INTRODUCING a most significant breakthrough in home stereo reproduction...
The WHARFEDALE Model W80
VARIFLEX Speaker System This new concept completely eliminates the usual limitations involving speaker placement!
The VARIFLEX requires no special spacing apart, or from a wall or above a floor.
It can be used in pairs, anywhere in the room.
Or, two W80 speakers can be used to form a single 56" console.
VARIFLEX brings balanced stereo sound to the listener.
Stereo perception is preserved, rather than splattered promiscuously by uncontrolled room acoustics or speaker elements.
No need to disturb existing high fidelity systems. Does not require electronic equalizer.
Exclusive sand -filled construction, to eliminate undesirable enclosure resonances and coloration.
Modest in size (only 17" x 17 1/4" x 29"), the W80 is truly fine furniture, attractively styled to enhance rooms of virtually any decor.
Wharfedale ... a pioneer in reflected and indirect sound techniques, as evidenced by a number of such speaker designs introduced over the years ... refrained from introducing the W80 until the VARIFLEX technique could be refined into a carefully executed, easily utilized speaker system that not only would satisfy the acoustic objectives, but would retain the uncompromised quality of the reproduced sound. The W80 achieves both objectives successfully.
What is VARIFLEX?
Ordinary reflective and "omni" speaker systems have one thing in common: Sound dispersal is promiscuous and therefore subject to acoustical phase distortions caused by the shape and furnishings of the room.
Splattered sound, whether solely against a wall or through use of a conical reflector in the speaker enclosure, is uncontrolled sound. Hence, in the case of some types of systems, "optimum" spacing is recommended from a wall or above the floor. In other instances, sound is projected over a wide area, equally, from both speakers of a stereo pair.
But, in this case it should be obvious that the levels at which sounds of different frequencies arrive from both channels to a given point in the room are unequal and therefore unbalanced. In both instances, room conditions play further havoc because the distribution pattern of sound is fixed and therefore unable to accommodate the multitude of differences which exist between rooms and the general listening areas.
The Wharfedale VARIFLEX employs a variable device which bends sound waves in a definite and controllable manner so as to form the particular sound distribution pattern required by room conditions and /or the listening and decor needs of the user. It is capable of directing sound waves both in the vertical or horizontal planes, or any combination of these angles.
VARIFLEX. The Need for Controlled Sound.
There are differing schools of thought among acoustics engineers on how live sound reaches the listener in a concert hell. The loudspeaker engineer must also keep in mind the differences in operating conditions of a room in the typical home, as compared with the environment of the concert hall. There are, nonetheless, several significant considerations which must be taken into account, if any design of loudspeaker system may be said to have reproduced the original sound with reasonable fidelity.
Briefly, it must be recognized that the acoustics of a large concert hall, with its great expanse, high ceilings and generally hard surfaces are in sharp contrast to the shape, dimensions and furnishings of a typical room in a home. To emulate in the home the sound propagation characteristics of the concert hall too closely can, in fact, compound those characteristics into a disfiguration of the original sound. The program source, be it a disc, tape or broadcast, has already interpreted the conglomeration of actual sounds and reflections, as seen by the microphones which are the originating pick-up device.
Similarly, even in studio recordings, the careful separation and balancing of sounds achieved by the recording director and engineers must remain un-violated by the playback reproducing system.
Consider, too, that the propagative qualities of different musical instruments are quite dissimilar, so that where an entire orchestra is concerned, the direct vs. indirect distribution of sound is not only a function of the concert hall's acoustics but also, and very prominently, a function of the individual instruments and their respective positions on stage. In studio recording, where close pick-up techniques and soundproofed rooms are frequently employed, the distribution pattern of the various musical instruments again takes on a tonal quality that can be quite different from that of an open concert hall.
Clearly then, whether the source of the live program is the concert hall stage or the recording studio, the sole purpose of the loudspeaker system is to bring to the listener the sound as originally experienced.
Therefore, a speaker system which uses a predetermined ratio of direct to indirect sound distribution, and applies reflected sound that cannot be adjusted, is obviously adding an aural effect that is not in the original program ... and that effect will vary uncontrollably with room acoustics and furnishings. Similarly, a speaker system which attempts to simulate the effect of wide -angle propagation of sound (usually through use of an inverted reflecting cone or by an array of speakers in a circle or several quadrants of a cabinet) merely creates a splashing or scattering effect that is also fixed, and equally affected by room acoustics. The basic thought that needs to be borne in mind is that the listener to any live performance is almost never surrounded by the program source, unless perhaps he is one of the musicians! The totality of the sound comes from a particular direction, and depending upon the nature of the sound (voice vs. small combo vs. full symphony orchestra, etc.) it is either a confined point in space or over a broad dimension. True "stereo ", therefore, is the listener's ability to distinguish the direction of the total sound and the individual components of the sound. If this requirement of "stereo" is compromised, then all that really results is a room full of sounds unbalanced and unrelated to the acoustical and musical composition of the original. If one wishes merely for that, it can easily be accomplished using mono programs on speaker systems of the fixed reflector and "omni" inverted cone types. This is, in fact, exactly what was often done in the earlier days before stereo, to enhance the spatial effect of mono programs.
VARIFLEX---What It Does
Low frequency sound waves (bass and low mids) spread energy throughout a room with a minimum of attenuation and do not exhibit noticeable restriction of dispersion. It is often stated, therefore, that retention of the stereo characteristics for such frequencies is not really important. It would be better to qualify that viewpoint by saying that the perception of directionality of the bass and low mid frequencies are not "as critical" as for the rest of the spectrum. However, the retention of a sense of direction does preserve the fidelity and the "balance" which existed in the original program. Speaker systems which house the bass speaker in a manner which produces a 360° dispersion, for example facing downward to radiate against the floor, appreciably dilute whatever directionality might have been retained. In the model W80 VARIFLEX, the bass speaker faces upward and into a mixing chamber ... a carefully oriented arrangement of complementary mid and treble speakers, to blend the sounds of the entire ensemble ... just as these same sounds blend within the orchestra.
We agree with the usual contention that the normal mid and treble ranges provide the greatest recognition of "stereo" spatial separation. It is, in fact, for this very strong reason that the dispersion characteristics of those frequencies must be controlled, rather than left to the mercy of individual room acoustics and other varying operating conditions. (The importance of this was previously explained.) For these reasons, the VARIFLEX incorporates a device which permits the user to literally direct the mid and treble frequencies in any direction needed to accommodate room acoustics, furnishings, placement and spacing of the speaker systems. So completely independent of these factors is the VARIFLEX, it makes no difference how far apart the speakers are from each other, or how far away from a wall. If desired, the speakers may even be mounted off the floor on a wall, and still provide the same degree of performance and operating flexibility.
This exceptional versatility is achieved by means of a 10" hard -surfaced disc, with universal mounting, which enables it to be placed in any combination of vertical –to-horizontal angular positions. It is, in effect, a variplanular reflector. The disc is situated with respect to the speakers, so that both reflection and deflection can be achieved, sending the sound waves into the room in any desired direction. It is round in shape to prevent unwanted sharp diffractory effects (as would occur from a rectangular device) as well as to provide only the amount of reflection the design intends. With the cabinet placed against a wall, the surface of the wall is, additionally, brought into play for even broader spread of the sound. The dispersion characteristics of the individual mid and treble speakers are carefully tailored to employ only that portion of the variplanular disc required, so that an amount of sound is permitted to "escape" from the "mixing" chamber to complete the sound distribution pattern in directions other than that being directed by the disc.
What, in total occurs, is that sound is projected by the disc into that part of a room where it is needed but would otherwise be lacking in level and /or frequency response, while the remaining normal distribution of sound from the speakers covers the rest of the room.
The W80 Components
A Four-Way System
Only the finest, professional grade components are used. The woofer is a heavy duty 121/2" unit with massive 9 1/2 lbs. magnet assembly.
The long -throw cone uses a very low resonance, high compliance rubber suspension for rich, deep bass. The bass chamber incorporates Wharfedale's exclusive sand -filled construction for elimination of cabinet coloration. The midrange employs a 5" curvilinear cone in a separate chamber acoustically isolated from the bass housing. Two different treble speakers are utilized, one for the sub -treble range; the other for extreme highs. Both have low mass aluminum voice coils and pressure dome diaphragms, Phase compensating diffusers provide for smoothest, linear response over the entire operating range ... right out to inaudibility.
All the speakers are arranged in a carefully calculated configuration, to eliminate a common fault with multiple speaker systems: Acoustic division of sound. With the W80 you don't listen to part of a musical instrument but to all of it, and from its intended place in space.
Prices: W80 $289.95 ea. B68 25.75
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Speakers Spaced Normally Apart
With two W80 speaker systems spaced 6 to 8 feet part, the vari-planular discs can be set as shown. The disc is tilted back towards the wall, by an amount determined by the distance from the wall that is most convenient to the user. Instructions provided with the system describe how to set the disc. In this application, the exceptionally wide angle dispersion of the system is used in a normal fashion, while at the same me deflecting some of the sound to the wall, for still greater reflection and dramatic "openness" of sound.
Speakers Spaced Far Apart
With two W80 speaker systems spaced far apart even s much as 15 feet or more the vari-planular discs are et as shown. The discs in this case have been tilted back for deflection to the wall, and at an appropriate angle toward the center for reflection of the sound to what otherwise would remain a void between the two peakers. This fills the "hole" in the middle and results n a very smooth sound pattern along the entire distance. Heretofore, it has been necessary to introduce "third channel ", with a third speaker located between he usual two, to overcome this problem.
Speakers Spaced Very Closely
With two W80 speaker systems spaced very closely together under six feet apart the vari-planular discs are set as shown. In this case, the discs are tilted back or deflection to the wall, and at angles away from the center for reflection of sound to areas that otherwise would not be reached by sound in proper balance.
Listening Areas Off Center From Speakers
Since sound from a VARIFLEX speaker can be projected n any direction, it becomes obvious that a pair of W80 can be set up to cope with a situation where the general listening area is sufficiently off axis from the location of the speakers to cause a serious compromise of he stereo illusion. In such instances, the vari-planular discs are set unequally, with each W80 being set to cover respective areas as needed.
Expanding the W80
The W80 can be used in multiples, for still greater power handling capacity and superior acoustical coverage of particularly large areas, as in a small auditorium, music appreciation assembly hall, catering establishments, etc. Two WBOs are placed side by side, connected to one stereo channel. Another pair is connected to the other stereo channel. The variplanular discs of a pair of W80 would be tilted back for wall deflection, and away from the center to provide an extremely wide angle of projection, or adjusted for an unequal sound pattern, where room conditions dictate the need.
Single Console Stereo
The ultimate in applying Wharfedale's W80 VARIFLEX speakers. Two W80s can be employed as a "single" console to provide uncompromised, perfectly balanced broad angle stereo ... using only 56" of wall space. The two speakers are placed on their sides on an optional set of legs (model B68), with the "bottoms" of the cabinet facing each other at the center. The resulting paths of sound are outward toward the ends, and over the top and around the underside. The variplanular discs are tilted back for wall deflection, and each disc is also turned at angles away from the center to reflect sound out from the ends of the "console" ... resulting in an acoustic lengthening of the console by several feet! Overall distribution of sound is remarkably smooth, and there is the added advantage of close coupling of the extreme low frequencies, yielding a bass response of exceptional depth and clarity.
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Wharfedale British Industries Co., Westbury, N. Y. 11590, USA. Div. Avnet, Inc.
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(Audio magazine, 11/1969)
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