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EX Speaker Series

Development of the Pioneer EX Speaker Series

Pioneer EX Speaker Series

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Introduction

Pioneer’s heritage as a loudspeaker manufacturer began over 60 years ago. And for the past 30 years, the company has emerged as a world-class leader in professional studio monitoring loudspeakers, under the TAD brand name. TAD speakers and drivers have built a pre-eminent reputation as the best speakers for mastering and monitoring. In 2001, Pioneer started a research and development program to take the experience and technology of the professional speakers and design a speaker of the highest caliber specifically for home use. The requirements for professional monitor speakers are in reality very similar to those for the home – accuracy (both tonally and spatially), resolution and dynamic control. Pioneer applied many unique solutions to maximizing its capability in these areas. Additionally, whereas most studio speakers are used in carefully tailored acoustically controlled environments, loudspeakers for the home are typically used in a wide variety of environments. Extensive effort was put into understanding the interaction between the loudspeaker and the room and finding innovative solutions to the problems encountered.

Over three years of research and development went into the design of the TAD loudspeaker with the goal of bringing the studio experience into the home. The result was the TAD Model 1. Winning numerous awards and receiving outstanding praise from critical review, the Model-1 has become a reference for both the home audio market and the professional market.

Pioneer now introduces its latest speaker, the EX series, based on the technologies developed for the Model 1 but in a more affordable package. In the following pages we will discuss the technology and features that have already made the EX speaker an award-winning product.


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Space and Directivity

Amongst all the components in a sound system the loudspeaker is the one item whose performance is critically dependent upon the location within, and the characteristics of, the listening environment. A lack of understanding of the speaker and room parameters that govern this relationship will lead to, at best, a sub-optimal performance or many hours of trial and error to optimize the performance within the listening space. Much work has been published dealing with loudspeakers in rooms, mostly concentrating on the influence of standing waves (due to the room boundaries) upon the positional requirements for the loudspeaker and the listener. Poor positioning of either can lead to uneven, exaggerated bass performance and differing sound quality for listeners seated in different locations within the room. When listening to stereo it is quite common to have a “sweet spot” where the sound is optimum, and this spot can often be very small, perhaps confined to just one listener! This is far removed from present day requirements of multi-room, (“sound everywhere”) multi-channel home theater for the whole family. Nowadays the sound must be optimized for all locations.

In a studio environment the acoustics are carefully controlled to minimize the effects of standing waves and room boundaries. Bass “traps” are installed to reduce bass boom and allow greater freedom of positioning. In the home environment it is not always possible to fully treat the room, but careful positioning of the loudspeaker and listener (aided by readily available computer simulation programs) will allow for greatly improved bass performance. However, to fully accomplish the goal of optimizing the sound in the room, there is more to consider than just the standing wave problem. The radiation characteristics of practical loudspeakers determine their perceived tonal balance in different rooms. Unlike an electronic device such as a DVD player or amplifier, a loudspeaker has an output response to its input that is 3-dimensional. It radiates sound in all directions and the nature of the sound is not identical in all of these directions.

For example, the sound radiating to the side of the loudspeaker is not the same as to the front and this has implications for how stereo images are formed, how the loudspeaker sounds when placed near walls and how the sound is influenced by different rooms. Some simple physics will illustrate why this happens and how this leads to a design approach that ameliorates the problems.

Let’s consider a simple cone drive unit in a box, reproducing sound at various frequencies. At low frequencies where the wavelength is large compared to the cone dimensions, the radiated sound will spread uniformly around the loudspeaker. The sound level is the same in all directions. As the frequency is increased and the wavelength gets smaller the sound starts to concentrate in the forward direction, but at the expense of the amount spreading to the side and rear. The sound essentially becomes focused, just like the beam of a flashlight compared to the light emitted from a bare bulb. The bare bulb lights the room much more evenly than the flashlight. This effect is related to the size of the loudspeaker cone. The bigger the cone, the lower in frequency at which the beaming will become significant and vice versa.


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Clearly then, if such a simple loudspeaker is designed to have a relatively flat response on axis (the forward direction) it will sound dull when listening off-axis due to the loss of the higher frequencies. This is illustrated in Fig 1.

Now most quality loudspeakers are not as simple as this example. They comprise typically of at least a woofer and a tweeter. This arises from the wide frequency range that the speakers must reproduce and the differing requirements for adequately doing so. To reproduce loud bass sounds a lot of air must be moved, albeit quite slowly. As a result the woofer has to be large and therefore heavy. To reproduce high frequencies such a large quantity of air does not need to be moved, but it does need to move fast and so the tweeter is small and light. It is the different physical size that concerns us here. As we have shown in Fig 1, size does matter when considering the focusing of the sound. The woofer will start to focus at a much lower frequency than the tweeter.

When two drivers are combined together with its dividing network, our aim is to get as flat a response as possible over the whole frequency range. But in which direction? Traditionally we have chosen the design axis to be directly in front of the loudspeaker. The foregoing shows that such a choice means that in other directions the response cannot be flat. We have a sound that starts to lose energy as frequency increases, up to the point where we cross over to the tweeter. Here the sound level jumps back up (since the tweeter is still relatively non-directional at this frequency) before starting to lose energy at some higher frequency. This is shown in Fig 2.

Fig 1. Driver directivity Black – On-axis responseRed – Large driver off-axis responseBlue – Small driver off-axis response


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This dip in the off axis output falls right in the most critical region of our hearing sensitivity.

Another consequence of splitting the frequency range between two or more drivers is brought about from the physical separation. In the frequency range where the sound transitions from the woofer to the tweeter, both drivers are active. In this range, while the on-axis sound from each driver can be caused to add together beneficially, when the listener moves off-axis (normally in the vertical direction) to a location where they are no longer equidistant to each driver interference occurs This results in peaks and dips in the combined frequency response as illustrated in Fig 3.

This is in the vertical direction for most loudspeaker configurations, although in a typical center channel loudspeaker it is in the horizontal direction.

Fig 2. Speaker system directivity Black – On-axis responseRed – Off-axis response

Fig 3. Vertical directivity Black – On-axis responseRed – Above design axisBlue – Below design axis


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The consequence of the nature of sound radiation from a driver, and the necessity of splitting the frequency spectrum across two or more drivers, results in a response that is not uniform in all directions. This has serious consequences for how the loudspeaker interacts with the room, and how stable and precise its imaging capabilities are in stereo and multi-channel.

In stereo listening we perceive sounds that come not only from each of the two loudspeakers, but phantom images that hang in space between the loudspeakers. The apparent position of these images depends upon the relative level and phase of the signals feeding the two loudspeakers.

As an example, consider a musical instrument (a violin perhaps) that is balanced to be in position at the center of the sound stage. The sound from this violin comprises of the fundamental and its harmonics occupying a wide frequency span. If the two loudspeakers do not have identical frequency responses, then the relative level between the two speakers will differ between the fundamental and harmonics. Resulting in each harmonic appearing to come from a different position between the loudspeakers. The image of the violin is now fat and bloated. Additionally, as different notes are played, the sounds from the violin may appear to wander across the soundstage. The image accuracy, stability and quality therefore depend on the two loudspeakers having identical frequency responses.

How does the directional characteristic of the loudspeaker influence this situation?

Looking at Fig 4 we can see that for a centrally seated listener, the angle subtended to each loudspeaker is identical. Assuming the speakers are placed symmetrically, then the response from each loudspeaker is identical, though not of course necessarily the same as the on-axis response. However, for an off-center position, such as #2 or #3, the listener is now at a different angle to each of the two loudspeakers (on-axis to one and off-axis to the other). They now have different frequency responses and so the image quality is degraded. Additionally the tonal quality of the sound will be different from the two speakers, so a sound that pans from left to right will change its character as it traverses.

LEFT RIGHT

#1 #2#3

Fig. 5 Listeners seated away from the central positionhear different responses from the left and rightloudspeaker due to degraded off axis performance

Fig 4. Loudspeaker/ Listener positioning


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We haven’t even considered influence of the room yet.

In a typical home listening room we have a whole extra set of problems to deal with. Do you ever listen to the sound of your own voice or that other people as you enter a room and note how different it sounds? A church with it’s highly reverberant characteristic provides an extreme example of how the room can alter sounds. Here the voice becomes rather indistinct, overwhelmed by the reverberation, and it is difficult to locate just where the sound is coming from. It also sounds considerably louder than it did outside. The reason for this is that a considerable amount of the sound that had been directed away from you outdoors is now returned, though much of it highly delayed and perhaps modified due to absorption from any furnishings present. A home is rarely this reverberant, but falls somewhere between the extremes. When we now listen to a loudspeaker in the room, we hear both the direct sound (the on-axis sound that comes straight to us) and the indirect sound from all the reflections (the sum of the entire off-axis sounds). Although our hearing process has some discriminatory capability to differentiate between direct first arrival sound and the later reflections (and even the direction of these reflections), together they all contribute to our perception of the sound balance of that loudspeaker in that room. Yet those off axis sounds, as we have seen, do not have flat response. As we move from room to room and change the ratio between direct and indirect sound, we will therefore perceive a difference in the apparent tonal balance of the loudspeaker. Even changing the distance between the loudspeaker and listener will alter the sound balance. The further away we are the more the reverberant sound dominates and vice versa. This makes life very difficult for the loudspeaker designer. What we really need is to re-engineer the loudspeaker to minimize the non-uniform directivity and then all of our problems are solved (almost). But how…?

Perhaps a short summary at this point will clarify our goals. Conventional loudspeakers comprise of a number of spaced drivers each with differing directivities, giving rise to non uniform off axis responses, mutual interference effects, subsequent imaging, sound balance and room interaction problems. We simply have to match the directivities and move the drivers as close together as possible.

Of course the closest we can get is where the two drivers share the same physical position. We call this coincident. The tweeter is positioned within the bass driver, ideally mounted at the apex of the cone and co-axial with it. No separation means no interference. Because both drivers share a common acoustic source position, all sounds within the operating range of the CST (Coincident Source Technology) arrive at the listener at identical time, preserving the timing integrity of the original sound. Furthermore the cone itself acts as a waveguide, imposing upon the tweeter identical directivity characteristics to that of the bass driver. This is the basis for the CST driver.


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The CST Driver

We can see an image of the driver in Fig 5 and its construction in Fig 6.

The driver consists of a custom high-pressure die cast aluminum chassis with neodymium magnet, designed to minimize interference to the back wave of the midrange cone. The tweeter diaphragm is mounted at the apex of the midrange cone and shares with it a common magnet system with dual gaps, one for the tweeter and one for the midrange, driven by a powerful 55mm diameter 9mm thick neodymium magnet. Copper caps over the pole piece function to reduce eddy current distortion from the voice coils, extend bandwidth and minimize inductive interaction between the two coils. The voice coils are edge wound copper for lightweight and high sensitivity, 52mm in diameter for the midrange and 25mm for the tweeter.

Fig 5. Coincident Source Technology Driver

Fig 6. Coincident Source Technology Driver construction


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To ensure the smoothest propagation of the sound radiated by the tweeter, all discontinuities in surface profile surrounding it must be minimized. Any such discontinuities produce secondary sound emissions, blurring the sound and causing response irregularities. To correct this, a short horn is interposed between the tweeter and midrange diaphragms to blend the profiles and the midrange surround is made as shallow as possible commensurate with the movement requirements of the midrange cone. In combination these features result in outstanding off-axis performance in all directions when considered against conventional spaced driver arrays. This can be seen in the excellent measured off-axis performance of the CST driver. Fig 7.

Beryllium and the CST driver

The tweeter diaphragm is made from Beryllium just 60 microns thick, the same diaphragm used in the TAD Model 1.

TAD has over 30 years experience in making Beryllium diaphragms, using a proprietary vapor deposition manufacturing process. We start with a pellet of Beryllium, and vaporize it at high temperature in a vacuum, spraying it at a copper target formed in the shape of the diaphragm until the required thickness coating is achieved. Subsequently the copper is etched away to leave only the Beryllium. The process takes several hours for each diaphragm, but results in unique properties. The surface and internal structure can be seen in Fig 8.

Fig 7. Off-axis responses


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Why Beryllium?

The diaphragm of a loudspeaker driver should ideally be light and stiff. Lightness directly contributes to improved efficiency. Less power is wasted in moving the cone/dome back and forth. This power is normally dissipated in the voice coil causing it to heat up, often dramatically, and in so doing alters the characteristics of the driver. This is a dynamic effect, depending upon the past history of the music and results in compression of the sound and squashed dynamics. Most materials that are light enough suffer from inadequate stiffness. At low frequencies the whole dome moves as one surface, correctly conveying the motion of the voice coil to the surrounding air to produce sound. At the higher frequencies, the cone/dome no longer moves uniformly, breaking up and bending and flexing across its surface resulting in resonances and a lack of faithfulness in reproduction. Most materials that are used in drivers exhibit this undesirable behavior within their operating band, and great skill is required in their design to control and minimize the negative effects. A few materials manage to push this effect to the edge of their operating band but very few manage to move it significantly beyond. Beryllium is the stiffest and lightest material available. The material property table is shown in Fig 9.

Fig 8. Surface and cross section photo micro-graphs of Beryllium cone


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This shows the superiority of Beryllium. The property that governs the break up frequency is the velocity of sound in the material. The higher the better. In comparison to other materials, such as aluminum and titanium, Beryllium has more than twice the sound velocity. The only material that outperforms it in velocity is crystallized diamond, but this is nearly twice as heavy, compromising efficiency. As a result, the first break up mode in the CST tweeter is close to 60kHz, nearly an octave higher than traditional domes and it maintains useable output to 100kHz, providing unparalleled bandwidth from a point source radiator. This allows the CST tweeter dome to maintain perfect pistonic motion throughout its operating bandwidth. Although Beryllium is also used for the midrange cone of the flagship TAD Model 1, it’s manufacturing cost rules it out for the midrange cone of the EX speakers. Instead, we looked at the characteristics of the other available materials for one that most closely met our needs.

The next best material on the above list is magnesium. Its density is as low as Beryllium and is much lighter than Aluminum. By careful design of cone shape and size, we have engineered a midrange cone whose first resonant mode is at 6.5kHz, more than an octave above the range over which we use the driver.

Fig 9. Material property table

Material

Density

g/cc Young modulus (*E10Nm-2)

Velocity m/s

Inner loss

Aluminum

2.7

7

5092

0.003

Titanium

4.4

11.9

5201

0.003

Beryllium

1.85

28

12302

0.005

Boron Alloy 4.5

23

7149

0.005

Paper 0.2-0.8 0.03-0.6 1200-3750 0.02-0.1 Magnesium

1.8

4.5

5800

0.005

Ceramic Graphite

1.8

18

10000

0.01

Crystallized Diamond

3.4

90

16270

0.014


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Bass Driver

The bass drivers have benefited from extensive development work, and have been designed specifically for the EX speakers. As with the CST, the bass driver consists of a custom high-pressure die cast aluminum chassis with neodymium magnet, designed to minimize interference to the back wave of the bass cone.The driver is shown in Fig 10 and its construction in Fig 11.

Fig 10. Bass Driver

Fig 11. Bass Driver construction


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The primary components of a bass driver that contribute to the sound quality are the cone material and the motor structure. To produce loud deep bass the bass drivers need to move a long way to displace lots of air. They must do this while resisting the high back pressure from the air trapped within the bass enclosure. Low mass is not so important therefore the cone can be optimized for strength.

Cone construction

The cone for the EX bass drivers achieves immense strength from its sandwich construction. Woven aramid fiber cloth is bonded together with non-woven carbon fiber matting and polypropylene sheet using special resins for a total of 10 layers. The weave geometry –is carefully chosen to maximize strength and minimize cone distortion.

In conventional bass drivers, the center of the cone is removed to allow for attachment of the coil, and then the dustcap is bonded to the cone. This process weakens the cone. For the EX driver, the dustcap and cone are formed from one piece and then bonded directly to the voice coil former, resulting in enhanced stiffness and control of the voice coil for improved dynamic performance.

Coil and Motor

The coil itself is 65mm diameter. The large diameter gives the driver very high power handling. This is important for the dynamic performance of the driver. As more and more power is fed to a driver the voice coil heats up. As it does so the coil resistance increases and alters both the way the driver loads its crossover network and the sensitivity of the driver. These changes can be significant for the sizes of voice coils typically found on bass drivers. Because the heating takes time, the result is a dynamic modulation of the driver performance based upon the past history of the music that the driver is reproducing. This robs the music of its dynamic contrasts. The coil on the EX bass driver is more than double the size of typical voice coils and guarantees outstanding bass performance from the EX speakers.

The motor structure is designed around a 60mm diameter 7mm thick Neodymium magnet and is inherently magnetically shielded. This type of design makes maximum use of the flux available from the magnet. Combined with the superior strength of Neodymium compared to conventional ferrite magnets this allows for a powerful motor in a compact size, minimizing the obstruction of the rear wave from the cone.

The magnet structure of the bass driver also provides venting through the center of the pole piece with a large diameter hole. This reduces pressure build up under the dustcap, further contributing to the low distortion and helping cool the voice coil. The vent is smoothly contoured so that the air always flows freely without turbulence.


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Suspension

At the extreme excursions required at low frequencies, the linearity of the driver is controlled not just by the motor design but also by the design of the rear suspension and the cone surround. The EX bass driver utilizes an optimized geometry rear suspension combined with a multi-roll surround at the cone perimeter.

Most conventional drivers use a half roll surround, typically made of rubber or foam. However, at large excursions, the half roll does not behave identically on the outward movement compared to inward, resulting in distortion. The multi-roll surround overcomes this limitation. Both of these components have been optimized using finite element analysis (FEA) to allow high excursion with low distortion.


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The Loudspeaker Cabinet

The loudspeaker cabinet fulfills many roles. It must support the drivers, contain the back-wave from the bass driver, define the visual style of the system and be as inert as possible so as not to detrimentally affect the sound quality of the speaker system.

This is not an easy task. Particularly for large speakers, the cabinet can be a significant source of unwanted vibration and sound. Consider an analogy with a guitar. An acoustic guitar takes the mechanical vibration of the strings and through the coupling provided by the bridge transfers these vibrations to the body of the guitar. The body is constructed in such a way that through multiple resonances these vibrations are amplified and radiated as sound we can hear. The art in guitar design is to choose shapes and materials that give the tonal character that the designer wishes. Without the amplifying action of the body, the strings would produce very little sound, as for example with a solid body electric guitar, where we rely on electrical amplification to hear the sound.

Now think about the loudspeaker. The cabinet can be likened to the body of the acoustic guitar. It receives energy from the back and forth motion of the speaker cone, both as mechanically conducted through the driver chassis, and acoustically coupled through the air in the cabinet. This energy causes the cabinet to vibrate and “sing along” with the drivers. However, in this case we do not want this to happen. The loudspeaker is a musical re-producer, not a producer, of sound. It must not impart its own character upon the music being played.

The cabinet must be constructed in such a way as to minimize its vibration. Standard practice for cabinets is to use flat-sided box construction, typically from MDF. This is not adequate for a high quality speaker, though it is very cost effective for manufacturing! Flat panels have poor strength. An improvement is obtained by using cross-bracing. Braces tie opposite faces of the cabinet together to prevent them from vibrating in and out. Unfortunately, due to manufacturing considerations these braces have to be made slightly smaller than the internal dimensions between the panels, and therefore they rely on the glue bond to control the flexing.

The EX speaker employs an alternative and superior technique. The side panels of the enclosure are constructed from 10 layers of 1/8” thick MDF and are curved before laminating. Curved panels are inherently stronger and more rigid than the equivalent thickness flat panel. Combined with laminated front and rear panels up to 3” thick and internal circumferential bracing, the result is a very strong inert enclosure.


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The construction can be seen in Fig 12.

Fig 12. Cabinet construction design


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Internal Standing Waves

In a listening room, at low frequencies the speaker excites standing waves that alter and color the sound of the bass. This is a well-known problem, and one that is difficult to control. The bass sound quality is dominated by the room response, but by careful positioning of both the speaker and the listener the worst of these can be ameliorated.

In a similar way, the driver can excite standing waves within the speaker enclosure. These are especially troublesome in tall, floor standing speakers as their frequency falls within the pass-band of the bass driver. The standard method of controlling these standing waves is to add absorbing material inside the enclosure. However. at the frequencies that these waves typically appear, the absorption efficiency of the material is not very high and so a rather large amount of the material has to be introduced in order to have an appreciable effect. Such a large amount has a significant drawback, particularly in bass-reflex speakers (such as the S1-EX), in that it greatly attenuates the effectiveness of the reflex loading. The result is a loss of bass output, and if the material is not well supported and hence is able to move, the bass character of the sound changes with sound level and adversely affects the accuracy of the bass dynamics. This is illustrated in Fig 13, where a response plot (upper curve) is shown of a typical floor standing speaker, with all damping material removed to clearly illustrate the influence of the standing waves. In this example, the first problem occurs at 200Hz, with additional ones at 400 and 900Hz.

Fig 13. Acoustic Balance Drive (ABD)


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Just as in a room, where by careful re-location of the speaker and listener within the room can be an effective method of controlling the dominant standing waves, a similar approach can be used to solve the problems within the speaker enclosure.

The solution employed in the S1-EX, Acoustic Balanced Drive (ABD), arrived at by extensive computer modeling of the acoustic interaction between the driver and the enclosure, is to use a pair of bass drives symmetrically positioned around the vertical center-line of the cabinet. This results in a complete cancellation of the 200Hz standing wave along with significant reduction in the higher frequency standing waves. This is achieved without the addition of any absorptive material, and as a result there is no loss of bass output (as can also be seen in the response plot above) or modification of bass dynamics.


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Time Alignment

It is often said “timing is everything”. Well this is also important in music reproduction.

We require that all the components in a music signal arrive at the listener simultaneously in order to faithfully reproduce the original event. When we reproduce the signal through a loudspeaker it is quite common that components of the signal at different frequencies arrive at the listener at different times. This is especially so for multi-way speakers, where the signal is divided into different frequency bands for the bass, midrange and tweeter.

Because of the physical displacement of the drive units their acoustic centers are displaced so that they are not equidistant from the listener. These arrival time differences also change as the listener moves around in front of the loudspeaker. The solution for the midrange and tweeter has already been discussed in a previous section, the CST. Once the drivers are aligned concentrically and coincident, all sounds arrive simultaneously for all listener locations. For the bass driver and vent, once the position of their acoustic centers is defined they can align it on the cabinet so that the arrival time matches that of the CST for the defined listener position.

So far, the time alignment has been concerned with the relationship between the drivers in each speaker and the listener. A further concern over timing arises with multi-channel systems, such as a five-channel surround sound system. In order to create the most accurate, enveloping sound field, all the drivers in all of the speakers should be aligned to be equidistant from the listener.

Fig 14. Drive Unit Time Alignment


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Imagine a sphere centered on the listener. See Fig 15. Every point on the surface of the sphere is equidistant from the listener. Now, if the speakers are designed so that the baffle surface upon which the drivers are mounted is shaped with a radius matching the imaginary sphere, and each of the speakers is appropriately positioned, then every driver will be perfectly aligned. This is the approach used for the EX series.

Fig 15. Imaginary sound sphere


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Crossover Network

The art and science of crossover network design is to blend all of the drivers together seamlessly, so that the music is sensed to be coming from a homogenous source and not a collection of disparate parts. The function of the crossover network is threefold:

1. Frequency Division

�. Frequency Shaping (Equalization)

�. Impedance Control

Frequency Division is the fundamental function of the crossover network, and the choices of where to cross between the drivers is governed by the driver responses and resonances, the required power handling, directivity and distortion.

Frequency Shaping corrects the inherent response of the drivers to give the system the most accurate voicing possible.

Impedance Control allows the system to present a sensible load to the amplifier without wasting power into low impedances.

In the EX series of speakers, each of these factors has received careful attention and many hours of critical listening to optimize the performance of the system. The network is three-way with 3rd order electrical slopes on all sections. When combined with the driver responses, the relative phase responses between the sections give the best blending of the drivers for both the on-axis response and the power response of the system. This ensures that the in-room response of the system is consistent with the axial response and so the speaker will sound its best in a wide range of listening environments. The crossover frequency between the bass drivers and the CST is set to 350Hz. This is high enough to minimize the excursion of the CST driver while still low enough to get seamless blending with the bass driver pair.

All inductors used in this section are of high quality laminated steel core construction or air core. Many speaker systems pay too little attention to the load presented to the amplifier by the speaker. Poor crossover network design can lead to excessive current being drawn from the amplifier, making unnecessary demands and robbing the music of its bass dynamics. This has lead to amplifiers designed with the capability to source very high currents to feed such hungry speakers, but this is not an optimum solution. The bass driver low-pass filter in the EX speaker uses a conjugation network across the driver to ensure that the impedance of the network as seen by the amplifier is not too low.

This contributes to the outstanding bass dynamic capability of the speaker.


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The crossover frequency from midrange to tweeter is set at 2.2kHz. At this frequency we are still 3 times lower than the first cone breakup frequency, and the 3rd order network ensures that this mode is well suppressed.

The superior tweeter efficiency that results from its location within the midrange driver allows us to attenuate the input by 16 times at the crossover point, ensuring minimal power compression from the tweeter and high reliability.

All inductors in the midrange and tweeter crossover are air cored, and the capacitors are high quality film caps.

Conclusion

Pioneer has been breaking the boundaries in speaker innovation for decades. Through the years, many advanced technologies have been researched and then applied to products that have been critically acclaimed in the industry. It all began with the design and production of dynamic speakers. The experience and expertise built up through the years with TAD culminates in the creation of our masterpiece, the EX Speaker Series. The technology discussed in the previous pages is what contributes to the superb, natural sound from these premium speakers. Every step in the design process has been meticulously undertaken to ensure that the prestigious EX Series really does deserve its status.

Pioneer Electronics (USA) Inc. Post Office Box 1540Long Beach, California 90810.1 (800) PIONEERwww.pioneerelectronics.com

Disclaimer:Specifications and design are subject to modification without notice.This document may contain typographical errors and the colors of the depicted products may deviate slightly from reality. Consult your authorized Pioneer dealer or www.pioneerelectronics.com to confirm product features and specifications.

Copyright © 2005-2006 Pioneer Corporation. PIONEER, SOUND. VISION. SOUL, and TAD are trademarks of Pioneer Corporation.

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