Zu Audio DEFINITION Mk.IV User manual

DEFINITION Mk.IV
OWNER’S MANUAL
1 | 2012

THANK YOU
Thank you for your purchase of the Zu Audio Definition Mk.IV loudspeaker system. Every
element is designed for a lifetime of hassle-free high-performance playback. It’s our intent
that these loudspeakers exceed every reasonable expectation in product performance, quality,
durability and customer service, for as long as you own them.
Evidence your new loudspeakers are designed for a lifetime of use is the engineered-in
serviceability—in the unlikely event of needing to replace a damaged driver, or subwoofer
amplifier, Definition Mk.IV is easy to service in your home using simple tools, with no exposure
to safety hazards, and no real down time or the hassle of having to package and ship the entire
loudspeaker back to the factory. So sit back, and enjoy!
ZU VISION FUTURE & PAST
Impressions of new realities struggle and flow—eventual transition.... Awareness of
surroundings, songs of tranquility and warning—history and intuition instruct that patterns of
sound have been a fundamental constant. Observance of nature, both physical and spiritual,
teach us of the endless interplay of vibrational forces.
While traveling the line of time we observe many periods of increased awakening and
technological advancement but none so powerful and rapid as that of the Scientific Revolution,
Enlightenment and the birth of modern physics. The dramatic increase of understanding
regarding possibility, vibration and energy coincide with our collective ability to listen and
express patterns of life. David Toop in his book Ocean Of Sound paints a powerful image of
our modern musical creativity: “...Starting with Debussy in 1889, is an erosion of categories,
a peeling open of systems to make space for stimuli, new ideas, new now, this environment
included sounds of the world—previously unheard musics and ambient sounds of all
kinds, urban noise and bioacoustics... unfamiliar tuning system and structuring principles,
improvisation and chance.”
Welcome to Zu

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV (((WARNINGS)))
WARNINGS
Never leave children unattended in your playback room. Even though Definition has a wide
base, care should be taken to prevent accidents from a toppled loudspeaker.
(Besides, you already know if you let them in your room uneducated and unattended they are
going to bust your needle, play catch with your discs, bend your tube pins, and write their name
on your new leather chair—good secondary reasons for spending time with ‘em. So hang with
your kids, grand kids, and neighbor kids, listen to some great music together, teach ‘em about
playback and great music. Introduce them to Lucinda Williams, The Clash, Miles, Hendrix,
Beethoven, Zeppelin, Sinatra, Rush, Silver Jews, Debussy, Woody Guthrie, Deep Purple,
Wagner, Black Keys, Marty Robbins, Kyuss, Spoon, Steve Earle, Sabbath, Velvet Underground,
Eels, CVB, Joanna Newsome, Ry Cooder, Cash, Ryan Adams, Zappa, John Prine, The Who,
Ian McKay, Zakk Wylde, Sex Pistols, Julian Cope, Alice In Chains, Legendary Pink Dots... the
Stones, Charlie Parker, Hank Williams, Elvis, Beetles and Mozart.)
WARNING: RISK OF ELECTRIC SHOCK—THERE ARE NO USER-SERVICEABLE PARTS INSIDE
THE AMPLIFIER.
The drivers and the complete subwoofer amplifier are user replaceable without risk of electric
shock. Risk is only if the subwoofer amplifier is disassembled and circuits and power supply
components are exposed. This requires special tools and technical skill. If the subwoofer
amplifier is opened for any reason know dangerous voltages are present inside during operation
and for up to ten minutes after disconnecting from AC mains. Again, the subwoofer amplifier
case is sealed and requires technical knowledge and special tools to open, and should only be
serviced by a qualified technician. This loudspeaker system is not intended for outdoor use, do
not expose to rain or moisture.
Also, we recommend unplugging your loudspeakers, main amplifier(s) and electronics during
lightning storms or when the playback system will not be used for an extended period of time.
WARNING: Electrocution through loudspeaker cable is possible, though very unlikely. Still,
to avoid electrocution make sure your amplifying gear is switched off prior to connecting
or disconnecting. This will also reduce the possibility for accidental damage to your audio
amplifier.
WARNING: Definition Mk.IV loudspeakers are heavy. We highly recommend you have a second
person or professional furniture mover assist you.
WARNING: Definition Mk.IV loudspeaker drive units create stray magnetic fields that extend
far beyond the boundaries of the cabinet. We recommend you keep magnetically sensitive
electronics and media at least four feet [1.2m] from the loudspeaker.
WARNING: Definition Mk.IV loudspeakers are capable of extreme sound levels, play responsibly.
If caution is not exercised your hearing will be damaged. And your neighbors will either hate
you or want to party with you.

DEFINITION MK.IV UNPACKING
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UNPACKING
Definition Mk.IV features our new FlexPak foam-encapsulating shipping containers. They are
extremely protective, lightweight, simple, and reusable.
WARNING: Consider hiring a professional furniture mover, or at least inviting a few of your
buddies over to give you a hand, each speaker weighs about 165 pounds [75kg].
CAUTION, watch out for snaps, rivets, jewelry, and belt buckle scratching the cabinets when
positioning the loudspeakers.
1. Make sure your path is clear and your room is made as open as possible. If lifting is
required, lift with your legs and not your back, and with the assistance of a friend or two.
2. Lay a moving blanket, or similar, down on your floor.
3. Using a hand truck, wheel one speaker into the room and lay it on its side. The freight
company usually has a hand truck on board and will likely let you borrow it for a few
minutes while you wheel them inside. And tip the driver if you borrow the hand truck.
NOTE: UPS Freight and others are not allowed to enter your house, if you are nice they will
likely wheel the speakers right up to your door, maybe lend you the hand truck for a minute
while you move them into your room. But even if you give them a big tip, they are not going
to lend any muscle inside your home.
4. Cut the banding wrap with a knife, and while still laying down, cut the tape securing the
tabs on either end of the box. You do not need to cut the box off the speaker, be nice to
your box and save the packaging.
5. Sit down in front of one of the open ends, grab the box flaps with your hands, and with your
feet press the foam encapsulated speaker out the other end.
6. With the speaker still horizontal, remove one of the foam halves, then gently roll the speaker
over and remove the other foam half. Leave the plastic wrap on. Careful of the lower rear
portion of the speaker where the amp’s knobs and switches are located.
7. With the speaker still horizontal and wrapped in plastic, confirm the ball-end footers are
installed in the base. If the speakers will be standing on carpet or on a rug, peel back the
plastic wrap to expose the base and feet, remove the ball-end studs and replace them with
the supplied spikes.
8. Lifting the top of the speaker, pivot onto its feet.
9. Move speaker into position and then remove the plastic wrap.

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV PLACEMENT
QUICK TIPS ON GETTING GREAT SOUND FROM DEFINITION MK.IV
Definition Mk.IV loudspeakers get 400 hours of factory burn-in, they will sound good right out of
the box but will not give you their best for a few weeks, depending on how much play, and how cold
they got in shipping, as well as what kind of music they see. If shipped in the winter months you can
expect them to need the first week to warm up and start sounding good, not sure why, it just is.
Make sure you have 1/4” [6mm] or greater gap between the bottom of the loudspeakers and the
floor, the down firing sub needs a bit of space, but less than you would think considering the big
subwoofer behind the fluted feature.
In addition to the installed ball-end footers (for hard surface flooring) Definition Mk.IV also ship with
spikes that are to be used to punch through and anchor the speaker on carpets and rugs.
INITIAL PLACEMENT
While your initial placement for the Definition Mk.IV loudspeakers may not be the acoustic ideal,
know they are not hyper-sensitive to where in your room they are placed and you should get
satisfactory performance from most any position. Nevertheless, you will be rewarded if you work
on setting them up for the best sound. The following details may assist you in the pursuit of tone,
texture, and realistic stereophonic recreation.
Placement for left / right front: Definition Mk.IV loudspeakers should be placed to work with the
natural acoustics of the room rather than fight them. The following basic points should be followed.
• Definition loudspeakers should be equidistant for compelling stereo performance.
• Generally, Definition loudspeakers should be placed no closer than two feet [60cm] from a side
wall. This distance is measured from the center axis (Y axis) of the loudspeaker and not the side.
• The angle between the speakers, measured at the central listening position, should be between
60 and 110 degrees. Wider is usually better for both stereo and home theater. But this angle is
largely determined by your room and personal preference.
LOUDSPEAKER FEET
Hard surface ball-end feet have been pre-installed in the Definition Mk.IV and carpet spikes
have been included in the package. Ball-end footers are more gentle on hard surface flooring
but will mar it, especially if slid. We recommend you lift and move the loudspeakers to avoid
damage. For carpeted floors we recommend that you use the supplied spikes. Spikes provide
increased support to the loudspeaker, allowing it to couple with the structure of the floor
and not wobble about on the carpet. Carpet spikes will also reduce permanent carpet or rub
impression from the loudspeaker.

DEFINITION MK.IV TUNING
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PLACEMENT FINE TUNING | BASS
Perhaps it has been the lack of skilled engineers, maybe audiophiles at large have lacked
discipline, for whatever reason the current consumer playback world is lost in its perception
of acoustics and the nature of sound—much has been written in consumer magazines but
little of it is genuine. Original recommended works on the subject include: Music, Physics
and Engineering (formerly titled Musical Engineering) by Harry F. Olson, Science & Music by
Sir James Jeans, Fundamentals Of Musical Acoustics by Arthur H. Benade, Fundamentals Of
Acoustics by Lawrence E. Kinsler, Austin R. Frey, Alan B. Coppens and James V. Sanders. There
are many other good sources of researched data; those mentioned represent a good cross-
section.
The following technique is Zu Definition specific. It addresses the loudspeaker’s relationship
with the room and works for both two-channel and multi-channel setups.
How and where the loudspeakers excite a room and how a room reacts are relative to the type
and source of excitation and room reactance—a function of boundaries (walls, floors, etc.);
boundary properties (mass, compliance, Q, damping, texture and structure); area impedances
(shape, volume); diffusion and absorption (furnishings, people, flooring, etc.); source and type
of wave excitation (loudspeaker design and placement); resonators (closets, forced air ducting,
hallways, etc.); even atmospheric pressure and humidity, though very minor, will influence
sound. While the above are beyond the scope of this manual, the recommendations and listed
books will start you down the proper acoustic path. Again, before you trust another modern
work relative to playback and acoustics please research the above listed references.
With your loudspeakers positioned for visual appeal, livability and fidelity, you can now begin
fine-tuning. This involves three major steps: in sequence they are bass, mids and treble. If you
can’t fine-tune your system within an evening or two please contact us, we’re here to help.
If you have one loudspeaker that is framed with more wall space than the other, this is the
loudspeaker you will fine-tune and then simply mirror the other. Select recordings with large
amounts of sustained low frequency information; dramatic pipe organ and dance music work, as
do test recordings that have warbled low frequency tracks (50~100Hz range). Note that steady-
state sine, triangle and square wave signals prove very difficult to interpret. Bass information
with some transient content will enable the listener to make fast work of fine-tuning.
With the loudspeaker playing at a moderate level, (VERY IMPORTANT—only the ‘tuning
loudspeaker’ should be connected and ‘on’) walk over and kneel down next to it. Kneeling
will put your head in the seated listening horizontal plane and allow you to hear how the
loudspeaker integrates with the room. Now move your head and ears in all directions around
the vertical axis of the loudspeaker, say a few feet or so [.5m] on all sides. Listen to the fidelity
of the bass, does it sound woolly and muddy right behind the loudspeaker? Is the bass more
defined a bit to the left or right? If the bass sounds better a bit to the left, move the loudspeaker
to this position and then listen again. Remember, moving the sound source also changes how
the room reacts. You should not have to move the loudspeaker more than several times
to get it right.

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV TUNING
PLACEMENT FINE TUNING | MIDRANGE
Once the lower octaves are sounding good, natural and vibrant midrange and treble can then
be dialed in. Before you begin, it’s important to understand a few details about midrange
tuning. While similar to that of bass, midrange is a task of inches [decimeters] rather than feet
[meters], and upper octaves a matter of fractions of an inch [centimeters] and loudspeaker
firing axis (wavefront and where they face). And while midrange and treble changes can be
heard at the ‘being positioned loudspeaker’, it is much more helpful to have a friend do the
positioning while you listen from the sweet spot/listening position. Select lighter recordings for
this—singer-songwriter, folk, jazz, space-ambient, violin solos, acoustic guitar, and so on—
music with good overtone color and not too heavy.
Staying with the same loudspeaker tuned for low frequencies, (remember you only tune one
channel and then mirror its mate) and with your favorite light recording playing, start tuning for
mids and highs. Move the speaker toward the closest wall an inch or two at a time [3~6cm].
The sweet spot observer, and possibly the person positioning the loudspeaker, should notice
midrange color and presence transition from low and masked to open and intimate—that’s
the goal anyway. There may be several spots within the good sounding bass area that have
good presence, go with the widest point (closest to the wall) for an expansive and engaging
stereophonic soundscape. Don’t worry about center focus, Definition Mk.IV can really throw an
expansive and focused image (provided it’s in the recording and passes unhindered through the
electronics—there’s nothing worse than some stupid whizbang technology forever synthesizing
space and tone).
PLACEMENT FINE TUNING | TREBLE
Once a midrange position is selected it’s time to work on the highest octaves. This is usually
as simple as rotating the Definition Mk.IV loudspeaker to face directly at the seated listener—
pivoting the speaker on its front inside spike. Now listen again for soprano voice and light
instrument openness and intimacy, minor placement adjustments and face angle will likely be
necessary. Realize that best placement may change with speaker age, electronics upstream,
and other variables. The simple guideline is if it’s a bit treble rich, rotate each speaker to focus
behind the main listening area a few feet—experiment. And yes, this same technique works for
other Zu speakers, and most others you might be proud to own.
ADJUSTING LOUDSPEAKER FEET & BAFFLE CANTING
Spikes for carpet, ball-end studs for hard surface floors. Once positioned and tuned-in, your
last step is to level the loudspeakers by adjusting the spike or ball-end studs. Each loudspeaker
should stand straight and level and all four contact points should be equally weighted. If you
have a high listening position you can cant the loudspeaker back, lowering the rear feet / rasing
the front feet. This rotates and elevates the stereophonic image.

DEFINITION MK.IV FINE TUNING
FRONT WALL
768 5
99
4
3
SEATING
60˚
1
2
TWO-CHANNEL STEREOPHONY TUNING
Recommended tools: tape measure, masking tape, Strait-Line® intersect laser level, or similar
(inexpensive and useful for leveling wall art when you aren’t using it for fiddling with your hi-fi).
With the one loudspeaker now tuned and sounding good, getting convincing two-channel
stereophonic effect is now simply a matter of measuring and mirroring. Don’t fuss over whether
or not your loudspeakers are perfectly square with the walls, or get obsessive with the room’s
mathematical relationship. To do so is to waste time and possibly mess things up. Trust what
you’ve already established with your single-channel effort so forget about everything other than
establishing your center plane and mirroring the other channel.
In the mono ‘speaker you established two points of reference that will now establish your two-
channel stereo mirror plane. Those points are your seating position and your tuned loudspeaker.

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV FINE TUNING
(Reference illustration—two-channel stereophonic loudspeaker setup)
1) Measure and note the distance from the wall behind to the positioned
loudspeaker’s inside forward base corner.
2) Sit in your center seat, mark the center spot of the floor right between your feet
with a bit of masking tape.
3) With the Strait-Line® intersect laser level in hand, stand and walk straight ahead
to the facing wall. Butt the intersect laser level up against the wall and position the
laser so the side plane laser indicator runs parallel with the wall, and the center plane
intersects your seating center mark.
4) From the wall, along the center laser mark pointing at your chair, measure the
same distance as in step one, and mark with a bit of tape. These two points establish
your stereo center plane.
5) Move the intersect laser level forward so the intersection is on that bit of masking
tape nearest the wall and the center laser mark intersects your seating center mark.
This should result in the orthogonal laser striking the tuned loudspeaker right on the
inside front corner.
6) Measure and note the distance from the laser intersect to the point of laser contact
(inside front base corner) on the positioned loudspeaker.
7) Reflect this distance on the other side of the stereo plane, marking the mirrored
distance with tape.
8) Now place the second speaker’s inside front corner on this mark and approximate
the toe-in by pivoting it on this inside front corner. If fine tuning of toe-in is needed
pivot either loudspeaker on the front inside corner footer only. This will keep the
mirrored stereo relationship the same and you won’t have to get the laser and tape
measure out every time you mess with toe-in.
9) While you can also use lasers to adjust and ensure mirrored stereo toe-in, we
recommend that initially you eyeball it based on the amount and angle of the
loudspeaker’s visible inside cabinet edge. Before you get “laser crazy” with toe-in
we highly recommend that after you get close, by eyeballing it, you then level your
loudspeakers, or start messing with firing axis (canting and elevation) for which the
laser is also a very handy, sometimes essential tool.

DEFINITION MK.IV REASONING
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
ADDITIONAL DECLARATIONS ON ‘THE ZU SOUND’ & GETTING IT WITH DEFINITION MK.IV
Definition Mk.IV gets closer to the music by defying many of the conventions of contemporary
loudspeaker design. Problems of tone, intimacy, room... and how to recreate a real sense of space
and grandeur that is music, these are the things that we’ve tried to address with our new ‘speaker.
Definition Mk.IV is about realizing elegant solutions and removing over-engineered and tone-
robbing modern convention, to deliver genuine expression, agility of attack and dynamic contrast,
with the lush sensuality of sustain, and the space, warmth and emotion expressed within decay.
Some of the design features that make it possible include the new full-range nanotech drivers and
their position on the loudspeaker. Consider that the attack of the whole musical scale emanates
from the front driver array—it’s only the subcontrabass, the really deep stuff, that’s recreated
from the user-tunable down-firing subwoofer system. Adjusting only the deep bass for great
in-room timbre is the best place to solve room problems without damaging the attack. And it’s
the attack more than any other aspect of a waveform that gives the listener the clues to process
source, direction, amplitude, character, intelligence... the light and life of music and sound.
Example: a piano key is struck! The bite of the impinging hammer, initial complex string motion,
and initial coupling of piano body and sound-board. The first milliseconds are very dynamic
and dense with feature. To get the attack correct is solely a function of the playback system and
has very little to do with the room—aside from placement. If you have changed your system to
combat room modes, attack and dynamics have very likely been impaired. Why? Because most
people can only pinpoint tonal problems with steady-state or semi steady-state music or signal.
This is a problem because room influence on steady-state is huge, the single largest influence
if included as a component of your playback system. So people usually tweak things to get the
steady-state and decay tonally correct but inadvertently kill the life in the attack. This is a reason
why cables as tone controls, digital room correction, parametric equalizers and the like can never
fix fundamental problems when used on the system as a whole—unless of course the time axis
is also programmed and correlated to harmonic structure and then set to react to any dynamic
anomalies within the signal, overlaid with the signature of the room the original recording was
made in and compared... (how much are real super computers going for these days?)
As a result of all the above, we think the pursuit of measured perfection, as displayed on a
‘scope or graph, is a distraction, with design choices being made to serve the spec’s rather than
the ear; it distracts from delivering the totality of a musical performance intended not just to be
heard, but to be felt. The tone, intimacy and dynamics of live music are everything to us so the
measurements we conduct in the design process are just a help to guide us along the way. So,
once we’ve got our ‘speakers sounding fantastic to our ears, we become rather less interested
in how they sound on paper. What we do care about, passionately, is how our ‘speakers perform
in the real world, surrounded by the ephemera of normal life and the reality of regular gear. At
the end of the day, when we crack open a beer, slip on a record and put our feet up, the only
measurements that matter are those read by our heart and soul via those appendages on the
sides of our heads. So if you just want to be transported to the place and the time, to experience
the creative energy, the rush of the attack, the sensual beauty of the sustain and all of those other
immeasurable yet defining ‘things’ that make music alive, there’s every chance you’ll fall in love
with the Definition Mk.IV every time you ask them to playback ‘that’ song, album, or sound.

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV INFORMATION
LOUDSPEAKER SYSTEM OVERVIEW AND SALES COPY
Definition Mk.IV is designed to give its best performance in midsize and larger rooms, on the
end of any good sounding amps, tubes or solid-state. Definition Mk.IV distills everything we’ve
learned from creating our flagship loudspeaker, Dominance, into a loudspeaker within reach of
mere mortals.
Definition Mk.IV takes from Dominance our new nanotech full-range drivers, the fabulous
Radian 850 based tweeter and our Event cable. It uses our Zu-Griewe acoustics technologies
for the full-range drivers, and cabinet engineering that addresses noise and framework
function across all fronts: materials, structural, bonding and building technique. The resulting
combinations of engineered plate, hardwoods, damping compounds and metal alloys create a
wonderfully inert structure.
Old Definition’s rear-firing sub-woofers are replaced with a single massively motored 12”
subwoofer driver, mounted on a super rigged, machined-from-billet 2” [50mm] thick block of
aluminum, firing straight down into the floor—this is powered by our new deep bass amplifier
built around the highly regarded Hypex UcD 400 module. This new on-board subwoofer
amplifier system is not only as good as it gets in quality power, it also provides transparent filter
processing of deep bass signals, most of which are user adjustable so you can dial-out room
modes without compromising the analogue integrity of the music fed from your main amplifier.
These components, and the sophisticated cabinet, work together to deliver what we genuinely
believe to be the state-of-the-art in any loudspeaker south of $30k. It’s hugely dynamic,
massively sensitive, capable of handling high power if you really want to die young, and so
wonderfully, gloriously coherent, unflappable and downright true to the gorgeousness of music
that we might as well retire now and go home.
The most visible change for Definition Mk.IV is the machined aluminum plinth and subwoofer
assembly. And while the cabinet size and shape look very similar to previous Definition models,
the Mk.IV cabinet design solves resonance and baffle issues in a completely new way, focusing
on structural and materials engineering and only using weight and mass where useful. The
substructure is a 30 degree raked dual wall superstructure that solves material resonance and
acoustics issues through elegant design simplicity. The baffle is the most unsound section
of any loudspeaker cabinet, yet it’s the portion of the cabinet with the greatest impact on
fidelity. With Definition Mk.IV we use the massive tweeter assembly as a stressed member of
the framework, compressing 10 pounds [4.5kg] of 1-3/4” [38mm] thick steel alloy and 1-3/4”
[38mm] thick billet 6061 aluminum to constrain the cabinet core right between our two full-
range drivers, exactly where all this mass and strength will do the most good. The cabinet core
material is a combination of engineered and solid woods. Joints are first mitered then strong-
backed. The plinth / bass assembly is bolted into the cabinet’s superstructure to realize a
structurally strong, well-damped cabinet without the end result weighing a ton of bricks.

DEFINITION MK.IV INFORMATION
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
POINTS OF ENGINEERING & PERFORMANCE
• Zu nanotech full-range 16 ohm drivers parallel-wired presenting an 8 ohm system
impedance to the amp (32 ohm latent option for amps needing such a load e.g. OTL)
• Radian 850-based tweeter assembly (if there’s better... we haven’t found it)
• completely new cabinet design using expanded materials pallet
• Zu-Griewe acoustic design principles applied to internal damping
• Event B3 based cable harness
• ZuB3 interface via speakON 8-pole
• Hypex 400UcD V5 based internal bass amplifier
• user controls and parametric tuning of deep bass
• machined aluminum enclosure for electronics
• engineered for in-field serviceability
Definition Mk.IV is real high-fidelity, a sincere expression of our musical values—of what we
create and build at Zu. You can see the strategic use of the mixed materials pallet, judicious
use of silver in the cabling and high-pass network, and the uncompromising and intense focus
given to all the drive units and the way in which they work together as a whole and interface
with the cabinet—and how the whole loudspeaker system works within the room.
Like all Zu products, Definition Mk.IV is centered and weighted around the critical human voice
(A1, 55Hz, through A6 and all the possible harmonics, to approximately 10kHz). Serving this
critical region of tone is our nanotech 10” paper cone substrate-based full-range driver—the
same developed and used in the Dominance. So with tone, texture and definition realized in the
meat of the range, we’ve set about redefining the frequency extremes with Definition Mk.IV—in
very real terms as evidenced in the driver selection, and demonstrably evident to your ears,
chest, and soul.
THIRD GENERATION ZU-GRIEWE ELECTROACOUSTICS LOADING
Zu-Griewe driver / cabinet / room loading technology as applied in Definition Mk.IV exploits the
high-efficiency full-range drivers’ bass performance. This affords a seamless integration of the
subterranean tone and textures reproduced by the system’s subwoofer.
Zu-Griewe technology was developed by Ron Griewe and Sean Casey, with its beginnings in competition two and four-
cycle motorcycle engine exhaust systems for improving power output, with increased bandwidth, while reducing noise
and sound pressure levels over convention. More on the Zu-Griewe tech can be found in the FAQ section.

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DEFINITION MK.IV INFORMATION
NEW NANOTECH (ZU103ND/G1-16) FULL-RANGE 10” DRIVER
This new Zu driver delivers stunning attack, shove, resolution and bandwidth—as they should,
being lifted straight from our flagship loudspeaker, Dominance. Features include a maximal
motor for expanded dynamic contrast and reduced harmonic distortion; a lightweight neutrally
hung voice-coil assembly featuring a paper/Kapton former; a linear in-line layup of the inner
cone for best resolution of detail; a diamagnetic shorting assembly for dynamic damping of
the moving mass when playing at concert levels; nanotech paper cones designed to support
wide bandwidth; and a billet phase cone with concentric maximal length sequence diffusion
for smooth high frequencies. All this is anchored to a heavy cast aluminum alloy frame with
overbuilt bonded and riveted yoke/magnet/top-plate assembly.
In 2004 we began to experiment with cutting-edge DuPont nano-engineered coatings and
solids. The initial reasons were to realize the best possible gloss finish and one that would also
be far tougher. These nanotechnology engineered liquid solid ceramics, fibers and synthetic
resins performed as promised—so naturally we got busy experimenting on driver applications.
Here’s what we’ve achieved: the driver’s cone is a paper pulp substrate, processed with a liquid
solid matrix utilizing several nanoengineered materials. Some key components and compounds
include: nanosphere ceramics, synthetic epoxy, cristobalite, plus the use of amorphous fumed
silica and aircraft dope. The nano materials and application process reduce weight and increase
strength and propagation velocity without incurring any sacrifices in damping. The end results
are stunning—our new nano-sanctified full-range drivers sound dramatically better than any
previous generation Zu FRD. Expect to see a lot more of them!
We continue to watch and experiment with new fibers and mats as they are very promising,
especially what’s being done with buckypaper. For us however a tone-promising pulp-free
combination of these new materials has not yet been identified. Nothing has proven to be as
well behaved as natural fibers. There’s just something about paper. Its balance of strength,
propagation velocity and damping all contribute to that tone, texture and fidelity we pursue.
But add the right combination of old coating technologies plus nanoengineered materials and
adhesives... paper maintains its advantages well into the 21st century. For more info please see
the FAQ section of ZuAudio.com

DEFINITION MK.IV CABLE
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
WIRE AND CABLE
The most common abuse in hi-fi is to use cable as a form of tone control. Doing so usually leads
to frustration and further loss of fidelity. When cable affects timbre it affects timing, phase,
frequency response, and so on. Avoid using cables as tone controls.
Timbre problems are usually solved with loudspeaker break-in and correct loudspeaker
placement. If the cable has good properties relative to phase, gain, group delay, impedance,
and bandwidth, it will likely convey with fidelity the transmitted emotion and color. As an aside,
avoid taking other people’s opinions on cable as gospel—just because a reviewer makes blanket
statements about cable “sound” means little relative to your rig and your ears. So trust your own
ears, they’re yours for a reason. Also, bear in mind that just because you had a good sound with
cable A on loudspeaker X does not mean that cable A will be a good system match for Definition
Mk.IV loudspeakers.
For best stereophonic imaging you should run matched pairs of left / right cable of the same
length. If tone is more your thing and stereophonic effect is not so important then length
matching of left / right channels is not critical.
While insulation, jacket materials, pigments, conductor shape, metallurgy and structure are
important (yep, they really are), all pale into insignificance compared to the influence of
electrostatic / electromagnetic forces, virtual ground plane, and conductor relational geometry.
It is the E&M model, or cable geometry, that largely determines a cable’s measured attributes.
Improvements that will be noticed from well engineered cables such as ours should include:
enhanced bass depth and resolution, lower system noise floor, richer harmonic structure and
timbre, faster attack, greater stereophonic accuracy and an overall ease of listening—simply a
lot closer to real and satisfying and a lot further from typical hi-fi animation. But this assumes
you are striving for the natural. Preferences in playback are just that, and individual enjoyment
really is the goal, and not some ideal of what playback should be. Yes you can strongly feel our
hepcat bias, but that’s just us—do what makes you happy, and hopefully it includes some Zu.

DEFINITION MK.IV CONNECTIONS
ZuB3 CONNECTOR INFORMATION
All connections should be made with the equipment switched off, just to be safe. Definition
Mk.IV features a ZuB3 termination interface. It requires the use of ZuB3 terminated cable or the
use of ZuB3 to Cardas binding post adapters.
ZuB3 is a cable archetype that measures and performs differently than other cable formats
(twisted pairs, coax, braids, or ribbons)—a difference we believe significantly improves
performance. Zu Def-4 loudspeakers feature this cable geometry inside, and connecting Zu
cable from the amplifier to the loudspeaker via ZuB3 ensures best fidelity. Reasons include:
• maintaining the cable’s electric and magnetic features through the bulkhead of the speaker
• lower contact resistance (better than half the resistance of pure copper lugs and spades)
• ensured correct channel phase (SP+ to SP+ | SP– to SP–) as the connectors are indexed
• no possible short-circuiting of amplifier
ZuB3 interface connection via speakON™ 8-pole connectors maintains the electric and
magnetic properties of the ZuB3 cable and lowers contact resistance over other bulkhead pass-
throughs. For those that wish to use other cables we make a very high quality ZuB3 to Cardas
pure copper binding post adaptor. Users that own Zu loudspeaker cables which feature our
ZuB3 cable technology (Wax, Libtec, Ibis, Event) we will reterminate the cable free of charge so
performance can be maximized.
NOTE: We highly recommend factory termination. However, ZuB3 via Neutrik speakON
termination convention is outlined here for reference.
3+
2-
4+
2+
1-
1+
4-
3-
ZUB3™ VIA NEUTRIK® SPEAKON™ 8-POLE TERMINATION CONVENTION
Pin-outs for ZuB3 via Neutrik speakON 8-pole / single channel
SPEAKER + SPEAKER
–
SPEAKON 1+
SPEAKON 2–
SPEAKON 3–
SPEAKON 1–
SPEAKON 3+
SPEAKON 4–
UNUSED: 2+, 4+
SP+ 1+
SP+ 2–
SP+ 3–
SP– 1–
SP– 3+
SP– 4–
NEUTRIK 8-POLE SPEAKON CABLE-END CONNECTORS FEATURE POZIDRIV #1 SETSCREWS

DEFINITION MK.IV MAINTENANCE
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
MAINTENANCE & CLEANING
Unless specified otherwise by the purchaser—Zu Custom Shop finishes include hand rubbed
wood finishes—Zu finishes of all types are engineered for a lifetime of trouble free good looks.
Just wipe ‘em down whenever you feel the need. A lightly damp microfiber cloth or chamois
is recommended. Wood finishes are impregnated with a sealer and state-of-the-art conversion
varnish top coats and are highly water resistant but are not waterproof. You can use any
household wood finish cleaner / wax / polish you like, as well as the mentioned damp chamois
or microfiber cloth.
High gloss finishes do not need any additional UV or other protection and we do not recommend
wax. For serious cleaning and polishing we recommend 3M® Perfect-It™ 3000 Glaze Polish or
equivalent. All our painted finishes are top shelf, super durable, waterproof, and will remain so
for decades, even in direct sunlight.
Dusting of the 10” full-range drivers should only be done with hand-held compressed air as
used in photograph and sensitive electronics dusting. Or, if you are careful, you can use a
very soft brush or even your bare hand to dust the full-range driver—but I would stick to the
compressed air. And as for the tweeter, not much you can bungle there.
No maintenance needed on the ZuB3 input connector. The Neutrik contacts are silver plated
and recessed to prevent them from getting contaminated. They are also self cleaning through
the contacts wiping action.

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
ZU ECOLOGY
MATERIALS, ENVIRONMENTAL REGULATIONS & DISPOSAL
All parts used within Definition Mk.IV are 100% recyclable. They do not contain any toxic
material. Any Zu product or part may be sent back to Zu, free of charge, for proper re-
use or disposal. Zu Definition Mk.IV loudspeakers are RoHS compliant (European Union’s
Directive 2002/95/EC, Restrictions of Hazardous Substances), and therefore do not contain
any of the following substances: mercury (Hg), cadmium (Cd), hexavalent chromium (Cr6+),
polybrominated biphenyls (PBB), or polybrominated diphenyl ether (PBDE). Additionally, Zu
Definition Mk.IV loudspeakers do not contain beryllium (Be). They are classified as a lifetime
life-cycle product and will most likely be in service for well over 50 years.
ENVIRONMENTAL STATEMENT / HONEST ECOLOGY
We at Zu take pride in hard work, innovation, engineering and manufacturing know-how, and at
the end of it, an honest, well built, kick-ass product. We also love to get out and enjoy life and
embrace all that the world has to offer.
Zu is sincere in its search for real environmental, human and ecology-friendly manufacturing;
no fluffy feel-good bullshit, just the real deal; and not because of some great googly moogly
“climate change” geopolitical power play nonsense. It’s simple isn’t it? People like being healthy
and enjoying blue skies, green hills and wildlife. We keep our impact to a minimum because we
get out and enjoy nature and don’t want to muck it up.
Zu makes good stuff, products that last, things you can pass down to your kids and their kids,
stuff that isn’t going to end up in landfills. Want to make a difference? Do a little research on
your own before you fall for hype, support a cause, discriminate, or purchase a product. The
people driving and building Zu believe that manufacturers and users have equal responsibility
and an obligation to their respective communities. Users and producers must search for real
solutions and maximize their positive impact on family, community, nature, and technology.

DEFINITION MK.IV SUB-AMP SETTINGS
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
SUBWOOFER AMP SETTINGS (AS SHIPPED)
Recommended starting position for user adjustable filters:
VOLUME 9 4 o’clock
LOW-PASS 60 12 o’clock
PEQ GAIN 3 12 o’clock
PEQ FREQ. 35 12 o’clock
PHASE 0 7 o’clock
BYPASS / ACTIVE filter switch should be set to ‘ACTIVE’ (down)
PHASE 0˚ / 180˚ filter switch should be set to ‘0˚’ (down)
On the following page you can see the processed signal results of the above ‘as shipped’
settings—charted in red.
Blue traces are user filter minimum / maximum results, for reference.
DEFINITION Mk.IV [Rev. A] | Audio amplifier with Hypex UcD-400-V5 core | Designed and made by Zu Audio in Ogden, Utah—U.S.A.AC draw: 600 W max / 8 W idle / 50–60 Hz | Risk of electric shock — DO NOT OPEN RoHS
230 V
(5A Fuse)
Input Voltage
(10A Fuse)
115 V
( Fuse )
Active 0˚
Phase
180˚
Volume Low-pass Filter PEQ Gain dB PEQ Frequency Phase in Degrees
1
2
3
456
7
8
9
100 0
2.4 3.6
610
20
110
30
40
50 60 70
20
31 35 38
50
41
44
47
0 180
18
36
54
72 90 108
126
144
162
Bypass
Filters
ZuB3 loudspeaker input via Speakon 8-pole / Zu convention
ATTENTION — pinouts do not conform to Speakon convention
ZU AUDIO DEFINITION Mk.IV
Power On
Off

ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
DEFINITION MK.IV SUB-AMP SETTINGS
DEFINITION Mk.IV REV-A LOUDSPEAKER SUB-AMP FILTERS
low-pass filter @120Hz (maximum bandwidth)
low-pass filter @ 20Hz (minimum bandwidth)
PEQ +6 @ 20Hz
10 Hz 20 50 100 200 500 1k
dB
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
+2
+4
DEFINTION Mk.IV SUB-AMP FILTERS
DEFINITION Mk.IV REV-A LOUDSPEAKER SUB-AMP FILTERS
Filters set at factory position #1
10 Hz 20 50 100 200 500 1k
dB
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
+2
+4
DEFINTION Mk.IV SUB-AMP // FILTER POSSITION AS SHIPPED

DEFINITION MK.IV
ZU AUDIO | 3350 S. 1500 W. | OGDEN, UTAH — U.S.A. [DESIGNED AND MADE BY US] WWW.ZUAUDIO.COM
ZU AUDIO DEFINITION Mk.IV [REV-A] LOUDSPEAKER SYSTEM SPECIFICATIONS + INFORMATION
Description
Production
Dimensions H x W x D
Weight
Packaged
Bandwidth
Efficiency
Impedance
Group Delay
Acoustic Center
Horizontal Listening Window
Vertical Listening Window
Recommended Listening Distance
Recommended Connector
Accepted Connectors Via Adapter
Internal Cabling
Conventional Solid-State Or Tube Amp
Power Recommendations
Amplification Considerations
Component Tolerance
Tweeter Detail
High-Pass Detail
Full-range Driver Array Detail
Subwoofer System Detail
Subwoofer Amp Type
Subwoofer Amp Input Power
Subwoofer Amp Chassis
Subwoofer Amp User Adjustments
Cabinet
Spike / Feet Insert Thread
Included With Loudspeaker
Loudspeaker Options
Life Expectancy
Manufacturers Country Of Origin
Compliances of Directives
Warranty & Service
High-efficiency, high-output, floor standing loudspeaker featuring Zu’s nano-sanctified full-range high output driver, Zu-
Griewe electroacoustic technology, no crossover or filters on full-range driver, complemented by the massive Radian 850
based tweeter. Deep bass is managed through a down-firing Eminence LAB-12 based subwoofer assembly complete with
internal Hypex™ amplification and user adjustable filters.
October 2011—
49-1/16 x 12-3/4 x 12-3/4” [125 x 32.4 x 32.4cm] // footprint is 12.75” [32.4cm] square
150 pounds [68kg] // may vary with finish selection
FlexPak foam encapsulated 56 x 21 x 21” [142 x 54 x 54cm] 165 pounds [75kg]
14–20kHz
101 dB-SPL 1W, 1m
8Ω, nominal full bandwidth
< 5ms
36” [91cm] adjustable via footers and subtle canting of loudspeaker system
45˚
15˚
8 feet [2.5m] or more
ZuB3 via speakON 8-pole [ZuB3 convention single channel] Zu cable featuring ZuB3 cable technology recommended
1/4” fork spade [6.3mm], oversized 5/16” [8mm] fork spade, bare wire (banana plugs in a pinch)
ZuEventB3/Def4-A
1–4 watt (average room, moderate volume)
4–16 watt (large room, loud listening)
16–64 watt (large room, concert levels)
500 watt (maximum input power)
Definition Mk.IV is designed around conventional or parallel mode amps, bridged amplifiers are not recommended
(black speaker negative leg [sp–] of bridged amps will see the virtual ground node of the internal bass amp)
drivers 0.05% pair matching, 0.01% on electrical components
1x Radian 850 based dynamic tweeter // bandwidth: 12k–20kHz (high-pass bessel @ 18kHz)
1st order bessel @ 18kHz (12kHz acoustical) Mundorf Silver/Oil 1uF + Mills 10Ω12.5W Rs + 10Ω12.5W Rp
2x Zu103/ND/G1-16 nanotech full-range driver // bandwidth: 30–12kHz (direct and unfiltered)
1x Eminence LAB-12 based subwoofer, sealed // bandwidth: 12–80Hz (user adjustable, actively filtered)
internal Hypex UcD 400-V5 based, high energy toroidal transformer
115V (8A max) or 230V (4A max), 50/60Hz (transformer voltage rewire possible, inside case work) 8 watts @ idle
machined aluminum case work, rack style fitment allowing in the field service / replacement
Volume // Low-pass Filter Knee // Parametric EQ Gain // Parametric EQ Frequency // Phase
composite wood plate core; hardwood, aluminum and steel superstructure and stressed members
3/8–16 TPI, 9/16” hex nut, 14mm wrench can be used
4x hard press-on full-range driver covers, installed
8x hard surface stainless ball-end feet / 8x stainless 9/16” [14mm] jam nuts, installed
8x long carpet spikes, 1x connector cleaning kit, 1x finish cleaning cloth, 1x owners manual
ZuB3 via speakON 8-pole to Cardas patented binding posts, allowing any cable to be used,
grille, custom finish work
100 years; cabinet, and drivers, including the Zu 10” drivers; even in direct sunlight
U.S.A. all parts and labor excluding a few components. Hypex amp modules are made in the Netherlands
60065 | EMC 2004/108/EC | 2006/95/EC | 55103 | RoHS | CE | WEEE | Class-2 subwoofer amplifier
5 years limited on cabinet and drivers; 2 years limited on subwoofer amplification—warranty does not cover misuse,
abuse, components upstream from the loudspeaker system, modifications or non-factory service.
SPECIFICATIONS