Snell XA 55cr User manual

XA90ps
XA75ps
XA55cr
Owner’s Manual

SPECIFICATIONS 3
PRODUCT DESCRIPTION 4
SERIES FEATURES 6
PLACEMENT OF YOUR SPEAKER SYSTEM 8
CONNECTING THE SPEAKERS 10
MULTICHANNEL SYSTEMS 12
OPTIMIZING THE SOUND 14
SPECIAL FEATURES 17
LISTENING LEVELS AND POWER-HANDLING 18
HOW TO CARE FOR YOUR SPEAKERS 18
SAFETY INSTRUCTIONS 19
LIMITED WARRANTY Back Cover
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TABLE OF CONTENTS

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XA 90ps XA 75ps XA 55cr
Frequency Response (±3dB) 32–22,000Hz 34–22,000Hz 55–22,000Hz
Nominal Impedance 4 ohms 8 ohms 4 ohms
Recommended Amplifier Power 100–300 watts 75–300 watts 50–300 watts
Sensitivity [2.83v at 1m (1 watt)] 90dB 88dB 88dB
Driver Complement
(all video-shielded)
Front Tweeter 1" (25mm) black anodized 1" (25mm) black anodized 1" (25mm) black anodized
aluminum, separate PVC aluminum, separate PVC aluminum, separate PVC
surround surround surround
Midranges 2 x 2.5" (60mm) 2 x 2.5" (60mm) 2 x 2.5" (60mm)
Woofers 2 x 6.5" (160mm) 1 x 6.5" (160mm) 2 x 6.5" (160mm)
Distortion-reducing Distortion-reducing Distortion-reducing
magnetic circuit magnetic circuit magnetic circuit
Subwoofer(s) 2 x 10" (250mm) 1 x 10" (250mm) none
Dual spider, heatsink Dual spider, heatsink
Rear Tweeter 1" (25mm) 1" (25mm) none
Subwoofer Amplifier 300 watts 200 watts none
Controls Parametric bass EQ, Bass level, LFE level, treble Treble level, boundary
bass level, LFE level, level, boundary compensation, compensation
treble level, boundary rear tweeter
compensation, rear tweeter
Cabinet Construction Heavily braced, veneered Heavily braced, veneered Heavily braced, veneered
MDF 3⁄4"minimum MDF 3⁄4" minimum MDF 3⁄4" minimum
Baffle Construction Rubber isolated: constrained Rubber isolated: constrained Rubber isolated: constrained
layer damping, low diffraction layer damping, low diffraction layer damping, low diffraction
radius radius radius
Grille Frameless perforated metal Frameless perforated metal Frameless perforated metal
over 51% open area over 51% open area over 51% open area
Maximum Dimensions (HxWxD) 54.5 x 11 x 19.5" 46 x 11 x 19.5" 9 x 22.5 x 11"
(138 x 28 x 50cm) (117 x 28 x 50cm) (23 x 57 x 28cm)
Weight, Net 125lbs (57kg) 100lbs (45kg) 39lbs (18kg)
Shipping Weight 198lbs (90kg) 166lbs (76kg) 44lbs (20kg)
Finishes Black Oak, Cherry, others Black Oak, Cherry, others Black Oak, Cherry, others
to special order to special order to special order
SPECIFICATIONS

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The XA Series of products is an “ultra” high-performance speaker
line utilizing a unique expanding array format (XA). This array
was created after several months of intensive computer model-
ing and study, with a serious review of what is appropriate for
both music and home theater usage. With the new XA Towers,
Snell engineers have created a five-element array with virtually
no change in response through ±15 degrees vertically, yet a
desirable, significant drop in response at 30 to 45 degrees above
or below axis. There is virtually no variation within a likely listen-
ing window, but a significant reduction in energy of the floor
and ceiling bounce...which creates a reduced reverberant field for
a clearer, more articulate sound. This design approach is not only
beneficial to the movie lover, but is also much more appropriate
for multichannel music listening with the latest discrete music
formats.
All XA products feature a high degree of “environment tunabili-
ty” with boundary switches, treble switches, subwoofer level and
rolloff adjustments (XA Towers), and even a parametric equalizer
(XA 90ps). They are all magnetically shielded for use near video
monitors.
The XA products also feature stunning styling that is fully
integrated with their acoustical function.
XA 90ps
High-performance floor-standing system
Sophisticated five-element expanding source array XA controls
directivity down to 100Hz. Twin 10-inch (250mm) powered
subwoofer with 300-watt amplifier. The amplifier includes a
parametric equalizer for the ultimate in environment tunability.
Remote control offers low- and high-frequency adjustment
to optimize for all programs. The driver complement includes a
1-inch (25mm) black anodized aluminum-dome tweeter, flanked
by a pair of 21⁄2-inch (60mm) upper midranges; a pair of 61⁄2-
inch (150mm) lower midranges further surrounds the central
cluster. A soft-dome rear-firing tweeter is included for added
ambiance. Below 100Hz, a pair of 10-inch (250mm) bass units
provides bass to 32Hz (-3dB). The unique styling allows the
use of front-firing 10-inch (250mm) woofers with a slim cabinet
and a low diffraction baffle.
PRODUCT DESCRIPTION

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XA 75ps
High-performance floor-standing system
Special three-element XA for controlled directivity to 400Hz. 10-
inch (250mm) powered subwoofer with level and corner shape
switches for room and program optimization. The driver comple-
ment includes a 1-inch (25mm) black anodized aluminum-dome
tweeter, flanked by a pair of 21⁄2-inch (60mm) upper midranges
and a 61⁄2-inch (150mm) lower midrange beneath the XA cluster.
A soft-dome rear-firing tweeter is included for added ambiance.
Below 100Hz, a 10-inch (250mm) bass unit and a 200-watt
amplifier provide bass to 34Hz (-3dB).
XA 55cr
Full-range music- and movie-quality center channel
The XA 55cr center channel is tuned to precisely match the tonal
balance of the XA Towers for seamless five-channel movie or
music reproduction. It shares an identical three-element XA to
the above two models. This three-way design uses a 1-inch
(25mm) black anodized aluminum-dome tweeter surrounded by
two 21⁄2-inch (60mm) midrange units. The array is flanked by left
and right 61⁄2-inch (150mm) bass units in a sealed enclosure.
Bass extension is to 50Hz. Video shielding, a placement switch,
and smooth off-axis frequency response allow placement above
or below a TV or in a cabinet.

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XA SERIES FEATURES
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Multielement Expanding Array
Months of study and computer simulation resulted in a sci-
entifically designed five-element array with idealized disper-
sion characteristics (three-element in XA 75ps and XA 55cr).
The XA’s performance is seamless and invariant within any
likely listening position. Controlled directivity beyond normal
vertical angles reduces room involvement, for a clearer and
more detailed image with either movie or multichannel
music sources.
Integral Powered Subwoofer
An integral subwoofer gives the low-frequency foundation
necessary for music or cinema reproduction (XA Towers).
Inclusion of an amplified subwoofer allows the upper-range
drivers to be optimized for higher sensitivity.
Controls for Subwoofer Optimization
Controls on the dedicated subwoofer amplifier allow
optimization of subwoofer performance to both the room
and program. Parametric Equalization (XA 90ps only) allows
correction of room acoustic flaws. Bass level and subwoofer
rolloff shape controls (via remote in the XA 90ps, via rear
panel in the XA 75ps) allow for adjustment as needed for
program material, room, and taste.
Platform Baffle
This three-layer sandwich isolates the baffle from the cabi-
net to decrease panel resonances and coloration—especially
in the critical midrange. The Platform Baffle consists of
materials of varying density—an extremely dense outer layer
to which the tweeter and bass units are mounted, a
“squishy” neoprene middle layer, and a medium-density
inner layer that attaches to the cabinet.
Radiused-Edge Baffle
The elliptical radius on our baffle edge reduces re-radiation
for a cleaner and smoother response—especially off-axis.
Snell pioneered this technique in the original Type A speaker
system in 1976.
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Heat Sink/Terminal Plate
Heat-producing crossover components are mounted to a die-
cast aluminum heat sink for stable, consistent performance
at high power. This large heat sink also draws heat from
inside the cabinet, keeping critical driver components cooler.
The terminal plate has two sets of five-way gold-plated
binding posts for bi-wiring or bi-amplifying.
Rear-Firing Tweeter
The rear-firing tweeter on the XATower models adds neces-
sary high-end “fill” to the soundstage, creating a broader,
deeper stereo image when the speaker is placed away from
a back wall. An on/off switch allows you to defeat the rear
tweeter when placed up against a back wall.
Grille Design
The custom-perforated metal grille has no frame to cause
degrading reflections in the upper frequencies. Rubber
mounts isolate the grille posts from the Platform Baffle.
Hand-Tuned Crossover
These networks adhere to an “in-phase” or Linkwitz Reilly
design. (Time alignment and coherency are achieved through
the transition region from driver to driver.) In production,
each crossover is individually tuned by our technicians to
within ±0.5dB of the master reference, assuring an identical
sound balance to our master reference system.
Handmade Cabinets
Our cabinet department hand assembles each cabinet, and
then hand sands each several times. Multiple coats of hand-
applied finishing oils reveal great depth to the wood grain.
The result is a cabinet of exceptional workmanship, with
sharp corners, smooth sides, and natural beauty.
Veneers
We use premium, book-matched veneers in our oiled cabinets,
chosen for grain consistency and aesthetics. A pair of speak-
ers uses wood veneer from the same tree, so grain patterns
are consistent. Our cabinet shop sequences the veneer, main-
taining a match for the top, right/right, and left/left sides
of each pair of speakers. We even go so far as to veneer the
inside of the cabinet. This way, as the cabinet undergoes
changes in humidity in your home, it won’t warp or come
apart at the edges.
Placement Switch
This switch “normalizes” the speaker if it is placed in a cabi-
net or next to a large object, like a big-screen TV. This Snell
feature assures the proper balance of your speaker in less
than ideal placements.
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PLACEMENT OF YOUR SPEAKER SYSTEM
of any of them. Moving your listening position may affect the
sound as much as moving the speakers. If practical, try different
listening locations as well as speaker locations. Bass level con-
trols (XA 75ps) will allow you to help improve the bass balance at
whatever final location you choose. Additionally, the parametric
equalizer of the XA 90ps will allow you to electronically correct
one major bass aberration per speaker, thus making placement
even less critical. (See ”Optimizing the Sound” section).
Boundary Effects
Large surfaces near your speakers will affect the level of upper-
bass and lower-midrange frequencies. This can make voices
sound unnatural. A feature to counteract this is the ”Bass
Loading” switch, with positions for ”Normal” or ”Boundary.”
Refer to the switch on the input terminal plate.
Normal or Freestanding placement refers to a situation in which
the XA Tower has at least a 12-inch (30cm) clearance on all four
sides.
¤Away from large furniture
¤Not close to walls
¤Set Boundary switch to Freestanding
Boundary placement refers to a situation in which the XA Tower
is bounded on at least one side by a large object.
Set Boundary switch to Boundary if:
¤Placed beside a TV
¤Placed beside a bookshelf or an audio/video
cabinet
¤Placed next to a wall
See the section entitled “Optimizing the Sound” for more on
adjustments related to these placements.
XA Towers
The XA Towers are designed for either freestanding or boundary
placement.
Stereo Image
The distance between the speakers determines the width of the
stereo image. If the speakers are placed too close together, the
image will be too narrow; too far apart and the blend will suffer,
creating a hole in the middle. When properly placed, your speak-
ers will create a continuum of “virtual images” from left to right,
with an illusion of sound outside, in front, and behind the
speaker systems.
¤We recommend an angular separation between 45° and 60°
(when viewed from above).
This is equivalent to a separation between the speaker systems
that is about 85% of the distance to either of the speakers.
Creation of sounds between the speakers requires some precise
placement. The distance from the left speaker, right speaker, and
center channel to the listener location should all be as equal as
possible. We advise using a tape measure to equalize these two
distances to the primary listening position. The payoff will be
well worth the time and effort.
Room-Related Bass Effects
Experiment until you find the best overall sound for your room.
Choose a source with a heavy and continuous bass line, repeat a
short section until you have a firm impression of it in your mind,
and then try another speaker location. Repeat this process until
you are content with the bass response you are getting. Aim for
even reproduction of each bass note without undue prominence
45°to 60°
Distance Between Speakers
Distance to Listening Area
Freestanding Boundary

The XA 55cr can compensate for either TV top or cabinet place-
ment. Refer to the switch on the input terminal plate. This is
achieved by the right switch, on the input terminal plate.
Normal refers to a situation in which the XA 55cr is:
¤On top of a 30-inch (76cm) or smaller TV, and the TV is free-
standing in your room
¤Stand mounted away from boundaries
(If in doubt, use whichever position makes voices sound more
natural.)
Boundary placement refers to a situation in which the XA 55cr is:
¤ On top of a TV larger than 30 inches (76cm)
¤ On top of a TV that is placed in an audio/video cabinet
¤ Below a TV or on a shelf
(If in doubt, use whichever position makes voices sound more
natural.)
Center channel—Setting the Placement Switch
¤ TV top placement: Set the Placement Switch to NORMAL.
¤ Voices sound ”thin”: Set the Placement Switch to NORMAL.
¤ Cabinet placement: Set the Placement Switch to BOUNDARY.
¤ Voices sound ”thick” or ”heavy”: Set the Placement Switch
to BOUNDARY.
Attaching the Bumpers
Four rubber bumpers are included with the XA 55cr. Stick them
to the bottom of the speaker cabinet to protect the finish on
your TV.
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Toe In
Toe in refers to the angling of the speaker systems toward the
listening location. Toe in is a matter of taste. As the degree of
toe in increases, the stereo effect becomes more sharply defined,
becoming more like that of headphones. Toe in also improves
the stereo effect for off-center listeners. Having your speakers
aligned with their backs parallel to the wall gives a more spa-
cious sound with a less well-defined central image.
Toeing in should be the last step in the placement of your speak-
er system. After finalizing speaker position and listening location,
place the speakers with their backs parallel to the back wall or
cabinet. Experiment from there, turning the speaker by 10-inch
increments toward the listening area until you achieve the
desired effect.
Setting the Carpet Spikes
Four steel spikes (#5/16-18 thread) are included with the XA.
Use them to balance the speaker when placing the XA on carpet.
XA 55cr Center Channel
The center channel keeps musical or soundtrack information
centered in the listening area. Therefore, its placement relative
to the left and right speakers is critical.
Place the speaker on top of or beneath your TV with its front
edge as far forward as practical. Try to keep the front of the
speaker flush with the front of the screen.
When possible, place the height of the XA 55cr near the tweeter
height of the XA Towers (about 40 inches (1m) above the floor).
If you need to place the speaker significantly higher or lower,
angle it toward ear level.
Cabinet Placement
TV Top

CX or DX
amplifier or receiver
surround processor
speaker terminal
jumper straps
LFE
input
sub
out
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For All Models
Choosing Cable
We recommend minimum 16-gauge high-quality speaker cable
or thicker for runs up to 25 feet (8m) and 12-gauge wire or
thicker for longer runs. (We use a custom-configured 12-gauge
oxygen-free cable in our crossover networks.)
Connecting with Bare Wire
Insert bare wire into holes and tighten.
Connecting with Banana Plugs, Spade Lugs, or Pins
The binding posts accept standard banana plugs and pins, and
can accommodate 5/16" or larger spade lugs.
Warning! To prevent electrical shock, always switch off the
amplifier or receiver when making connections to the speaker
system.
Basic Connections
¤Keep the speaker terminal jumper straps in place.
¤When making connections, be sure to connect +to +(red)
and –to –(black).
Connecting the XA Towers
CONNECTING THE SPEAKERS
Connecting the XA 55cr
Connecting the XA 55cr to a Surround Processor
¤Select the ”small” or ”normal” setting on your receiver or
processor for the center channel. This routes all bass
information (typically below 120Hz) to the subwoofers of
the XA Towers.
¤When making connections, be sure to connect
+to +(red) and –to –(black).
Match the sound levels of each speaker.
¤Your home theater system most likely includes a test signal
that simplifies level matching. Refer to the instructions
provided with these electronics.
surround sound receiver or amplifier
left front center front right front
SC

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Using One Amplifier for Each Speaker
Make sure that the amplifiers are identical.
1. Unscrew both sets of terminals and remove the jumper straps.
2. Connect the cables from the bottom set of terminals to the
first amplifier’s right channel.
3. Connect the cables from the top set of terminals to the first
amplifier’s left channel.
4. Repeat steps 2 and 3 above for the second amplifier.
left speakerright speaker
right channel amplifier left channel amplifier
Bi-Wiring and Bi-Amping (All Models)
left speakerright speaker
low-frequency amplifier
high-frequency amplifier
Bi-Amplifying
Using one amplifier for the bass, and one for the high end:
1. Unscrew both sets of terminals and remove the jumper straps.
2. Connect the cables from the bottom set of terminals to the
low-frequency amplifier driving the bass units.
3. Connect the cables from the top set of terminals to the high-
frequency amplifier driving the tweeters.
4. Do not use an external crossover. It will interfere with the
phase and frequency response.
CX or DX
amplifier or receiver
Bi-Wiring
1. Use equal lengths of the appropriate wire when
bi-wiring each speaker. Consult your dealer for cable options.
2. Unscrew both sets of terminals and remove the jumper straps.

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MULTICHANNEL SYSTEMS
The growth of multichannel formats has greatly increased our
opportunity for realism and involvement in reproduced movies
and music. Unfortunately, it has also complicated system setup.
The next sections explain how to connect the Snell XA 90ps, XA
75ps, and XA 55cr in a multichannel system and how to configure
your surround processor. Note: We make assumptions about
your surround processor based on what is typical in the market.
Consult your processor’s manual for the specifics.
Usually, the XA Towers will be connected in the same way as a
normal full-range speaker. Although they contain a powered
subwoofer, full crossover is included, and an external crossover
is neither necessary nor desirable. In a two-channel system, they
will be connected as any other system, with the exception of the
need for a power connection to the tower’s subwoofer amplifier.
A stereo power amplifier or two monoblock amplifiers will feed
full-range signal to the multiway binding post inputs.
If used with a home theater system, the most probable configu-
ration will be that the left and right towers are larger than
center and surround speakers and therefore will have more bass
extension and bass power-handling. You will then want to use
the towers as the subwoofers for the other channels. Still, this
will be accomplished via the normal speaker-level inputs.
Most multichannel processors have setup options that designate
each channel’s loudspeaker to be “Large” or “Small.” When set to
“Small,” the bass for that channel will be sent to another chan-
nel that is designated “Large,” or perhaps to a subwoofer. Set
the processor so that the front left and front right channels are
”Large” and all other channels are “Small.” Generally, the bass
of the left surround will go to the left front channel, the bass
of the center channel will split equally between left and right
front, etc. This is the ideal configuration. One benefit is that you
will have stereo bass; whereas, with virtually all processors, any
system using a subwoofer will have mono bass.
Use with External Subwoofers
First, Should You?
Unless an external woofer has more surface area than the four
10-inch units contained within a pair of XA 90ps’s, or the twin
10-inch units within a pair of single XA 75ps’s, you are better off
not using it. It will reduce the output capability compared to the
alternative of sending all bass to the active towers.
If you already have a subwoofer 18-inches or larger, then it
might be worthwhile to use the subwoofer as an LFE-only chan-
nel. (See page 13 for discussion of ”LFE Input.”) The rest of the
system will be still be configured as above with the left front
and right front towers designated as “Large.”
¤Select the ”Large” setting on your receiver or processor for
your main speakers. This routes all bass information (typically
below 120Hz) to your XA Towers.
¤Select the ”Small” or ”Normal” setting on your receiver or
processor for your center and surround channels. This routes
all bass information (typically below 120Hz) to the XA Towers,
where it will be directed to the built-in subwoofers.
Match the sound levels of each speaker.
¤Your home theater system most likely includes a test signal
that simplifies level matching. Refer to the instructions
provided with these electronics.

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LFE Input
LFE (Low-Frequency Effects) refers to the “.1” channel of a “5.1”
channel recording. Normally, all signals will come to the active
towers via the normal speaker-level inputs. However, your Snell
XA Towers include an alternative line-level input for bass signal
connection. If your processor allows you to feed all five-channel
bass to the front left and right channels, and by so doing leaves
only the LFE (.1 channel) at the processor’s subwoofer output,
then a coaxial lead can be run to each tower’s LFE input.
To understand its use, a little background about multichannel
formats is in order. Dolby® AC-3 and other 5.1 systems are
configured as five full-frequency range channels and one addi-
tional bass-only channel dubbed the .1 channel. Since the five
channels are full range, there is no restriction of what type
of signals can go into each. Certainly, the bass frequencies of
the background music of a movie will be sent to each channel
in line with all other components of the musical mix.
Explosions and sound effects are another story. It evolved in
movie cinema practice that theater owners wanted a separation
of normal soundtrack material from explosions and effects.
This separate track became known as the LFE or Low Frequency
Effects channel (later the .1 channel). Theater owners could then
decide if they wanted to invest in large theater subwoofers. If
they decided not to invest, they knew that explosions and such
would not be overloading the main system because they were
on a separate channel that could be ignored.
In order to have adequate headroom for effects, Dolby specifies
that, after decoding and D to A conversion, the “.1” channel
should be boosted 10dB. Whatever level the other five channels
can achieve, the .1 channel has the headroom to play up to
10dB louder. Hopefully, the recording engineers will use this
extra headroom sparingly. Unfortunately, the recording of the .1
channel seems to always be recorded at its maximum level. This
can lead to problems of balance with a normal home theater
system for the following reason: If small speakers are used with
a subwoofer, the subwoofer does double duty by reproducing a
combination of the bass from the five channels (music and dia-
log) and the .1 effects channel. For the music to sound full and
balanced, an exact setting of subwoofer level is required. This
might be a gain setting that often reproduces the .1 channel
(potentially 10dB louder) at too high a level, causing overdrive
or at least an excessive effects level.
Some processors are now giving setup options that allow trim-
ming of the LFE from Dolby-specified full gain (+10dB) down to
a lesser level. The music and cinema XA Towers also allow you
to set LFE level if you use a separate LFE input with its own level
adjustment potentiometer. This control is calibrated relative to
a processor with the Dolby-required +10dB LFE gain. That is,
setting it to 0 will give the same overall level. Setting it to -8
would be 8dB less than ”normal,” which is in fact 2dB of gain
relative to other channels. (The LFE gain calibration marks
assume your power amplifier has a voltage gain of about 26dB.)
This will allow you to control the LFE level independently of
other bass. When the LFE mix-level knob is set to 0dB, LFE mate-
rial will be reproduced at the full Dolby-specified mixed level.
Settings less than 0dB will change the proportion of the effects
level (explosions and the like) to music bass levels. This is best
set by finding a disc with a preponderance of LFE energy and
setting the knob until the balance between explosions and the
rest of the soundtrack seems “realistic.” Hint: One way of deter-
mining a good level is to set it to give (at a typical loud listening
level) a bit of gut feel to the explosions and gun shots. Extreme
settings will become fatiguing over time.
The above procedure is by no means mandatory. If you do not
wish to use separate connections for LFE, most processors will
send it to any channels designated “Large” with a configuration
choice of “no subwoofer.” In all cases, it is important to consult
the processor manual because some manufacturers have differ-
ent interpretations of what these designations mean.

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OPTIMIZING THE SOUND
LFE LEVEL
LFE INPUT
REMOTE LINK
POWER
ON
ALWAYS
ON
FUSE
T5A
250 V
60 HZ
120 V
550 W
MUSIC SENSE
AUTO
-8
-10
-12
-3
+3
MIN. MAX.
0
PARAMETRIC EQ
0
-2
LEVEL
(dB)
BANDWIDTH
(0ct)
+2
-5 +5
0.9
0.5
0.2 1.5
1.2
1.0
-10 +10
FREQ.
(Hz) 50
36
30
32 100
65
40
80
OVERALL
BASS LEVEL
OFF
XA 90ps Rear Panel
Subwoofer Amplifier Settings
The amplifier of your XA Towers contains a number of rear panel
controls, some of which should be set upon installation and
then generally left alone. The remote control (XA 90ps) contains
additional controls for user adjustment according to taste or
program material.
It is best if a qualified installer aids in this initial setup, hopefully
with a 1⁄3-octave real-time spectrum analyzer and a pair of good
ears.
Overall Bass Level
This control sets gain for the bass amplifier that determines bass
level for the normal (speaker level) input and also the LFE line-
level input. Note: In the XA 90ps, overall bass level is a combina-
tion of the levels set by this knob and by the remote control.
Use the remote control to set the amplifier to the 0 position.
Adjust the bass level to give a solid but not overblown bass level.
Confirm this on a variety of program material. If using a spec-
trum analyzer, set to a level so that frequencies below 100Hz
are flat (or up to 3dB up from flat). The remote control (XA 90ps)
will then give a range of ±6dB in 2dB steps from this central
position.
Parametric Equalizer (XA 90ps only)
The XA 90ps is unique in including a bass parametric equalizer.
Through several years of experience with the amazing RCS1000
digital equalizer, we have learned firsthand the damaging effects
of the room on bass reproduction, and how careful equalization
can greatly reduce these effects. The dimensions and materials of
a room create “standing waves.” The locations of speakers and lis-
tener relative to these standing waves create uneven bass response.
The parametric equalizer of the XA 90ps allows you to pick the
room’s dominant bass problem and correct it. The end result is bass
response that will be more even, more musical, and less “resonant.”
The term parametric equalizer stems from the fact that all parame-
ters of an equalizer section are adjustable. This includes bandwidth
(also called Q), frequency, and level. With the parametric equalizer,
you have the option of making broad effects (more or less low
bass; more or less mid-bass) or tackling narrow band effects, such
as notching out a room resonance at 70Hz.

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10.00
5.00
2.00
-2.00
-5.00
-10.0010 100 1K
Frequency (Hz)
0
Although such a system could be tuned via a skillful ear, it is
better to enlist the help of a real-time analyzer. This is a piece of
instrumentation that analyzes the spectrum of any signal received
by the microphone. Pink noise (which has a flat perceived spec-
trum) is fed from the instrument to the input of the amplifier
or processor. The resulting spectrum will show room effects. The
parametric analyzer can then be adjusted to dramatically improve
the typical room response. Correcting the room response will
create a more even, musical, and faster-paced bass performance.
To make an adjustment, first choose the aberration to correct,
then match the filter to its frequency. Starting with extreme set-
tings of the other two controls (highest Q and full cut or boost)
can most easily do this. Then, while watching the spectrum
analyzer, the frequency can be adjusted up and down until
your correction frequency and aberration frequency are seen to
coincide. This adjustment of bandwidth and level (+ or –) will
flatten the response. Caps are provided to seal the parametric
controls once they are optimally set.
Hints:
¤Live with the system for awhile to learn its bass character. Then
tune to correct its dominant flaw.
¤Measure the bass of each channel over a variety of positions
encompassing the listening area. Correct for the average
curve of the area.
¤Use your ears to confirm the final settings. Dial in the boost
or cut amount by ear. Don’t worry if the final setting disagrees
somewhat with the “best” setting according to the spectrum
analyzer.
¤Adjustment of the parametric equalizer may require further
adjustment of bass level. Juggle the settings of one control
against the other.
¤It is important to have a good match between the final
response of both channels.
10.00
5.00
2.00
-2.00
-5.00
-10.0010 100 1K
Frequency (Hz)
0
10.00
5.00
2.00
-2.00
-5.00
-10.0010 100 1K
Frequency (Hz)
0
0
-2
LEVEL
(dB)
+2
-5 +5
-10 +10
Level
Bandwidth
Frequency
Control
Cap
Parametric Equalizer Range

16
Bass Shape Control
The rolloff rate and the shape of the low-frequency corner of a
subwoofer affect its sound. For example, a subwoofer with a
“soft” corner and a gradual rolloff rate below its range of operat-
ing frequencies will generally give a tight and rhythmically “fast”
character. A system with a low-frequency corner that is squarer
and rises slightly before falling off quickly will provide a more
robust low-frequency sound. Additionally, the faster rolloff will
give a better compromise in terms of apparent bass output
versus woofer power capability. The Snell XA Towers offer both
options via a rear panel switch on the XA 75ps and via the remote
control of the XA 90ps. Some people prefer the “Reference” posi-
tion for music and the “Cinema” position for movies. Try either
setting and use whichever one suits your mood, your room
acoustics, or your program material.
XA Towers, Crossover Controls
Setting the Placement Switch (Input Terminal Plate, far
left switch)
Freestanding placement:
Set the Placement Switch to NORMAL.
Boundary placement:
Set the Placement Switch to BOUNDARY.
Asymmetrical placement:
Based on your room layout, you might find that one speaker
performs best in the BOUNDARY setting, and the other in the
NORMAL setting.
Setting the Treble Level (Middle Switch XA 75ps, Remote
Control XA 90ps)
¤The Treble Level Control contours the “brightness” of the
XA Tower. Turn the Treble Control to +to increase the high-
frequency output in situations in which the XA Tower
sounds dull.
¤Turn the Treble Control to -when the XA Tower is overly
bright, especially in highly reflective rooms.
¤The + position is closer to ”anechoically flat,” although much
recorded music will be preferred in the - position.
¤The - position is similar to a processor cinema ”re-EQ” setting.
Setting the Rear-Firing Tweeter (far right)
¤The rear-firing tweeter adds spaciousness and ambiance to
the soundstage, and is particularly effective when the XA
Tower is placed at least 12 inches (30cm) from a back wall.
Turn the Rear-Firing Tweeter OFF When:
¤The XA Tower is placed directly against a back wall.
¤The soundstage sounds too bright for your taste.
Center Channel—Setting the Placement Switch
TV top placement:
Set the Placement Switch to NORMAL.
Cabinet placement:
Set the Placement Switch to BOUNDARY.
LFE LEVEL
BASS SHAPE
LFE INPUT
-8
-10
-12
-3
+3
MIN. MAX.
0
OVERALL
BASS LEVEL
REFERENCE CINEMA
95
90
85
80
75 20 Frequency (Hz)
10050
reference
cinema
XA 75ps Rear Panel
Bass Shape Effect
OPTIMIZING THE SOUND (CONT.)

17
Infra Red Control, Command Cable
The remote control for the XA 90ps uses Infra Red (IR) to send
commands to both speakers. Generally, both speakers will see
commands through uninterrupted distances of up to 30 feet.
Sometimes, one of the speakers might not see the IR signal, so
we have included a cable to transfer commands from one tower
to the other. You might find a time where you are at the limits
of reception, with one speaker blocked, or perhaps aiming
toward one system and away from the other. In these cases, the
system that receives the commands will pass them on to the
other, thus assuring the best reception and that the two speak-
ers remain in sync.
Connect the supplied cable from speaker to speaker through
the jacks marked “remote link.” If a longer cable is required for
a special routing or for running wires through walls, it can be
custom-made using well-shielded coaxial and standard mono
1⁄8-inch minijacks.
The control handset gives you control of bass level (in 2dB
steps) of bass rolloff shape, and of treble level.
Turn On Mode
The XA Towers include a feature for automatic turn on. The
subwoofer amplifier will come out of its low-power standby
mode when it senses a signal. A multicolored LED will designate
what state the amplifier is in. Yellow indicates standby, and
green indicates on. After the signal ceases, the system will revert
to standby mode in approximately 8 to 10 minutes. Both
speakers will not necessarily turn off at the same moment. As
an alternative to automatic turn on, the speaker can be set
to be always on. To choose between these two options, use the
switch marked “MUSIC SENSE-AUTO/ALWAYS ON.”
In some systems, the electrical noise floor (due to hum, refriger-
ator, or furnace-turn-on pops, etc.) is such that Music Sense-
Auto turn on is erratic. In this case, we recommend that the
switch be set to ALWAYS ON and manual switching via the main
power switch be used.
Power On
The main power switch is situated below the power input lead.
It is a rocker-type switch marked with a ”1” and a ”0.” Pressing
the end marked ”1” will turn on the main power to the system.
Some people prefer to turn off the main power if they know
that they will be gone from the house for an extended period
of time.
SPECIAL FEATURES
BASS LEVEL
+6
+4
+2
0
-2
-4
-6
BASS SHAPE
TREBLE
Cinema
Reference
Boost
Cut
Remote Control
(XA 90ps)
Remote Link Cable

18
The power recommendation for the system assumes you will
operate the amplifier in a way that will not produce distortion.
All speakers can be damaged by a modest amplifier if it is pro-
ducing distortion. If you hear a gritty noise or other signs of
strain, turn down the volume. Prolonged or repeated operation of
your speakers with a distorted signal can cause damage that is
not covered by the warranty.
For Painted Finishes
Including fronts, backs, bases, and metal grilles.
¤Use a soft terry cloth towel slightly dampened with water or a
diluted mild detergent. The towel should be just damp enough
to wipe the surface clean without leaving a trail of moisture.
¤Do not use abrasive cleaners or any cleaner containing chemi-
cals harsher than those found in glass cleaner.
For Oiled Natural Wood Finishes
To remove dust and fingerprints, use the same technique as
above.
¤If your veneer begins to dry, apply a light coat of rose or
lemon wood oil. This should return the wood to its original
richness.
¤Do not use spray waxes. These will create a buildup and
eventually cause the veneer to appear dull and lifeless.
Note: Your veneer’s appearance and color will mature and per-
haps darken over time.
¤Avoid placing speakers in extreme conditions. If direct sunlight
is unavoidable, be sure that there is nothing partially covering
the veneer in order to prevent ”tan lines.”
¤Avoid placing speakers where they could be subjected to
standing water. It will cause the wood to swell, breaking apart
glue joints and ruining the air seal.
Grilles
You can remove the grilles from the speaker system and wipe
them with a damp cloth to remove any dust.
Amplifier Protection
The subwoofer amplifier contains protection against fault condi-
tions of excessive DC output or thermal overload. If triggered,
the rear panel LED will glow red. Protection circuitry is not self-
resetting. To reset, turn off the main power switch, wait several
minutes for the unit to cool (if hot), and restore the power.
If this does not reset the LED to yellow or green, disconnect
the input and repeat. If this still does not remedy the fault,
contact your dealer or Snell Acoustics for service. If disconnect-
ing the system’s input restores the system to normal, associated
equipment is suspect and should be checked.
LISTENING LEVELS AND POWER-HANDLING
HOW TO CARE FOR YOUR SPEAKERS
SPECIAL FEATURES (CONT.)

Warning: To reduce the risk of fire or electric shock, do not expose this product to rain or moisture.
The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of
uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of
electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert you to the presence of important operating and
maintenance (servicing) instructions in the literature accompanying the product.
19
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
SAFETY INSTRUCTIONS
1. Read Instructions: All the safety and operating instructions
should be read before the product is operated.
2. Retain Instructions: The safety and operating instructions
should be retained for future reference.
3. Heed Warnings: All warnings on the product and in the
operating instructions should be adhered to.
4. Follow Instructions: All operating and other instructions
should be followed.
5. Water and Moisture: The product should not be used near
water—for example, a bathtub, washbowl, kitchen sink, laundry
tub, in a wet basement, or near a swimming pool, etc.
6. Carts and Stands: The product should be used
only with a cart or stand that is recommended by the
manufacturer. A product and cart combination should
be moved with care. Quick stops, excessive force, and
uneven surfaces may cause the product and cart combination
to overturn.
7. Wall- or Ceiling-Mounting: The product should be
mounted to a wall or ceiling only as recommended by the
manufacturer.
8. Ventilation: The product should be situated so that its loca-
tion or position does not interfere with its proper functioning.
For example, the product should not be situated on a bed, sofa,
rug, or similar surface that may obstruct the heat sink surfaces;
nor placed in a built-in installation, such as a bookcase or cabi-
net that may impede the flow of air near the heat sink surfaces.
9. Heat: The product should be situated away from heat sources
such as radiators, stoves, or other products that produce heat.
10. Power Sources: The product should be connected to a
power supply only of the type described in the operating instruc-
tions or as marked on the product.
11. Grounding or Polarization: This product may be equipped
with a polarized alternating-current line plug (a plug having one
blade wider than the other). This plug will fit into the power
outlet only one way. This is a safety feature. If you are unable to
insert the plug fully into the outlet, try reversing the plug. If the
plug should still fail to fit, contact your electrician to replace
your obsolete outlet. Do not defeat the safety purpose of the
polarized plug.
12. Power Cord Protection: Power supply cords should be
routed so that they are not likely to be walked on or pinched by
items placed upon or against them. Pay particular attention to
cords and plugs, convenience receptacles, and the point where
they exit from the product.
13. Cleaning: The product should only be cleaned as recom-
mended by the manufacturer.
14. Nonuse Periods: The power cord should be unplugged from
the outlet when left unused for long periods of time.
15. Object and Liquid Entry: Care should be taken so that
objects do not fall into and liquids are not spilled into the inside
of the product.
16. Damage Requiring Service: The product should be ser-
viced if any of the following events occur:
A. The power supply cord or the plug has been damaged;
B. Objects have fallen or liquid has been spilled into the
product;
C. The product has been exposed to rain;
D. The product does not appear to operate normally or
exhibits a marked change in performance; or
E. The product has been dropped or the enclosure damaged.
17. Servicing: The user should not attempt to service the prod-
uct beyond what is described in the operating instructions. For
all other servicing, consult your dealer or contact Snell Acoustics.
S3125A

©1998 Snell Acoustics. All Rights Reserved. ”Dolby” is a trade-
mark of Dolby Laboratories. Confidential Unpublished Works.
©1992-1997 Dolby Laboratories, Inc. Specifications are subject
to change without notice. Covered by patents issued and or
pending.
Part #542-1005
For five years from the date of purchase, Snell Acoustics will
repair for the original owner any defect in materials or work-
manship that occurs in the drivers (woofer, midrange, tweeter)
of the XA 90ps, XA 75ps, or XA 55cr without charge for parts and
labor. For two years from the date of purchase, Snell Acoustics
will repair for the original owner any defect in materials or
workmanship that occurs in the amplifier of the XA 90ps or XA
75ps, without charge for parts and labor.
Your responsibilities are to use the system according to the
instructions supplied, to provide safe and secure transportation
to an authorized Snell Acoustics service representative, and to
present proof of purchase in the form of your sales slip when
requesting service.
Excluded from this warranty is damage that results from abuse,
misuse, accidents, shipping, repairs, or modifications by anyone
other than an authorized Snell Acoustics service representative.
This warranty is void if the serial number has been removed or
defaced.
This warranty gives you specific legal rights, and you may also
have other rights which vary from state to state.
If Service Seems Necessary
Contact the dealer from whom you purchased the speaker sys-
tem. If that is not possible, call us at 978-538-6262, or
write to: Snell Acoustics
300 Jubilee Drive, POB 3717
Peabody, MA 01961-3717
We will promptly advise you of what action to take. If it is nec-
essary to return your speaker system to the factory, please ship
it prepaid. After it has been repaired, we will return it freight-
prepaid in the U.S. or Canada. Reuse your original packaging for
all shipping.
300 Jubilee Drive, P0B 3717
Peabody, MA 01961-3717
phone:[phone]
fax:[phone]
LIMITED WARRANTY