Pure Reference Extreme MK II Loudspeakers
The Coincident Pure Reference Extreme Mk. II is a significant improvement over the original PRE model.
The PRE II is the least compromised commercial speaker system I have yet experienced, of any type and at any price. To be clear, with the majority of my recordings (both analogue and digital), and during the majority of the time, I prefer the PRE II to my previous "Ultimate Reference":
Finally, I always make an effort to avoid repeating myself, but I am not able to improve on the conclusion of my original PRE review (links above and below), so here it is, with some minor updates and edits:
"...I feel it is possible, and necessary, to condense the entirety of this review into two simple sentences, which are both personal observations and opinions:
- The Pure Reference Extreme Mk. II does more things 'right' than any other speaker I've heard (it's the most 'complete' or 'natural').
- The Pure Reference Extreme Mk. II also does less things 'wrong' than any other speaker I've heard (it's the most 'accurate')."
Coincident is excited to announce that 8 years after its introduction, the Pure Reference Extremes are undergoing an update of significant proportions. The improvements include the following:.
- All drivers and crossovers will be internally wired with our state of the art Statement cabling;
- The tweeter and midrange drivers will be improved to the latest versions of the Accuton ceramic
- The crossovers will be updated and improved with superior components with some parameters being
The sonic results include: greater sense of transparency and immediacy, more extension and air in the upper frequencies, more harmonic completeness in the mids, greater revelation of low level detail and ambient information, and enhancement of visceral punch and impact in the mid bass and bass and seamless coherency from top to bottom.
Although considered by many as the finest speaker available at any price and without question at its selling price, the latest version of the Pure Reference Extreme now advances to a new level of performance.
While the cost of the mods are substantial, the price increase will be offered on an introductory price at only $3000 US more per pair - $29,999 US /pr.
Pure Reference Extreme Monitor
For those who wish to separate the Monitor from the subwoofer, we offer
the Pure Reference Extreme Stands. They are constructed from the same
special MDF of all Coincident enclosures which provide for the highest
rigidity and minimal resonance. The base is 2 inches thick while the
center post is 4" x 6" and are finished in the same Ash veneer
as the speakers. Spikes are included. There is no speaker stand in
existence that is superior.
Price - $999 US/pr
Speaker Connection - The best method sonically is to
connect one pair of speaker cables from the subwoofers to the amp
and another speaker cable from the monitors to the amplifier. An
alternative method - Connect a speaker cable from the subwoofers to
the monitors and another speaker cable from the monitors or the
subwoofers to the amplifier.
Pure Reference Extreme
on optional Stand
The desire to create a breakthrough in any field of human endeavor must be fueled
by a burning passion to be the best. Coupled with this must include the
requisite expertise and the experience necessary to actually accomplish this
daunting task. Further add the endless hours of time and labor with the need for
boundless energy and the prospect of succeeding may nevertheless still prove
illusive. However, when all of the above ingredients coalesce and the goal is
attained, the result is the Coincident Speaker Technology Pure Reference Extreme
The Pure Reference Extreme is the culmination of a lifetime's devotion and
fanaticism with recreating the live musical experience in the home. This speaker
exists for only one purpose: to enhance the conveyance of the musical message to
a degree not experienced outside of a live concert. No expense and no effort
were spared and no detail was deemed too trivial in creating the Pure Reference
Extreme. The mission in bringing the Pure Reference Extreme to fruition was to
afford the music lover the opportunity to experience in his own environment the
most accurate musical reproduction possible with virtually any amplifier in
existence, from flea powered SETs to large solid state and everything in
between. The Pure Reference Extremes can be easily driven to concert hall levels
by low powered tube amplifiers (3 watts or more) because they possess the 5
requirements which make this possible:
1. High sensitivity (94 db @1m-1 w)
2. Uniform high impedance modulus (flat 8 ohms)
3. Total absence of any hard phase angles (meaning they are absolutely phase
4. Very tight bass tuning (which makes it easier for low damping factor- high
output impedance amplifiers like SETs to control the woofers).
5. Simple first order crossovers which do not rob amplifier power or reduce
Many audiophiles believe the most accurate amplifiers are single ended triode
tube designs, yet few speakers are capable of being properly driven by these
amps. This creates a paradox of sorts. Speakers need amplifiers to create sound,
yet the finest amplifiers cannot be used by virtually all the state of the art
speaker contenders. These speakers must then be mated to inferior sounding
amplifiers with resultant compromised sound. The Coincident solution is to
create the finest loudspeaker that can be optimally driven by the finest
amplifiers. The end result is the most accurate musical reproduction
To create a state of the art loudspeaker requires that every component used in
the design is the finest and that the sum of its parts are synergistically
matched so that the final product is a unified whole. Therefore, not only must
the design and concept of the speaker be state of the art, so too must the
execution. This means that all the ingredients which comprise a speaker must be
given equal attention with none being deemed less significant. Everything
ultimately affects the sound, no matter how seemingly trivial it may appear to
be. Everything used in the Pure Reference Extreme was thought out in
excruciating detail, tested and verified. From the less observable parts such as
mounting bolts, wiring length, and solder to the more obvious such as crossover
components, drivers and enclosure materials, nothing was left to chance. The
Pure Reference is state of the art in every conceivable manner.
1. Not only because they represent the finest currently available, but
because they conform optimally to the intended design.
2. Are very robust and reliable. They can handle tremendous amounts of power
with no sense of strain or fear of break down. Yet at the same they are highly
sensitive and require very little power to achieve high sound pressure
3. Have very wide bandwith and smooth roll off characteristics outside of their
respective optimum frequency range.
4. Possess very uniform impedance modulus.
All of the above listed factors mean that the crossovers used in the Pure
Reference Extreme can be exceptionally simple with only one component in the
signal path for each frequency section. Impedance correction components are not
even required, so smooth is the impedance curves. All this translates to
unrivalled purity and transparency.
The uniquely special qualities of the tweeter and particularly the midrange
driver, allowed for the first time, a state of the art, full range speaker using
only 2 drivers to cover the frequency range from 100hz – 27khz with the
midrange unit alone reproducing all the midrange frequencies. This meant no
crossovers or differing drive units with their own individual sonic signatures
involved in reproducing the highly crucial midrange. All the mid frequencies now
speak with one voice. This sense of cohesion is immediately apparent in contrast
to other competing speakers. Not only do all instruments not change character as
the frequency range is traversed, the precise localization of instruments in
space takes on a palpable realism that is spooky.
In order to reproduce all the upper frequencies with complete transparency,
transient speed and precision and simultaneously be capable of capturing all the
attendant harmonics necessitated the employment of a tweeter with ultra low
mass, extremely high cone rigidity and hardness. The driver that perfectly fits
this bill is the Accuton ceramic tweeter. The stiffness/weight ratio of this
tweeter is unsurpassed with the only exception being that company's diamond
diaphragm unit. There is no sound that can elude its very nimble grasp yet its
inherent strength permits its response to well beyond the limits of human
hearing. Furthermore, this special tweeter presents a purely resistive, totally
flat 8 ohm load with no dips, no peaks or spikes. Very high sensitivity is
partly due to the use of a powerful neodymium magnet structure. A very solid,
and acoustically inert faceplate ensures resonant free reproduction and the
elimination of diffraction affects.
This tweeter has proven to be nearly indestructible. It can be driven to high
SPLs with distortion artifacts that are vanishingly low. Furthermore, at low or
high levels, there is no change in sonic characteristics. The tweeter always
sounds detailed, smooth and refined.
The all important midrange is where the majority of the music emanates. No
speaker that aspires to state of the art status can be compromised in this vital
area of performance. To that end, what many would consider the purest driver
available for this task was chosen for the Pure Reference. The Accuton 6.5"
ceramic midrange proved to be the perfect choice on many levels. Firstly, it
happens to be the highest resolution, lowest coloration driver capable of flat
response from 100hz – 4khz. Secondly, since it is constructed using the
same cone material as the tweeter, no other driver could be as cohesive and
seamless. The combination of the tweeter and its companion midrange sound like
one driver operating from 100 hz – 25khz. The midrange unit features an
oversize neodymium magnet for very high sensitivity, a titanium voice coil
former and a double roll surround for complete linear motion. Terminals are
thick gauge, gold plated copper which ensures large contact area and a very
While this driver has very flat, even response from 70 Hz – 6000 Hz, it is
operated in the Pure Reference Extreme only from 110hz to 4 KHz. Therefore, the
midrange driver reproduces all the midrange frequencies (where the ear is most
sensitive to crossover and phase anomalies). Couple this to a tweeter that has
virtually the identical sonic characteristics and the end result is the
coherency of a single driver, crossoverless speaker.
The midrange driver is rolled off at the low end acoustically by the use of bass
tuning, ( the purest way to accomplish this) not electrically which would
require the addition of another component(a large value capacitor) in the signal
path This limited operating range ensures completely optimized response, highest
sensitivity and power handling capability and lowest distortion. Preventing the
driver from reproducing the bottom octaves relieves the midrange units from
unnecessary long cone excursions which increases upper frequency distortion.
The remarkable ceramic midrange's wide frequency response, high power handling
capability, high sensitivity and state of the art sonics all combine to allow
for the first time, the use of a single driver to reproduce all the midrange
frequencies in a reference loudspeaker. In the past, due to the inherent
limitations of conventional midrange transducers, multiple drivers were required
and they still had to be limited in response since they could not adequately
cover the range of frequencies from 100hz- 4khz. Coincident is a firm believer
that simple is always better when it is possible. The Accuton high sensitivity
version ceramic midrange, not only made it possible but does it better as
For state of the art reproduction, subwoofer bass that is seamless with the mids
and the highs is mandatory. Not only must the bass extend flat to 20 Hz, with
weight, authority and impact, the low frequencies must be articulate, tightly
tuned and never sound boomy, or out of balance with the rest of the frequency
spectrum. It is in the midbass and low bass where most speakers suffer badly
with comparison to live music. When attending a concert the visceral impact of
bass and midbass instruments (such as drums, double bass etc.) is awe inspiring.
The sense of weight and intensity can be heard as well as felt. This rarely if
ever happens when listening to music at home on an audio system. It is in this
area of performance, possibly more than any other, that home speakers fail to
measure up. The speakers that are relatively adept in this area are mostly
hopelessly inadequate everywhere else. Conversely, the speakers that are
transparent and truthful in the midrange and the highs most often do not at all
recreate the sense of drama and intensity in the low frequencies. Are these two
areas of performance mutually exclusive? For the overwhelming majority of
speakers, the answer is yes. There exist very few speakers that are smaller than
a mini van and cost less than a bungalow that can do it all. Until now, that is.
The Pure Reference Extreme is unique among speakers of reasonable size and cost,
that can with equal aplomb capture the sound of a pin dropping and realistically
recreate the furor of a cannon being shot.
How is this accomplished? It starts with an enclosure of the proper volume (the
laws of physics must be adhered to) and total rigidity and ends with the
selection of the finest woofers that money can buy that are specifically
designed for this purpose. The new 12" extra long stroke unit employed in
the Pure Reference Extreme has pushed the performance limits for subwoofers. The
construction standards are truly remarkable: Thick cast iron frame ensures
complete rigidity, heavy duty, stiff, aluminum cone that is almost impervious to
flexing, a magnet structure that weighs in excess of 15 lbs., thick gauge gold
plated copper terminals to maintain high current capability.
This driver fulfills every demand for deep bass (f3 is 17 Hz). With its unlimited
power handling capacity, 110 db levels at 20 Hz with virtually immeasurable
distortion and complete long term reliability, this new design accomplishes
state of the art bass reproduction that was previously not possible. While a
single driver will excite and please the most demanding bass aficionado, imagine
what two of these per speaker will accomplish. The Pure Reference Extreme uses a
pair of these remarkable subwoofers in each speaker. For the first time, live
music impact, punch, and genuine subwoofer bass with all the visceral excitement
experienced when attending a concert is a reality. Because the tuning of the
woofers is extremely tight, there is no concern about overloading a moderate
size room with excessive bass. The bottom octaves, for all their explosive
dynamic capability, are perfectly in balance with the midrange and the highs.
There is no accentuation of any frequency range. The Pure Reference Extreme is
beautifully balanced from top to bottom. Indeed, the speaker not only measures
virtually flat from 20Hz – 20 khz, it sounds that way as well.
The Pure Reference Extreme out of necessity, is a two enclosure structure in
order to create a state of the art design. The enclosure is a true case of form
following function and fulfills its mandate as a truly full range (20 Hz –
20Khz) state of the art transducer. This is a simple case of adhering to the
laws of physics. In order to achieve true, undistorted 20 Hz bass response, the
cabinet volume must be a predetermined size (and that means big). Constructing a
speaker of proportion this generous and have it be as non resonant and inert as
a small speaker, proved to be a monumental task. The challenge commences with
the selection of the base material- 1.15" MDF Hardwood which is veneered in
furniture grade Ash inside and out. The tweeter and the midranges are housed in
their own ported enclosure which contains computer designed window braces
horizontally placed between each driver. The woofers are mirror imaged side
mounted on a double MDF wall (2.3" thick) so that their massive cone
excursion capability would have a totally rigid foundation impervious to any
flexing. Computer designed window braces are horizontally located between and
vertically placed beside each woofer to further augment the integrity of the
enclosure. In fact, computer designed window braces are placed every 6"
within the enclosure to ensure that the cabinet is absolutely rigid. As with all
Coincident speaker enclosures, the fundamental resonance frequency is benignly
high (350 Hz).
All this effort, technology and innovative design and meticulous execution
results in an enclosure that does not contribute its own sonic signature to the
As with all Coincident speakers, first order crossovers (which are the purest and
preserve phase coherency) are used with only the finest components, matched to
within 1%, all hardwired with lead to lead construction (eschewing the use of
unnecessary wires or connectors). The signal path contains only one capacitor
(Mundorf – The most transparent cap for the purpose) and two inductors
(proprietary 10 AWG OFC Litz - one for the midrange and one for the bass). That
is it. Elegant simplicity but as Einstein remarked- not too simple. This
crossover is the most transparent, unobtrusive in existence. In bypass tests,
its presence is virtually undetectable.
The Pure Reference Extreme offers:
- Full range, breakthrough state of the art sound;
- Stunning aesthetics;
- The ability to be driven by any amplification including SET tube amps;
- Easy placement in rooms ranging from moderate to large with placement to
within 20" from the back wall if so desired;
- State of the art design and construction with lifetime reliability.
Frequency Response: 20hz- 27khz
Impedance: 8 ohms ( never dipping below 6 or going above 10
Sensitivity: 94 db @ 1M - 1 watt
Power Requirements: 3 watts- 500 watts
Dimensions: Monitor - 12" H x 13" W x 6"D - Sub Woofer- 33"H x
13"W x 24" D
Weight: Monitor- 28 lbs Sub Woofer- 175 lbs
Driver Compliment - Monitor- 1- 1.2 " Accuton Ceramic
1- 6.5 " Accuton Ceramic Midrange
|Sub Woofer - 2- 12 " Aluminum Cone Heavy