W
ith all the legitimate warnings about hearing damage induced by in-ear
headphones, you might think a portable headphone amp is the last thing
on-the-go music listeners need. But that’s not going to stop us from praising
this tiny doodad from an equally tiny division of Asus.
Don’t get us wrong: Listening to music played at high sound-pressure lev-
els will absolutely damage your hearing over time. But it’s also true that many
people are dissatisfi ed with the volume levels they achieve with high-quality
earbuds and headphones. The reason is twofold: First, most MP3 players are
equipped with relatively low-powered amps in order to conserve battery life.
Second, high-quality earbuds and headphones have relatively high impedance.
Crank up the underpowered amp to overcome the high impedance and you get
distortion and possible ear damage.
When you pair good headphones with a good amp, you don’t need to blast
your eardrums to smithereens to achieve a satisfying listening experience, and
that’s where the lithium-polymer Mobile Amp comes in.
The amp’s house is primarily made of plastic, but the oversize volume
control is machined aluminum and feels exquisite when rolled between the
thumb and forefinger. A system of detents, on the other hand, would prevent
the volume from changing while the device is jammed in your pocket. We
also wish Asus had designed the amp with an input jack instead of the fixed
cable, which is too short to reach a PC’s soundcard jacks (18 inches is too
short for even front-mounted jacks). And we were disappointed with the
cheap sliding power switch on the bottom of the amp. And a power-on LED
would have been welcomed.
But these complaints melted away when we plugged in our UltrasoneProLine 750 headphones (40-ohm impedance), switched on the amp, and heard
the sizzling electric sitar on Paul Thorn’s gospel-infused “Sister Ruby’s House of
Prayer.” We were just as happy listening with Shure’s E4g earphones (29-ohm
impedance). With a maximum output of 70 milliwatts, this sucker gets loud! But
we didn’t need to listen at high volume to get a highly satisfying listen-
ing experience.
—MICHAEL BROWNiAsus Concepts Mobile Amp
Asus wants to get inside your head
76 MAXIMUMPC JUNE 2007
reviewsTESTED. REVIEWED. VERDICTIZED
8
iASUS MOBILE AMP
$65, http://www.iasus-concepts.comLoop a lanyard through iAsus Concepts’s Mobile Amp and you
can lash it to your MP3 player. The device has plenty of power
to drive two sets of headphones using the included splitter.1.4
"2 "I
f you dig your MP3 player but can’t stand jammin’ earbuds into your head
to listen to it, you’ll find yourself attracted to Razer’s Pro-Tone m250
headphones. But after using them, you might resign yourself to suffering
with the buds.
Headphones are a highly personal choice, and some people may be
put off by the m250’s unusual design. A rubber-coated arm hooks over your
outer ear—much like a pair of eyeglasses—and the disk-like driver folds
over to rest on top of your ear. The fit was snug but comfortable, and the
m250s remained in place through a series of jumping jacks and touch-your-
toe exercises (well, as close as we could get to our toes, anyway). The clip
design might cause a problem for those who wear eyeglasses, but we didn’t
perceive any difference in sound with or without our own cheaters.
After catching our breath, however, we concluded that our dissatis-
faction with the way the m250s sound is related to the distance between
their speaker elements and our eardrums. Fast-moving high-frequency
sound waves travel far; slow-moving low-frequency sound waves don’t.
When we cranked up our iPod in search of the wandering bass line in John
Hiatt’s “Woman Sawed in Half,” we absolutely cringed when the yah-yah-
yah chorus burst in. Harsh highs weren’t as much of a problem with some
of the other songs we tested with, but our craving for bass was never sat-
isfied. Razer’s ProBass technology does produce a lot of bass, but the only
way it made it down our ear canals was when we pressed the m250s snugagainst our ears.
The m250s also leak like a sieve: Listening at even moderate volume
creates a tinny concert hall in miniature for everyone within a six-foot
radius of your head. And as you might have guessed, these headphones do
nothing to isolate your ears from outside noise. But this didn’t stop Razer
from tucking an airline headphone adapter into the nicely appoint-
ed, zippered nylon clutch.
—MICHAEL BROWNRazer Pro-Tone m250
But they look so cool!
6
RAZER PRO-TONE M250
$50, http://www.razerzone.comRazer’s Pro-Tone m250s are both figurative and literal light-
weights, tipping the scales at just 1.38 ounces.