col-

leagues to see if they could detect any audible difference

between a song ripped from a CD and encoded in Apple’s

lossy AAC format at 128Kb/s and the same song ripped

and encoded in lossy AAC at 256Kb/s. Does the higher

bitrate deliver additional value, or is the added cost justi-

fi ed solely by the absence of DRM?

We hypothesized that no one would be able to discern

the difference using the inexpensive earbuds (MSRP: $30)

that Apple provides with its product, so we also acquired

a set of high-end Shure SE420 earphones (MSRP: $400).

We were confi dent that the better headphones would

make the task much easier, since they would reveal more

fl aws in the songs encoded at lower bitrates.

—BY MICHAEL BROWN

50 MAXIMUMPC SEPTEMBER 2007

THE

DOUBLE-BLIND

MUSIC-LISTENING

TEST