Definitive Technology IWSub IWSub 10-10 User manual

“beyond amazing”
HOT
new
system
review
UIW RLS II &
IWSub Reference
DEFINITIVE TECHNOLOGY’S

y first draft of the intro for this
review was rather witty, if I do say
so myself. It lamented the fact that
because so many of today’s in-wall speakers
are so good, it’s difficult to write something
interesting about them. But I composed those
opening paragraphs before I had actually
listened to the speakers. Much as I hate to
throw away a perfectly good intro, it would
no longer do — because it was no longer true.
One could not consider Definitive
Technology’s UIW RLS II in-wall speaker
and IWSub Reference in-wall subwoofer to
be ordinary products, even at first glance.
Take the UIW RLS II’s pair of passive radia-
tors, which Definitive added to fix one of the
biggest problems with high-quality in-walls:
lack of bass. Like most high-end in-walls, the
UIW RLS II has an integral enclosure, or
back box. A back box improves fidelity
because it keeps sound from the back of the
woofer from entering the wall cavity, and thus
keeps the wall from vibrating and producing
its own sound. However, pressure that builds
up inside the back box restricts the woofer
and diminishes deep bass response. But using
passive radiators relieves this pressure and
uses it to produce even more bass.
Also, the UIW RLS II’s slim front baffle
increases mounting flexibility. Many in-walls
are wide, so your installer can move them
only an inch or two to either side before hit-
ting a stud. With the UIW RLS II, though,
your installer can move the speaker several
inches to the left or right. This characteristic
is particularly important if the speakers are
mounted behind a perforated screen. With
smaller screens, it can be tough to cram left,
center, and right speakers behind the screen
without having to move a stud or two.
The IWSub Reference in-wall sub is even
more unusual. Subwoofers are the final fron-
tier of in-wall speaker engineering because
few good woofers are slim enough to fit into
a standard 3.5-inch-deep wall. Plus, sub-
woofers demand a back box to perform well,
and the back box takes up even more space.
Definitive is among the first manufacturers
who have risen to this engineering challenge.
NEW REVIEWS
“it’s really beyond amazing”
SECOND DRAFT
Definitive Technology’s UIW RLS II and IWSub Reference
surrender enough surprises to make a lazy editor rewrite his review.
M
BY BRENT BUTTERWORTH
“I can think of no other
in-wall speaker system
that matches this one’s
versatility, sound quality,
and value”
Cover photo: Clockwise from far left: the UIW RLS II
with its grille on, the IWSub Reference with its grille off,
and the SubAmp 600.
“the system wraps me in a
huge ambient soundstage”

The IWSub Reference
employs a 13-inch woofer
that has been radically
slimmed to fit in a wall;
it’s such a tight fit that
Definitive had
to cut a hole in the
back of the enclosure
to accommodate the
woofer’s magnet. A 13-
inch passive radiator
reinforces the woofer’s
deepest bass notes.
A separate amplifier,
the SubAmp 600, fits
into your equipment
rack. The SubAmp 600
is a stereo amp; it pro-
vides 275 watts to a sin-
gle IWSub Reference or
230 watts each to two
IWSub References.
Does the UIW RLS II
sound as good as many
excellent in-walls already
on the market? Actually,
it sounds better than
most. If this speaker has
a flaw, I cannot find it.
(OK, the product name
sucks. But besides that.)
It sounds at least as good
as any other in-wall I
have tested, and given
that I started evaluating
these speakers regularly
in 1995, I have tested
quite a few. From the
bass to the high treble,
it sounds as uncolored as
any speaker that comes
to mind. I hear pinpoint
imaging between the
speakers, and the system
wraps me in a huge
ambient soundstage.
The UIW RLS II does
not match the soundstag-
ing of the best freestand-
ing speakers, but it comes
close — and it is far bet-
ter in this regard than
practically any current
in-wall speaker except for
the MartinLogan Voyage
and Thiel PowerPlane.
NEW REVIEWS
“is far better in
this regard
than practically
any current in-
wall speaker”
The IWSub Reference (below)
uses an active 13-inch woofer
on top and a passive radiator
below. In order to maintain
rigidity in the woofer’s shallow
cone, Definitive made it from
stiff, thick treated paper; it feels
almost like a thin sheet of MDF.
“The IWSub
Reference is
certainly the
best in-wall sub
I have heard”
The two 6.5-inch passive
radiators used in the UIW
RLS II (right) are like
speaker without magnets or
voice coils. They reinforce
the speaker’s bass and
negate the downside of
using a back box.

The UIW RLS II also
plays incredibly loud; I
would recommend it for
all but the largest home
theaters. It produces
enough bass that you
can use it without a sub-
woofer in a smaller room.
The only problem with
the UIW RLS II is that I
never want to stop listen-
ing to it; what I plan as
hour-long evaluative ses-
sions end up stretching
well past my bedtime.
The IWSub Reference
is certainly the best
in-wall sub I have heard,
even if it doesn’t reach
the same level of perfec-
tion as the UIW RLS II.
It produces a surprisingly
full sound, even in my
large home theater. And
the sound is well-defined,
too — the bass lines of
my favorite rock CDs
come through precisely,
never boomy or bloated.
The best freestanding
subs sound a little
punchier and can surpass
the IWSub’s bass output,
but the sacrifice you get
by going in-wall is in this
case minimal.
On top of all this,
both speakers areeasy
to install. Everything
considered, I can think of
no other in-wall speaker
system that matches this
one’sversatility, sound
quality, and value. I was
going to call it amazing,
but given that Definitive
accomplished this fidelity
with such straightforward
engineering and at such
an affordable price, it’s
really beyond amazing.
■DESCRIPTION
In-wall speaker system for home theater
or stereo. Subwoofer employs separate
275-watt amplifier.
■COMPONENTS
UIW RLS II: two 6.5-inch polypropy-
lene cone woofers, two 6.5-inch passive
radiators, one 1-inch aluminum dome
tweeter.
IWSub Reference: 13-inch treated
paper cone woofer and 13-inch passive
radiator
■CONNECTIONS
UIW RLS II: spring-loaded binding
posts, accepts bare wire, pins, or
banana plugs
IWSub Reference: same as above
SubAmp600: line-level inputs for left,
right and LFE channels; dual five-way
metal binding posts for subwoofer out,
main speaker in, and main speaker out
■DIMENSIONS
UIW RLS II: 29.8 x 8.2 inches (hw),
3.5-inch installed depth
IWSub Reference: 26.2 x 15.5 inch-
es (hw), 3.5-inch installed depth
SubAmp600: 3.7 x 17.1x 9.6 inches
(hwd)
■PRICE/CONTACT
PRICE: UIW RLS II $650 each, IWSub
Reference $999 each, SubAmp600
$599
CONTACT definitivetech.com,
410.363.7148
11433 Cronridge Dr. • Owings Mills, MD 21117 • [phone]
Visit us at www.definitivetech.com
From HOME ENTERTAINMENT magazine, MAY/JUNE 2006.
NEW REVIEWS
“it sounds as
uncolored as
any speaker”
“Ihear pinpoint
imaging
between the
speakers”
The UIW RLS II (shown above
with side view) has an installed
depth of only 3.5-inches.
HE
“Inever want
to stop listening
to it”