PRESENTS
dARTS
DIGITAL AUDIO REFERENCE THEATER SYSTEM
ENTERTAINMENT WITHOUT BOUNDARIES
© 2007
WHAT IS THE PROBLEM?
For many hundreds of years, even back to the days of Bach, engineers, architects and performers have known that the most
important contributing factors to the sound of music or theater in a room have been the acoustic properties of the room
itself. Each dimension of a room (height, width, depth) creates room modes at many different frequencies that interact with
the room in very different ways, depending on where one is sitting or standing. Thus, every room contributes its own sonic
signature to the music by altering the content at all frequencies as they are played. Room acoustics also affect sound
reproduction by the amount of reflection and absorption they cause at various points within the room.
Loudspeakers interact with their environment − just as an orchestra does − and play a major role in how much we enjoy our
entertainment at home. Our homes are typically not designed to be marvels of acoustic engineering, like a fine concert hall.
Speakers are frequently placed wherever they happen to fit into the décor, without any thought given to how that
placement will react sonically with the room. The room’s many modes come into play. Standing waves and dips wreak
havoc with uniform bass response throughout the listening area, and walls and furnishings create major reflections and
absorptions to destroy the focus, clarity and detail of the sound. Because few of us have dedicated, purpose-built listening
rooms, the needs of daily life in our homes usually dictate that “state of the decor beats state of the art.”
It is well known that the speaker is the weakest link in any entertainment system. Modern amplifiers, preamps and source
components have reduced their distortion levels to a vanishingly low point and can be made to operate in a very linear
fashion. Speakers, however, are still a combination of imprecise mechanical parts and passive electrical components that
contribute significant distortion to the audio signal.
Speaker drivers − woofers, midranges and tweeters − react to the input signal, moving at many different speeds to
reproduce the entire audible spectrum. Each individual driver has an incredibly difficult job to do, and even the very best
raw speaker drivers won’t necessarily work well together. When we try to match them to each other to create a full-range
speaker system, it’s amazing that they work as well as they do. Production tolerances are difficult to maintain between
drivers, causing a lack of consistency in production of speakers. It’s rare to see drivers within an individual speaker matched
to within +/- 2 dB, much less between two or more finished speakers. Couple that with the many ways a speaker interacts
with the room environment, based on how it’s placed, and it becomes a seemingly impossible task to create really lifelike
sound reproduction. It is all a matter of optimizing compromises, and since the speaker’s designer has no idea how the
speaker will be used, there is no way to assure any sort of predictable response from a passive speaker system in a room.
The crossover network has the task of separating the various frequency bands and sending them to the appropriate
speaker driver, hopefully within each driver’s linear range of operation. The crossover also tells each driver how to move in
relation to each other, which is particularly critical in the regions where the crossover point between drivers overlaps. The
electronic components in the crossover network change their electrical characteristics as they warm up and cool down, they
change as they try to deal with loud signals which can saturate them, and they react differently as the drivers present a
constantly changing impedance load based on frequency. Even using components with very close tolerances does not mean
that they will react the same way to both heat and widely varying signal levels. Thus, a speaker system’s crossover first
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takes apart the input signal electronically, and then the speaker’s drivers need to put it back together mechanically and
acoustically, including the interface with the room itself.
Now, let’s suppose you’ve found speakers you really like. You take them home and hook them up, but there’s still no
guarantee they’ll sound good in your room.
• Are the vertical and horizontal dispersion characteristics of the speakers appropriate to your equipment location
and the room’s seating?
• Can you get a good enveloping soundfield at more than one or two seating positions?
• Does the sound change as you stand up or sit down or move from side to side?
• Are the speakers placed so that the sound from each arrives at your ears at exactly the same instant?
• Do the room’s furnishings and surfaces impact each speaker’s output the same way?
• Are all of your speakers voiced to sound absolutely identical (necessary to provide seamless blending of both the
front soundstage and the surround soundfield)?
• Are your speakers properly matched to your amplifier so they can provide proper damping to control the motion
of the drivers?
• Does your amplifier have sufficient power to produce undistorted peaks in all of your speakers, regardless of the
program material?
• Do your speakers have sufficient power handling to safely utilize that amplifier’s power on sudden peaks?
• Will the speakers handle that power without subtly overloading and compressing the peaks, yielding unrealistic
sound?
• How will your subwoofer react with the room’s acoustics if you can’t place it where physics dictates is the “proper”
location?
• How will your subwoofer blend with your other speakers?
These are just some of the questions that need to be answered to produce a realistic representation of music or movies in
the home or studio. It sounds pretty daunting, doesn’t it?
WHAT IS THE SOLUTION?
If we can’t just buy excellent products and install them into a room, expecting good results, what can be done? The
professional audio world has known for years that a big part of the solution is to use active speakers, meaning that the
speakers are coupled with amplifiers designed and equalized to complement the response of the speakers. This results in a
synergistic whole much greater than the sum of unknown parts. Professional recording studios, theaters and concert halls
have long done sophisticated measuring and modeling of the room’s acoustic properties and dimensions and have then
spent many tens or even hundreds of thousands of dollars adding treatments to precisely control reflections, reverberation
and bass energy. How often can we do that in our homes? How often does even a dedicated media room include all of the
treatments needed to remedy its inherent acoustic properties? Even if it is treated, which can still cost tens of thousands of
dollars, we know speakers and amplifiers vary widely in their responses to the constantly changing program material.
What can be done to assure hearing every detail in every soundtrack and musical recording just as the artists intended?
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The most elegant solution available is to design an entire purpose-built system from the ground up, allowing speaker
design, amplifier design, and room acoustic measurement and correction parameters to all work together as a seamless
whole. This allows all speakers to be matched to each other in frequency response, dispersion and sensitivity, theoretically
yielding a perfect blend as sound moves from one channel to another. Each speaker driver can be specifically engineered
to do exactly what’s needed instead of relying on a “one size fits all” approach. The multi-channel amplifiers can be
designed to precisely meet the needs of the speakers, with the proper amount of power applied to each individual driver
and frequency contouring to offset the natural response of each. The subwoofer can be designed to provide not only
ample output but also to match the speed and articulation of the other speakers and blend perfectly as it crosses over.
All of the system crossover functions and setup parameters can then be done totally in the digital domain. If there are no
passive components in the signal path, there is nothing to change or degrade with time, heat or operating influences. There
will be no interaction between the speaker drivers and their crossover beyond receiving the appropriate frequencies at the
proper times. Each driver can be made to operate only in its most linear region for lowest distortion and most accurate
sound, having very little overlap with other drivers. This results in a seamless blend throughout the frequency range,
ensuring great sonic detail and clarity.
Very powerful digital room analysis and correction software previously available only at the top end of the professional
industry is now available for home entertainment systems. Several surround sound receivers and processors now include a
rudimentary version used for automatic setup. These programs let you plug in an inexpensive microphone, run a series of
test tones, and automatically set the distance from each speaker to the primary seating location. Many of them also include
basic equalization for low bass frequencies to help correct for room resonant mode problems, which are peaks and valleys
in its response caused by the subwoofer’s location and the way it interacts with the room’s boundaries and dimensions.
In a full-blown implementation of digital control and calibration, levels between speakers can be matched to a much finer
degree than with a basic sound pressure level meter and analog volume controls. The room’s acoustics can be measured at
many points − all seating positions, different heights − and then averaged and weighted to provide uniform dispersion and
frequency response for every listener, no matter where he’s seated. Based on extensive research and listening, a variety of
frequency response target curves can be implemented and actually matched in the room to within very close tolerances. All
in all, the room can now become simply a passive environment, rather than an active participant in affecting nearly every
performance parameter. A listener is left with the music or the soundtrack as it was produced, played back accurately
without the system or the room adding to or detracting from the entertainment experience.
WHO IS THE SOLUTION?
Phase Technology of Jacksonville, Fla., has developed a unique, groundbreaking application combining several state of the
art technologies to produce an audio system which sounds its very best regardless of the room in which it is installed.
Working closely with two other highly respected American manufacturers, D2Audio and Audyssey Laboratories, Phase
Technology has engineered a music and theater sound system with stunning performance. Whether the room is large or
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small and whether your needs are for stereo reproduction or any of the many surround sound implementations, Phase
Technology’s Digital Audio Reference Theater System (dARTS) can provide a solution. The system is available in several
different form factors to accommodate virtually any room’s aesthetics and installation challenges.
Phase Technology is a division of United Speaker Systems, an American OEM manufacturer of quality speakers since 1955.
As a name brand, Phase Technology dates from the early 1980s and has always had a reputation for engineering and
building exceptional speakers. Many of the basic patented technologies in the loudspeaker industry were developed by
Phase Technology’s founder, including the soft-dome tweeter and the manufacturing process for flat-piston drivers. Even
after more than 50 years, Phase Technology is still a vertically-integrated manufacturer, engineering and building its own
speaker drivers, crossovers and cabinets. This commitment to in-house production in the United States yields superior
construction and superb quality control at all levels of the manufacturing process. The payoff from this is evident by Phase
Technology being consistently rated as one of the best suppliers in the audio-video industry for the past nine years, as
voted on by the nation’s dealers and published annually by the trade journal Inside Track. In their 2004 survey, published in
January 2005, Phase Technology garnered five first-place votes out of the 15 categories available for rating.
Once Phase Tech began researching the feasibility of developing a completely integrated audio system, they began
discussions with D2Audio of Austin, Texas. D2Audio is the leader in development and production of digital amplifier
modules for many applications. Phase Technology worked in concert with D2Audio to custom-design a specific amplifier
module for dARTS, matched to their speaker drivers. Conventional analog amplifiers have gotten very good over the
years, but they still change the signals by adding or losing information, creating distortion. This happens because they do
not react quickly enough to the constantly changing demands of the program source. Digital amplifiers, on the other hand,
are much faster in their response times. Think of the difference between standard analog television and what we see now in
digital and HDTV. There is so much more information being processed and sent to the screen that the resolution and detail,
the life-like recreation of images, and the depth and dimensionality of the picture is immediately apparent to everyone. So
can it be with digital audio amplifiers. If they are designed properly with accurate tracking of the input signals and
effective filtering of the output to the speakers, the amplifiers can dramatically improve sound quality over what we’ve
become accustomed to for the past century.
No matter how well the amplifier/speaker package can be made to perform on a laboratory test bench or in an anechoic
chamber, it is ultimately limited by the interactions with the room in which it is placed. Knowing what was being done in the
professional audio and music world, Phase Technology contacted Audyssey Laboratories in Los Angeles, a spin-off of the
University of Southern California’s Immersive Audio Lab, founded in 1996 by Tom Holman, inventor of THX and Professor
of Film Sound at USC, and Chris Kyriakakis, a Professor in the USC Viterbi School of Engineering. The company was born
when Tom and Chris came together to create a system that more easily calibrates and equalizes theaters. Chris was
looking for a difficult project to tackle for his tenure at the university, and Tom challenged Chris to develop a system that
was not only better than existing methods but also performed these functions automatically.
After surveying all the existing room equalization technologies available at the time, Tom and Chris combined their
expertise in room acoustics, psychoacoustics and audio signal processing to develop the framework that would ultimately
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lead to a revolutionary solution to the problem. The multi-year research commitment required to develop this framework
was undertaken by Sunil Bharitkar, a USC doctoral student, who used a very novel signal processing approach to solve the
problem. The algorithms were then developed into the many thousands of lines of DSP code that were required to
productize the technology.
Audyssey Laboratories’ first product is Audyssey MultEQ XT, an innovative set of patent-pending technologies that address
the numerous problems of calibration and room acoustical correction in the home, automotive and professional audio
markets.
WHAT DO WE OFFER AS THE SOLUTION?
The most audible and visible part of any entertainment system is the speakers. Every home and every room have different
parameters for successfully integrating multiple speakers into their layout, both aesthetically and practically. Phase
Technology recognized this fact and decided to offer high-performance speakers in several modular configurations to
integrate with the digital system, meeting nearly any listener’s need. Some media rooms include a front wall of cabinetry or
a perforated projection screen and require speakers to be built in and hidden. Some clients would like to have their main
speakers exposed to make a strong visual statement. Others want everything to be flush mounted into the walls and
painted over, so as to be nearly invisible. Some locations for surround speakers may not be built with framing to
accommodate in-wall speakers, necessitating surface-mounting versions, and both types need to be able to address the
directional versus non-directional surround issue. Phase Technology anticipated these needs and has designed a complete
line of application-based solutions to answer the age-old question of “What do we do with all these speakers?”
Phase Technology has developed a series of six different systems based on the dARTS technology. There are two basic
sizes, based on either 5-1/4” or 6-1/2” woofers, sharing identical sonic properties, with the only difference being in output
level.
There is a series of “black box” speakers to be hidden in cabinets or behind screens. This custom built-in series will offer the
highest output level of the various speakers, as most dedicated theaters will use hidden speakers. Each front speaker
features two drivers to handle the bass and midrange, with a 1” soft dome tweeter for the high frequencies, surrounded by
Phase Technology’s signature Unicell Acoustic Treatment™ to eliminate diffraction effects of the cabinet on the tweeter. The
woofers are made of a three-layer composite of a honeycomb aircraft core, surrounded by crystalline woven glass and
finished with a butyl rubber surround. This lightweight yet very strong material reacts with lightning speed to all the nuances
in the music and movie soundtracks and is one of the few materials which can keep up with the incredible speed of the
digital amplifiers. There is a matching powered subwoofer featuring two of Phase Technology’s acclaimed 10” long-throw
drivers, each coupled to their own 250-watt amplifier, for a total of 500 watts per cabinet. The subwoofer’s cabinet is the
same width as the front speaker, so it can be used as a stand if the need arises. There is also a smaller subwoofer cabinet
available containing an active 12” woofer with two 10” bass radiators, utilizing the same 500-watt amplifier. Surround
speakers can either be additional main speakers or a unique bipole/dipole speaker, which can be mounted either on the
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wall or flush in the wall in an accessory frame. It can be switched to operate as either a dipolar speaker for a very diffuse
and enveloping surround experience when placed properly in relation to the seating area or as a bipolar speaker for a
more localized and focused soundfield.
We also offer a complete line of highly stylized free-standing speakers in each size to impress even the most discriminating
tastes. They feature soft curves and sloping surfaces, inlays of extruded aluminum and beautiful veneers. The elegant main
speakers include one of the woofers from the custom built-in version and the same Phase Technology soft dome tweeter.
There is a three-way center channel speaker for horizontal placement above or below the display. Surround speakers can
be either the on-wall or in-wall versions shared with the other dARTS systems. A stunning lacquered free-standing
subwoofer comes with a 12” woofer and dual 10” bass radiators and a 500-watt amplifier. This subwoofer looks just as
good as it sounds. As in the custom built-in versions, these cabinets are made from very heavy, dense material and are
internally braced to avoid cabinet vibration.
Custom Built 6.5 FS LR Cherry Custom Built 5.25 FS LR Gloss Piano Black
The free-standing cabinets of the front and center channel models are available standard in either natural cherry or gloss
black. To further meet your needs for matching your environment, the 6-1/2” series (FS650) is available in virtually any
wood veneer or painted finish you choose. Naturally there is an upcharge for these custom finishes, but the system can
perfectly reflect your taste.
The final iteration of the speaker system is an in-wall version. These very high-performance, flush-mounted speakers mirror
the custom enclosure models, using the same drivers. They each include their own dedicated, damped, in-wall enclosure,
utilizing Phase Technology’s patented Positive Clamping System to assure optimal performance regardless of the wall’s
construction. The clamping system also minimizes speaker vibration that would normally excite wall surfaces and create
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either distortion in the listening room or intrusive noise in the adjacent room behind the speakers. If a listener chooses to use
multi-polar surrounds, the same in-wall/on-wall, bipolar/ dipolar speaker mentioned above is available. If the listener
prefers a directional surround speaker, he will install more of the main front channel in-wall models. Subwoofer choices will
include either of the free-standing, 10” or 12” versions mentioned above.
The greatest benefit of offering all of these options is that a client can work with his designer and his A/V integrator to
install a world-class music or theater system to fit in nearly any room configuration. All models are designed using the same
drivers and are voiced identically; so they can be used interchangeably in any position in the system, no matter if that
system is stereo, 5.1-channel, 6.1-channel, 7.1-channel, or any other future format. If more bass impact is needed, multiple
subwoofers can be used. Systems can be stacked to provide adequate volume levels in even very large spaces. Phase
Technology will even work with clients and their A/V installer to design custom systems with larger speakers and custom-
designed software to match. Add to that the unmatched digital processing power of the amplifier’s setup modes and the
optional Audyssey MultEQ XT room calibration package, and you’ll see that stunning realism, involving effects, and
dynamic power are assured in any listening environment. Never before has this much effort been expended to produce a
simple yet highly advanced entertainment system, of which the whole is so much greater than the sum of its parts and is
many orders of magnitude beyond the traditional methods of system design.
HOW DOES IT WORK?
Phase Technology and its partners, D2Audio and Audyssey Laboratories, have come up with an innovative solution to the
dilemma of making everything work as a synergistic whole in any environment. The heart of this breakthrough is the multi-
channel amplifier and processor, which manages the entire system and all of its parameters.
The Phase Technology DP-2000 was custom-designed and tailored for our speakers in collaboration with D2Audio. The
amplifier offers sixteen channels of power with up to 250 watts per channel for complete flexibility, whether the speaker
needs to be biamped or triamped. By driving each driver with its own amplifier, complete control is achieved with no
passive circuitry in the entire signal path, and the driver and amplifier are each free to perform at their very highest
possible level. Volume levels to balance drivers within a speaker are adjustable to within incredibly small tolerances (+/-
0.1dB) for a perfect blend. The crossover parameters for each driver can be precisely specified so that each driver works
only in its most linear range. Completely flexible equalization is available at any frequency to provide an inverse curve to
the speaker driver’s inherent output, yielding flat response for the entire system. Sophisticated phase- and time-alignment is
also possible in the digital domain, making practical the ability to match drivers to each other in a variety of cabinets to
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suit a variety of purposes. This incredible level of precision in matching drivers within speakers, and complete speakers
within systems, has been completely impossible until now; and Phase Technology is the first supplier to offer it to the
consumer market.
Once a client orders a Digital Audio Reference Theater System with his choice of speaker styles for each channel, the
system will be calibrated and shipped to the installing dealer. Remembering our discussions of the laws of acoustics, even a
perfectly matched system such as this will perform differently in different rooms. The Audyssey MultEQ XT technology,
customized for Phase Technology’s digital system, offers installers the industry’s most advanced room correction tool, giving
the system lifelike and precise sound output in its environment. It addresses all of the problem areas of the speaker/room
interface with extremely powerful processing. Audyssey MultEQ XT is the first technology to automatically correct inherent
room acoustic problems for multiple listeners. Other equalizers and room correction tools can sometimes achieve small
improvements in sound at one listening position - usually at the expense of the rest of the room - or treat every seat the
same, resulting in worse sound everywhere in the room.
To use the Audyssey MultEQ XT system, the installer will connect a calibrated instrumentation microphone to a high quality
multi-channel digital audio interface and power supply. The output from the digital interface will connect to a FireWire
port on the installer’s laptop and to the inputs of the DP-2000 amplifier. The computer will also be connected to the DP-
2000 via a USB cable. A series of test tones will be generated through the system, from which Audyssey MultEQ XT does
the following: (1) automatically measures the speakers’ and room’s contribution to the sound, (2) tells the installer where to
set the individual channel delays and levels in the client’s surround processor, (3) corrects any anomalies, and (4) creates
the necessary room correction filters, which match the sound to a carefully selected frequency response curve that is most
appropriate for the room’s size and characteristics. Installers can further tailor the system to an individual room by inputting
information about the room’s size and reverberation characteristics.
When the Audyssey MultEQ XT process is applied to a system in a room, it determines what each speaker is doing as it
interacts with the room and delivers sound to individual locations. It first looks at absolute phase to ensure that all speakers
are wired correctly, which is especially useful for in-wall installations. The system can accurately determine both a positive
wave front and the distance from each speaker to the initial prime seating location’s measuring point (for setting delays).
The distance is accurate down to less than one inch (typically 1/2”). The system then uses that measurement as a baseline to
align the other speakers’ time delay down to the same degree of precision, including the subwoofer, so that all sounds from
all speakers arrive at the listeners’ ears simultaneously. Once exact acoustical distances and phase are set, Audyssey
MultEQ XT will precisely calculate volume (balance) trim levels for each channel.
Audyssey MultEQ XT will next look at the frequency response of the system in the room - based on input from all selected
microphone measurement positions - and design a set of inverse acoustical correction filters to apply to the amplifier’s
outputs to the speakers. When traditional equalization methods are used to correct room responses, whether graphic (fixed
frequencies) or parametric (variable frequencies), they typically employ infinite impulse response (IIR) filters. These can only
deal with variations in the amplitude response. These types of filters introduce audible artifacts in the time domain that can
degrade sound. Furthermore, since these equalization schemes can only deal with one room location, they make sound at
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other locations worse than it was before the correction was applied. Phase Technology’s application of Audyssey MultEQ
XT provides 512 FIR coefficients per amplifier channel that provide the highest possible resolution in the lower frequencies,
at which room problems are most influential. It achieves this extremely fine resolution by applying principles of
psychoacoustics to non-uniform frequency mapping.
Now we’ve equalized the speakers and the room to sound perfect at the “sweet spot,” the primary listening location. What
about everybody else gathered to watch that blockbuster movie or special event on TV? How is it possible for a group of
speakers in different locations to interface with the room’s acoustics in their different ways and still provide uniform
response throughout the listening area? By measuring the test patterns at each listening location and at multiple heights to
measure both vertical and horizontal bass modes, Audyssey MultEQ XT begins to recognize response patterns in the room.
It then uses a fuzzy-logic based clustering approach to weight and combine the response at each seat and then begins to
develop its correction curves. The system takes 8 x 8,000 samples over 8 x 200-millisecond windows at each measurement
point for superior analysis and resolution of room acoustic detail.
As the system breaks the seats down into groups and compares them, further refining the process within each subgroup, an
optimally weighted response is determined for the whole area. Even the primary listening position is made to sound better.
This is the first audio application of clustering, using mathematical “fuzzy logic” to combine measured results to derive a
response curve that dramatically improves the sound quality in an entire room. Each of the 16 channels in the DP-2000
amplifier/processor has this software capability individually, residing in memory allocated by the D2Audio firmware.
Phase Technology, in addition to using a customized version of Audyssey MultEQ XT, is the first company to combine it with
a totally integrated system. The speaker, amplifier and calibration designers all knew the exact performance parameters
of all the other components of the system, resulting in a “closed loop system” yielding more predictable results in any type
of room.
Once the calibration and correction process is completed, the installer uploads the correction filters to the DP-2000
amplifier. If the room’s layout or furnishings change, it will be a simple matter recalibrate the room to its new layout, and
then reload the program changes – an elegant and future-proof solution.
WHAT SHOULD I REMEMBER FROM THIS?
Phase Technology, in partnership with D2Audio and Audyssey Laboratories, has introduced an applications-based digital
home entertainment system which offers the product variety and flexibility to fit easily into any room. Its performance
surpasses virtually all other systems at reproducing music and movies in a lifelike manner with precise localization of events,
seamless blending between all speakers and subwoofers, perfect tonal balance, and detailed alignment of frequency
response and phase/time relationships. Further, the system resolves these issues in any room and at every seat in the
listening area, opening up a new window into all audio and video program material. Listeners will hear sound just as its
artists, producers and directors intended it to be experienced. As the room’s acoustics are being set aside and system
limitations are removed by the unmatched technology of the Digital Audio Reference Theater System, dARTS literally
offers entertainment without boundaries!
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