Get recording studio quality in your
home. The new 'MasterClass 2504' near field reference
monitors boldly define 'mastering-quality' sound for
the listener's immediate environment. Using modern acoustical
technology, they deliver audiophile performance to your
desktop or bookshelf. Sold in carefully-matched pairs,
they offer the ultimate in truthful stereo reproduction.
Our unique transducer design utilizes
a patented 'coplanar' driver, which reduces interference
between high and low frequencies. This eliminates timing
inaccuracies, resulting in precise instrument definition
and wide soundstage.
Each MasterClass 2504 speaker features
a carefully tuned bass-reflex cavity, full range 4'
transducer, musical cross-over circuit, wide frequency
range and 25 watts of power-handling capability. The
speakers are finished in black piano lacquer and look
great in any environment.
Our Coplanar-Coaxial technology makes sure that bass
frequencies, mid range frequencies and high frequencies all originate
from the same point in space. This is not possible with traditional 2-way
speakers, where the woofer and tweeter are located some distance away
from each other. The main difference between the CEntrance driver and
the traditional speaker design is extra clarity, precision and soundstage,
resulting from co-location of the two speaker drivers within the same
enclosure. CEntrance's unique Coplanar-Coaxial technology is described
in detail under the "Design Approach" tab. Click to learn more.
The innovative dual-coil driver behind the CEntrance
MasterClass 2504 speakers confines the woofer and the tweeter within
the same, shielded driver assembly. Mounting both drivers on a solid frame
allows precise alignment of the drivers' emanating planes and ensures
that all audio frequencies arriving at your ears come from the same spot
in space, not from several different places. The picture on the left shows
the driver assembly. You can see the tweeter connections at the top and
the woofer connections towards the bottom. Both moving coils use the same
magnet, a patented design. The CEntrance approach is the best possible
way of making the two drivers sound like one. The solid metal enclosure
further guarantees shielding from RF frequencies and results in clean
sound reproduction, free from unwanted interference.
Custom Crossover Network
The crossover circuit is at the heart of any dual-driver
loudspeaker. It splits the audio signal into dual frequency bands that
can be separately routed to the woofer and tweeter drivers. CEntrance
developed a custom passive design to minimize phase shift, frequency non-linearity
and resulting distortion. The audio-grade caps, oxygen-free copper in
the custom-designed, core-less coil and custom low-leakage PCB make our
crossover the reason MasterClass 2504 speakers sound so good.
Bass Reflex Port
The bass reflex port is an acoustic amplifier that uses
the sound from the rear side of the diaphragm to increase the efficiency
of the speaker at low frequencies. The CEntrance MasterClass 2504
speakers feature a carefully-tuned bass port that ads a boost to the lower
end of the frequency response allowing to make the overall enclosure smaller
without compromising bass performance. Proper adjustment of the cabinet
and port size and matching with driver characteristics results in a smaller
book-shelf speaker with audiophile performance.
CEntrance approached every little detail with highest
degree of attention. The feet on the bottom of the speakers are bolted
down, not glued, underscoring professional build quality. The feet contain
the right amount of firm, resilient foam and offer the perfect balance
of form and function. While allowing a necessary amount of cushioning,
they feature a solid grip. These speakers are gentle enough to not scratch
your book shelf or desktop surface yet they will not slide around during
Low-Impedance Binding Posts
The CEntrance MasterClass 2504 speakers feature
gold-plated binding posts located on the back panel for easy access. Gold
plating ensures freedom from corrosion and lowers the electrical impedance
of the connection. This guarantees freedom from signal loss and stable
operation for years to come.
Our binding posts accommodate standard banana plugs as
well as cable lugs. The connectors are clearly labeled in accordance with
industry-standard practices. The positive terminal is red and is located
on the right. The negative terminal is black, located on the left.
CEntrance uses the same binding posts on the DACmini
PX DAC/Amplifier, which is voiced and tuned to work together with MasterClass
2504 Speakers. Click here to learn about the attractive bundle, which
combines DACmini PX and MasterClass 2504 speakers.
25W per channel
4", full range, dual-driver, coplanar coaxial type
Neodimium, high-performance magnet
Passive, featuring audiophile capacitors
Solid wood consutruction (no particle board)
Mirror-polished piano laquer finish
Gold-plated posts for banana jacks or spade lugs
L: 207mm; W: 145mm; H: 230mm, each speaker
2.48kg, each speaker
L: 468mm; W: 217mm; H: 299mm, holds a stereo pair
CEntrance utilizes a unique approach in the design and
construction of its MasterClass 2504 speakers. Their sonic difference
is manifested in the precise localization of sound sources, great soundstage
and tremendous presence, despite the smaller formfactor. This is all due
to the innovative design of the speaker mechanism. Since the differences
in acoustic technology may not be obvious at first glance, we felt that
it was appropriate to spend a little time explaining the physical principles
behind our design approach and compare it to the more traditional speaker
manufacturing techniques. If this short tutorial doesn't make you a speaker
designer, at least it will make you an informed consumer of speaker technology.
That alone would make us very happy.
Why We Did What We Did
CEntrance is first and foremost an engineering firm.
We love a good design challenge. Back in 2000 we started out as a technology
provider to other manufacturers because we were driven by passion for
innovation and design. Nothing has changed, really. From that day forward,
for over 12 years we continue to be mostly about what's "under the
hood". When we develop a new product, we are not satisfied until
we arrive at a robust, technologically superior solution that offers a
sonic benefit like no other product.
Naturally, when we decided to offer high-quality loudspeakers
to go along with our DAC and amplifier products we were not satisfied
with bringing to market a "me too" solution that was fundamentally
the same as many other readily available products. We wanted to introduce
true innovation. We knew we were ready to release the MasterClass
2504 coplanar coaxial speakers when we truly had something special on
Standard Loudspeaker Design
For the remainder of the article, we will refer to the
word "driver" as it is used in the context of acoustics and
loudspeaker technology. Here it refers to an assembly consisting of a
magnet, a moving coil ("voice coil") and a diaphragm, the "engine"
that makes sound by moving the air back-and-forth in front of it. This
design is also known as a "dynamic driver", as opposed to the
Loudspeakers basically come in two varietiesthey
either have standard or coaxial location of drivers. The standard loudspeaker
features a woofer on the bottom and a tweeter at the top. This is the
most common arrangement in home stereo and bookshelf systems. We've all
seen them. These speakers are the cheapest to make because they rely on
simple driversseparate woofer and tweeter assemblies, each designed
to work with its own frequency range.
Fig. 1. Standard loudspeaker design features delayed
The problem with this approach is that the low frequencies
coming from the woofer and the high frequencies coming from the tweeter
originate from two different points in space. The sound waves have to
travel different distances to your ear and end up reaching you at different
times. This means that the resulting auditory "picture" is skewedit
is distorted, since you are not hearing things together. Some sounds are
delayed against the others. The larger the speaker, the worse it gets,
because the distance between the woofer and the tweeter increases and
with it increases the distortion due to arrival time differences between
the "highs" and the "lows".
The end result? Mushy sound with disappearing sound
stage, vague instrumental locations, and lack of that special feeling
of "being there". This is why traditional stereo speakers will
always have a hard time achieving truthful reproduction of complex music
Coaxial Driver Design
A coaxial loudspeaker is an attempt to solve the problem
of delayed arrival. The coaxial design locates the tweeter on the same
axis as the woofer, hence the name "co-axial". Typically the
tweeter is mounted on a bracket in front of the woofer, partially obscuring
it. This design is frequently found in car audio systems, where space
is at a premium. The coaxial speaker is shown on the diagram below. Click
images for larger versions.
Fig. 2. Cut-away 3D model of the Coaxial driver
While the coaxial driver solves one problem it introduces
another. The woofer and tweeter are located on the same axis, but on two
different points on that axis. They are located on different planes, as
referenced by the front panel of the loudspeaker. The tweeter is mounted
closer to the listener and therefore the high frequencies reach the listener
fasterthey have about 1 inch less distance to travel. Now, 1 inch
of distance may not sound like much, but it translates to the wavelength
of 13.5kHz, which is not only a perfectly audible range, but also a large
source of spatial cues due to echoes and reflections, which we rely on
in this area to determine instrument locations.
The end result? Poor source localization and uncertain
soundstage. What works for car stereos, does not work for audiophile systems.
Compact - yes, good sounding - no.
Coplanar Driver Design
Enter the concept of the Coplanar driver, the best representation
of a "single point source". The figure below shows that a coplanar
driver not only places the woofer and tweeter on the same axis, but also
locates their working surfaces on the same plane (hence the name "co-planar").
This means that high, low and mid frequencies are all reaching the listener
at the same time. With a coplanar design, the arrival times are the same.
Fig. 3. Cut-away 3D model of the coplanar driver
The two figures below illustrate the concept of delayed
arrival for the low frequencies compared to the high frequencies in the
coaxial speaker driver. Delta t represents the delay in arrival time.
The higher the delay, the more distortion at the listening position.
Fig. 4. Coaxial driver delivers high frequencies earlier
Fig. 5. Coplanar driver delivers all frequencies at once
So why hasn't coplanar technology, which is clearly superior
from the sonic standpoint, found greater popularity in speaker designs?
The answer lies in the complexity of such driver. It's actually quite
difficult to design a woofer/tweeter in one package. The CEntrance MasterClass
2504 speakers achieve just that goal. The combined driver in our speakers
features two voice coils, which are driven by the same magnet and located
practically on the same plane. It took many years of research to develop
a driver that accommodates both voice coils on the same frame and drives
them off the same magnet. The end result? The CEntrance MasterClass
2504 speakers redefine audio fidelity in a small package.
Fig. 6. CEntrance located the tweeter inside the woofer
for maximum linearity and lowest distortion
Fig. 7. CEntrance driver combines woofer and tweeter
in the same package
Congratulations for reading this far! Now you are an
expert and the last thing that remains is explaining the name choice.
We named these speakers MasterClass for a reason. In the 70s and
80's Recording and Mastering engineers started using coaxial speakers
in studios and mastering facilities to achieve the purest reproduction
of recorded sound. Their sound systems needed to be a notch above the
best playback system money could buy. Back then, things were different
and audio quality was very expensive. Today it's possible to build a mastering-quality
system in a home studio.
The CEntrance MasterClass speakers offer a breakthrough
in acoustic design. We are very proud of this technology and know that
you will be amazed with the clarity, localization, soundstage and overall
fidelity of these speakers.
One important note about using the MasterClass
2504 speakers in real homes: They truly open up if they are positioned
in such a way that there is no horizontal surface right in front of them.
One way to avoid the surface of the desk from interfering with the sound
is to place the speakers at the edge of the desk, the one closest you,
so that there is some open air right in front of the grills. If that's
not practical, the other option is to raise the speakers above the surface
of the desk on stands.
There is a lot to be said about speaker stands that "remove"
a nearby surface. This gets rid of unwanted reflections and allows the
soundstage to truly shine. With co-planar drivers such as these, that's
very important as the difference is huge. Because of the ported enclosure,
also try to maintain at least a foot of open air between the speakers
and the wall. Same reason herereflections kill clarity.
Michael Goodman, Chief Product Architect
"For nearfield listening, I think CEntrances
MasterClass 2504s are tough to beat; in fact, they are among the
most sophisticated and satisfying desktop monitors".
"With the MasterClass(tm) 2504,
theres a sense of enjoying gain (natural neutrality) without
pain (an overly clinical sound), which is an appealing combination
of virtues... Its the CEntrance speakers ability
to go 3D on command (when recordings permit) that gives
the 2504 a real touch of greatness.
Imaging and soundstaging together become this
speakers crowning achievements. Few desktop speakers manage
to unfold into full-fledged audiophile-grade three-dimensionality
or to deliver the kind of precisely focused imaging the 2504 provides.
On good recordings, the MasterClass speakers produce soundstages
whose width extends well beyond the outer edges of the speaker cabinets,
and whose depth extends far behind the speakers (and sometimes far
behind the rear wall of the listening room). As you listen, then,
you become less and less conscious of the speakers, and increasingly
focused on whatever happens to be unfolding within the soundstage.
This is the real magic of the 2504sthe quality that
makes them different from and better than many of their competitors.
You may find these to be some of the most
satisfying, well-rounded, and impressively three-dimensional small
"Paired with the MasterClass coplanar
speakers, the DACmini PX excels at creating an incredibly textured
and defined soundstage. The expansion and articulation of the soundstage
is immediately palpable. Tonal accuracy and seamless control throughout
the frequency range also characterize the MasterClass speakers,
a finding wholly appropriate to a company keenly familiar with the
attributes of fine studio monitors.
Summary: For anyone looking for a high level
computer audio desktop system that is well built and delivers a
true audiophile experience, then the Audiophile Desktop is certainly
a great way to make it so."