Unity Audio Cerous Parm Brochure

Cerous

Professional Application

Reference Monitor

[PARM]

Introduction

Welcome to the world of the
Monitor. The Cerous

PARM

UNITY AUDIO

Cerous Professional Application Reference

System was the culmination of over 5 year

s of dedicated
research into the areas of Psychoacoustics, the study of how the human hearing
mechanism interprets sound, and the Physics of Wave Propagation by Transducer.
Listening biases can be argued and debated, but the Cerous

PARM

System is, without
question, the most technologically advanced loudspeaker system on the market today.
Employed are design principles never before realized in loudspeaker technology.

1] The worlds first fully Derivative Passive Crossover, which places no

co

mponents in the signal path

2] The world s first all Ceramic Composite Cone drive unit loudspeaker

Combined, these elements yield a system that is flat in both electrical and acoustic phase,
with the purest signal path ever incorporated in a production loudspeaker.

3] The

UNITY AUDIO Phase Locked Woofer System enabling the design of a
woofer system that, until its creation, had been labeled a physical
impossibility .

The creation of the passive BALANCED CLASS A CROSSOVER (curren

tly used in all
products) alone required a Cray supercomputer solving NODAL WINGS totaling 27
variables! The next advancement
added even more to the equation.

- The world s first fully derivative passive crossover-

Equally radical is the construction techniques employed to bring the Cerous
System to market. Each system is hand fabricated of composites of

FOUNTAINHEAD

PARM

and wood using propitiatory adhesive technologies and aeronautic cyanoacrylates
(SuperGlues).

We feel, however, that the most radical

area of the Cerous

PARM

System is HOW IT
SOUNDS! We hope you take as much pride in ownership of this revolutionary system as
we do in its production.

On behalf of all the people of

Robert L. Grost
President

UNITY AUDIO

we offer you ALL OUR BEST .

Unity Audio

Page 2

ELECTRONIC CROSSOVER

:

The electronic crossover is the electrical heart of the
In simplistic terms it is to divide the signal from the preamplifier into two separate
signals. The:

and send these signals to dedicated amplifiers to power the satellites and woofers. The
sonic transparency of the
signal path running to the satellites would cause an unacceptable sonic degradation. The
satellites, therefore, run full range and passively fall off in frequency below 65 Hz. The
subwoofers are added at 18 db/octave below 65 Hz by the fully balanced
Electronic crossover. All
configuration will stay balanced throughout the entire signal path never being converted
to single ended configurations for signal filtering and processing.

The configuration of the crossover is a buffered 3rd order passive low pass stage
followed by a gain stage with available 10 db of gain [to match levels between two
separate amplifier input sensitivities] and level control. The bass volume control is found
on the front of the crossover. The h

high pass] all frequencies sent to the Satellites
low pas

s ] all frequencies below 65 Hz (infinitely variable)

PARM

signals entering the Unity

, however, revealed that placing

igh pass circuit is a direct pass through element.

Hooking Up The Electronic Crossover

PARM

PARM

System.

crossover in the Balanced

ANY

device in the

PARM

Connect the output of the preamplifier to the jacks marked inputs being careful to make
sure individual channels are maintained. Traditionally if long interconnects are needed
they are placed between the preamp and crossover. This makes sense because you only
need

ONE

set of interconnects here versus
however, you are driving your system via a
player then the run of interconnects from the source to the crossover should be kept to
minimum length.

Connect the low and high pass output to the dedicated amplifiers. The
crossover will sound best after running for over 24 hours and should only be turned off if
no use is anticipated for an extended period of time. Utilizing
topology requires long warm up times to reach optimum temperature stability. Power to
the unit can be maintained while plugging in
stability.

The output of the high pass amplifier should connect to the satellites while the low pass
amplifier will connect the woofers.

TWO

sets from the output of the crossover. If,

PASSIVE

and removing interconnects with no loss of

preamp or directly

UNITY AUDIO

PURE

high bias

from a CD

CLASS A

Unity Audio

Page 3

Amplification Needs

The most requested information on proper system set up is the proper mating of the
Cerous
play. The ultimate design goal of the Unity Audio Cerous
totally reflect the other components of the system
own. What this means is that if you have tube electronics, your system will

THEIR SONIC CHARACTER
SHIFT

the problems associated with most tube amps - bass.

Many people have stated that you should only use identical amplifiers when bi-amping.
This is like saying that you can only build a dynamic speaker system

SAME DRIVER!

for each piece to function in
gain devices, yet, when asked to provide current fall far short of linear in nature.
Analyzing frequency spectrums we see that tube amplifiers deliver 75% of their current

BELOW 130Hz

solid state on the woofers. With this configuration tube amplifiers of 50 watt o
output will drive the system comfortably. Power requirements for the woofers are power,
power and more power [we recommend a minimum of 100 watts]. We also recommend
solid state on the bass. Each subwoofer is virtually unlimited in dynamic capability and
will sound better with the more power they receive. Each woofer cube is 3.5 ohms and
with a good 100 watt [8 ohms] solid state amplifier will play 115 db
higher output is needed add more power. Each woofer cube will handle 1

REMEMBER - there are some great sounding amps out there [both tube AND solid state].

Let the
technical assistance on amplification needs see the section on Cerous

PARM

. This can allow you to produce tube sound , if that is your preference, without

SOUND

System to amplification. It is here that individual taste will come in to

, while adding no sonic character of its

. If you use solid state,

The significant advantage to bi-amping is the ability to tailor the system

THEIR OPTIMAL MANNER

! For this reason many people choose to use tubes on the satellites and

tell you which one is best for you and keep an open mind. For further

:

PARM

the SONIC CHARACTER WILL

. Tubes are tremendous voltage

is a system that will

REFLECT

using ALL THE

r greater

ALL DAY LONG

800 watts!

PARM

technology.

. If

Speaker Placement

We believe that the Unity Audio Cerous
in the world to set up and position properly. Room boundaries, such as floors, walls, and
ceilings all reflect sound and affect bass loading . The first reflective surface the sound
encounters is the most significant with each subsequent reflection having less effect on
the sound than the one that preceded it. This is especially true in the region of bass. For
this reason we design the first reflection
satellite will encounter reflections off the pedestal of the speaker, while the subwoofers
will encounter the floor and top baffle. With this as an integral part of the design we
know

exactly
reflections were added into the design parameters. In essence
loudspeakers carry their own room around with them!

how the first boundary will

PARM

into each speaker

AFFECT OUR SOUND

Unity Audio

System is the easiest esoteric system

Page 4

! The rear woofer of the

. These boundary

UNITY AUDIO

With placement of the subwoofer 8 out from the front wall [wall to rear of cabinet] we
now know what our
design and

WILL NOT CHANGE FROM ROOM TO ROOM.

SECOND REFLECTION IS

! This reflection is also part of the

We can see that with the two most significant reflections as an integral part of the design
the room in

terface problems are greatly reduced. The only boundary that could now
effect the bass is the side wall. Placing our subwoofers farther away from our side walls
than 2x our distance from the front wall [2 feet] will virtually eliminate their effect on
bass performance. In addition, we recommend placing the subwoofers five feet apart and
between the two satellites.

The same design advantages used in the subwoofers are incorporated into the satellites to
aid in their room placement. With our first refle

ction set by the pedestal of the speaker,
we can see that the front wall will also be the second reflection for our satellite.
Placement 46 out from the front wall will give us the second reflection, and will begin
to cause phase cancellation at-- -- 65 Hz! This distance from the front wall will cause
the satellite s bass response to drop 12 db/octave starting at 65 Hz. For distances farther
than 46 out from the front wall the slope rate will remain linear. If the satellites are
placed closer to the

wall than 46 some mid-

bass reinforcement will occur. If this
situation occurs please consult your Unity Audio dealer or Unity Audio directly to
answer any questions you may have on system alternatives.

Begin listening with the satellites placed 9 feet apart [center to center] and toed in
slightly toward the listener. Start with the volume of the subwoofers turned all the way
down and slowly increase the volume until a smooth transition is achieved. After a rough
level match is accomplished turn the s

ubwoofers down in volume [approx. -3db] relative
to the satellites. If the system is fat sounding with too much mid bass [frequencies
between 130 and 350 Hz] increase the spread of the satellites farther apart from each
other

IN SMALL INCREMENTS

!

GO SLOW

. The mid bass will thin out until the proper
balance is reached. Conversely, if the system lacks mid-bass the satellites should be
moved closer together.

When the proper tonal harmonic neutrality is reached [the most frequent spread

AGAIN GO SLOWLY

.

is 9 feet
center to center] final adjustments involve proper aim or toe in . Select a piece of
music that contains a strong center image, such as a singer, with good surrounding
instruments. Being careful to maintain their room position turn the speakers so they aim
straight ahead pointing directly out into the room. Start the music.

SLOWLY

aim the
speakers more directly at your listening position only moving them a few degrees at a
time. The center image will lock into focus and the other instrumen

ts will maintain a
wide image spread. Continuing to toe in the speakers will compress the sound stage
while not improving the focus of the center image.

TAKE YOUR TIME

. Settle on the
best presentation with solid center focus and wide soundstaging. You will find the more
lively the room the more directly the satellites will point straight out into the room.
When proper positioning of the satellites is achieved you may now
volume of the subwoofers until proper volume is achieved. T

SLOWLY

bring up the

reating the spread of the

Unity Audio

Page 5

subwoofers as you did the satellites will also affect the mid-bass in much the same way.
If too much mid-bass is present, move the subwoofers wider apart in 1 foot [total]
increments until the system is properly tuned. You now have a properly functioning
Cerous

PARM

System.

TECHNICAL INFORMATION

The Subwoofers:

Each Unity Audio Cerous
Composite Ceramic Cones (C

PARM

Subwoofer contains two 12 woofers utilizing Cerous

4), rubber surrounds, cast frames, 3 voice coils and HUGE

vented magnet structures. Each woofer can handle bursts of 1800 watts and sustained
clean power of 400 watts for extended intervals. These woofers fire in direct motional
opposition to each other [when one is moving down the other will be moving up] so the
cabinet sees no change in the center of gravity. This aids to greatly reduce cabinet
vibration and motion.

The cabinet is constructed of laminations of solid Fountainhead, with no sections less
than 1 thick. The greatest mass is concentrated at

the cabinet center of gravity, which is
also the center of the cabinet. The center of each woofer cabinet is a solid laminate of
Fountainhead 14

THICK

! Cabinet construction is of space age cyanoacrylates that
bond at a molecular level. These adhesives are superior to other bonding agents because
they do not form an Impedance gap between the two pieces to be bonded. In simpler
terms, the two pieces will behave as if they were one piece molded together as one,
instead of two separate panels that are touching in one place. This is a key element of
the

PARM

cabinet structure, in that the entire cabinet behaves as

one structural element.

The last key to structural resonance control would reside in the ability to eliminate the
large air masses that occupied standard subwoofer systems. In acoustic structures
resonance s occur through two forms of excitation -

vibration and transmission.
Vibrations transmitted directly from the driver to the cabinet can be controlled by cabinet
rigidity and mass, but,

energy carried by the air mass that occupies the cabinet are
extremely random and hard to control. Focusing on this problem and treating this air
mass as a

ENERGY

transmission medium [

ENERGY

can not be created or destroyed] it
proved a monumental task to dissipate this energy in any practical fashion. Through
extensive computer modeling and mathematical analysis, a cabinet design was
formulated that
by which resonance is carried throughout a lou

DID NOT VARY WITH INTERNAL VOLUME

dspeaker cabinet could be effectively

!!! Therefore, the medium

eliminated. With no air mass inside to carry the sound around no resonance s could be
transmitted from one area of the cabinet to another. For this reason each Unity Audio
Cerous

PARM

Subwoofer contains minimal damping materials inside to absorb sound .
Small pieces of foam are employed to couple the woofer baskets to the cabinet sides for
damping of

VIBRATIONAL

resonance s.

Unity Audio

Page 6

The result is a subwoofer system that is -3 db down at 23 Hz [real world] with an
effic

iency of over 94 db 1 watt/ 1 meter with virtually no internal volume! These
subwoofers employ NO equalization or frequency contouring. The
subwoofer is now a reality. Each Cerous

PARM

subwoofer weighs 127 pounds each.

IMPOSSIBLE

The Satellites

The satellites share the same structural qualities as the Unity Audio Cerous

:

PARM

Subwoofers. Vibrational resonance s, however, are handled quite differently. Vibrations
at high frequencies were found to be an extremely important aspect of inner detailing
c

apabilities. If you look at a tweeter it must start and stop thousands of times a second
and any vibration of the cabinet will cause a loss and smearing of information. The
greatest cause of vibration to the tweeter is from the midrange transmitting vibrations to
the cabinet. Bracing alone proved to be ineffective as a cure to this problem.

Unity Audio took a radical approach to this problem. An identical driver [another
midrange] is mounted to the rear of the cabinet and operated in parallel with the

main
midrange. The position and mounting of this driver were fine tuned to transmit an
opposite vibration into the rear cabinet wall forming a vibrational null spot located in the
exact spot the tweeter is located. This is one reason why the high frequency performance
of the Cerous

PARM

is so dynamic and uncolored. This also leads the Cerous

PARM

to
be brutal to ANY shortcomings found in equipment or sources that precedes it [especially
those of digital artifacts].

The most radical feature of the Cerous PARM

loudspeaker cabinet is the engineering

address to how a loudspeaker cabinet dissipates energy. Research has shown that the

contradiction exists that the deadest cabinets see the most improvement from the
resonance control devices such as Combak dots and other control devices. This, on the
surface, is a contradiction, but after analyzation, we see that it makes great sense. If we
realize the

true

reason that our cabinet exists, we can see why this relationship occurs.

The enclosure exists to

dissipate the rear wave that is emmitted from the back side of the
cone. If a cabinet is totally rigid and dead then, by definition, it is not capable of
vibrating to dissipate energy. With this in mind, we must realize that the only way this
cabinet can absorb and dissipate the rear wave is through the materials (damping
materials) stuffed inside the box. This creates real problems.

An anechoic chambers is a large structure made to absorb all the sound from a
loudspeaker so it may be tested with no reflected sound from the environment. A
anechoic chamber designed to work properly to only 50 Hz must be the size of a football
stadium and filled with absorbative material. If we realize that a dynamic driver (such as
a midrange or woofer) puts out as much sound from the back of the cone as from the
front of the cone we can begin to see the contradiction. If we need a structure like an
anechoic chamber to absorb the front firing energy, then why do we feel we can absorb
the rear wave with a shoe box a

nd some foam? Clearly, we cannot.

Unity Audio

Page 7

The Cerous

PARM

enclosures are the first ever designed to fuction as the real reason for
an enclosure, that of an energy sink. The enclosure must draw the rear wave away from
the back of the driver and dissipate this energy, or it will be reflected by the enclosure
and come back out through the driver cone. The Cerous

PARM

enclosure functions in

precisely this way. The ribbed sides of the satellite enclosure act as vibrational

dampers , each a different width and, t

herefore, each operating over different frequency
spectrums. These side panel sinks function like heat sinks on power amplifiers,
serving to vibrate and dissipate the energy from within the enclosure.

A cabinet that serves to preserve the integrity of the signal generated by the drive units
would only be well served by the best of drive units. For this reason you will never find
a paper cone driver in any Unity Audio design. All drive units employed in the Cerous

PARM

employ the world s first all cera

mic cone drivers - Cerous Composite Ceramic
Cones (C4). For a detailed explanation of the advancements of these designs ask your
Unity Audio Dealer for the white paper dedicated to the technology behind this
breakthrough cone technology. For the first time dynamic drivers, utilizing C4 cones, are
capable of behaving as pistons throughout their entire operating range, delivering a
uniform flat frquency
the cabinet technology and C4 drivers emp
the final, and possibly the most important, piece of the puzzle.
The passive crossover...

and phase response

with virtually no unwanted resonances. With

loyed in the Cerous

PARM

we now come to

The Passive Crossover

:

Unity Audio has been a pioneer in the technology of loudspeaker crossover design for
many years. Unity Audio s radical Balanced Class A Crossover technology was the first
to address time constants (the time delay element of a circuit) in both the positive and

negative

traditional c

signal paths. From this research has come an even greater departure from

rossover theory

- The Unity Audio Passive Derivative Crossover.

This crossover technology allows, for the first time, that the functional employment of all
crossover functions can be carried out
passive device (capacitor, inductor) is nothing at all in the signal path.

The

Unity Audio Derivative Passive Crossover

outside of the signal path

functions identically (electronically) to a

! The best sounding

normal crossover. The key element of the Derivative Crossover is that during the
frequency band devid

ing of the signal

The PARM

Unity Audio

Page 8