Recording - March 2017 - 50

REVISITED

Ultrasone
PRO 900i

Soundstaging unlike anything else in a
pro studio headphone | Review by Mike Metlay
Ultrasone is a German company founded in 1991, whose headphones made
a big splash in the pro audio world when they were widely introduced in the
USA in the early 2000s. I was one of those reviewers who got splashed, back

in our July 2003 issue, and I've been following Ultrasone ever since, as the
company has expanded into multiple product lines-from audiophile and DJ
models to in-ear monitors.
It's been way too long since we've reviewed an Ultrasone headphone, and
in this review of the PRO 900i, we'll review what makes Ultrasone's
designs so unusual before delving into the product itself.
The PRO 900i is a slightly updated version of the PRO 900, which I
reviewed in our April 2009 issue. I don't mind updating that review with a
new listen... not when headphones sound as good as these.

So what's the big deal?
Ultrasone headphones have a patented design that differentiates
them from other headphones in a very simple way: the driver is
aimed, not down the ear canal, but at the temple just in front of and
below the ear. The reason for this is straightforward: a lot of the
spatial cueing and three-dimensionality of our listening experience
comes well before sound even enters the ear canal.
Sounds we hear are altered slightly as they reflect off of the pinnae,
the fleshy parts of the outer ear, and we instinctively use this sound
shaping to determine proximity and direction of sound sources. That's
how we can triangulate on where a sound is coming from by turning
our heads slightly, for example. Ultrasone's S-Logic design aims the
drivers' sound at a place where it can be processed by the pinnae
before hitting the eardrums, and the result of this simple tweak is a
soundstage that can only be described as otherworldly. I'll talk more
about this below.
Ultrasone headphones have a lot of nice features to them, from
the mundane (earcups that can fold flat, a good variety of accessories)
to the exotic (Mu-Metal shielding to prevent exposing the brain to
magnetic fields from the driver voice coils-an effect which has
never been conclusively proven to do any damage, but Ultrasone's
not taking any chances). But it's S-Logic, or in this case the refined
S-Logic PLUS, that really makes them stand out.
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RECORDING MARCH 2017

The PRO 900i
The PRO 900i is an S-Logic PLUS headphone with
40 mm drivers made from titanium-coated Mylar with
Neodymium/Iron/Boron magnets. Ultrasone quotes a frequency response (without tolerances) of 6 Hz to 42 kHz,
an impressively broad range well-suited to high-resolution
audio. The headphones weigh a very light 295 grams
and are quite comfortable, with easily-replaceable circular
earpads and a generously padded headband.
The headphones come in a semirigid plastic zipper case
with a spare pair of earpads and two cables: one 3-meter
coiled/straight cable with a 1/4" plug and one 1.5-meter
straight cable with a miniplug. Both feature gold-plated
connectors and screw into the left earcup of the phones.

Sound and staging
At the risk of repeating myself from seven years ago,
the unique beauty of Ultrasone headphones' soundstaging
is also the one area where users in pro audio need to
exercise caution. Headphones have a lot of uses in the
studio-they can be used for detailed listening while
editing and mixing tracks, they can be used as confidence
monitors for tracking in iso booths, and they can be used
as check monitors for completed mixes. My opinion of
Ultrasone phones remains the same as it's always been:
they're very risky headphones to use for checking mixes,
because nothing else, and I do mean nothing else, sounds
like them. If you mix specifically for Ultrasones, your stereo
image simply will not translate accurately to anything
else, and mixes created for other headphones or speakers
will be nearly unrecognizable on Ultrasones.
This is because the S-Logic PLUS drivers in the PRO
900i create an extraordinarily deep, wide, and immersive
soundstage that envelops your head and creates sound
localizations that might not have anything to do with
how the original mix sounded (unless it was created
on Ultrasones, I suppose). Ultrasone calls it "Natural

Table of Contents for the Digital Edition of Recording - March 2017