Studio Finish

• Solid Oak front, top & bottom & Oak side panels with Black Finish.
• Neutrik “Speak-On input connectors.
• Mundorf Binding Posts
• Mundorf Crossover Components
• R. A. Smith Ltd.Copper Internal Wiring

Standard Finish:

• Solid hardwood front panels w/ choice of (3) species.
• Matching veneer species on sides
• Satin Finish.
• Mundorf Binding Posts
• Mundorf Crossover Components
• R. A. Smith Ltd. Copper Internal Wiring

Premier Finish:

• Hardwood Front Panel in Species of Choice (Depending upon availability and/or suitability – may incur surcharge at market price) w/ Mirror-Gloss Finish Option– or…
• Choice of Piano Lacquer (paint) Mirror-Gloss Finish on Front Panel.
• Choice of Veneer on Side Panels (many exotic species available) w/ Mirror-Gloss Finish Option or Piano Lacquer
• Mundorf Binding Posts
• Mundorf Crossover Components
• R. A. Smith Ltd.Copper Internal Wiring.

The Speed of an Electrostat with the Dynamics of a Jackhammer

SP Technologies Revelation Loudspeakers

TweekGeekSays: When I first heard this loudspeaker, I was reminded of the emotion and the thrill I experienced when I first heard high quality musical reproduction. It was a feeling I hadn't experienced in 20 years as an audiophile. This is the speaker I would own for my own system.

The Revelation is a truly unique and cutting edge system. From the 1" wave guide tweeter crossed over at 750 hz (that's right), to the hybrid bass design, to the precision crossover, and time/phase alignment. There are many proven principles, technologies and theories successfully implemented in this design. Nobody else has ever done this, with this degree of success, before.

Every "Millennial Reference Series™" boasts a crossover frequency to the woofer below 700 Hz. That is over two octaves lower than many other systems on the market! Such a low crossover frequency implemented utilizing a driver with a one inch diaphragm is almost unheard of.

Q: Why is the crossover point so low?

A: Because the acceleration potential or "rise time" of such a small diaphragm covering the entire upper half of the vocal region lowers transient distortion to the theoretical vanishing point. Diaphragm break-up modes, and the long wavelengths they are composed of, cannot propagate within the body of such a small diaphragm area. The result is the acoustic equivalent of a "perfect piston," transferring its energy of motion into the air with the entire vibrating surface moving back and forth in unison.

Now you can finally hear crucial midrange frequencies that are the embodiment of the human voice and other instrument tones -- without all of the distortion and "coloration" that woofer cones (including exotic carbon graphite, kevlar, etc. types) produce trying to operate well outside their "piston" region.

Q: How does that 1" driver go so low?

A: The Waveguide - Waveguides are similar to horns in that they change the air load that the driver "sees". The difference lies in the extremes.Our waveguides are characterized by the fact that they utilize relatively low compression ratios (a good thing). At higher frequencies the air load is virtually the same as a standard "baffle" mounted driver. This eliminates the associated distortion that is common at high frequencies with traditional horns.

Acoustic loading is only increased only at the lower frequency end of the driver's operating range. This provides added efficiency where it is needed most. At the low frequency range where its mechanical limits dominate and ultimately degrade its performance.

The effect of our waveguide on Dynamic Linearity (transient response) is nothing short of incredible. Reproduction of percussive instruments is truly life-like -- almost unnerving. Critical midrange frequencies of the human voice are reproduced with virtually no distortion, imparting a captivating immediacy seldom experienced in recorded music. The masking effects of Time Domain errors are minimized -- thus permitting the natural localization of instruments and performers in 3-dimensional space. Upon scientific analysis it will be found that our waveguide technology is truly an optimized design that leaves very little room for improvement.

The Waveguide also reduces diffraction effects
Another advantage of the waveguide is edge diffraction is virtually non existent. All frequencies that eminate "see" a more constant air load "impedance." This greatly improves the transient response of the speaker since there is no delayed energy reaching discontinuous enclosure surfaces and then "bouncing" back into the environment.

Seeing that edge diffraction is virtually eliminated, all of the tones that emanate from the waveguide appear to originate from the same point in space. This results in a coherent wavefront with respect to frequency. Such coherency preserves the time dependent information encoded in the recording.

Piston Power
All SP Technology Millennial Reference Series™ Loudspeakers employ aluminum cone woofers for true "piston-like" performance. Aluminum cones operate as near "perfect pistons" up to their "mass cut-off frequency" (an 8 inch aluminum driver is good up to around 1,000 Hz ). The aluminum drivers we incorporate just do not "break-up" and flex at the center as plastic, paper, etc. cones do.

The extended bandwidth provided by waveguide technology permits us to take advantage of the "perfect piston" behavior of a metal cone by crossing over at such a low frequency.

Hybrid Bass
SP Technology Precision Monitoring Products incorporate a proprietary, dual cavity, hybrid bass loading technique to provide unparalleled low frequency performance from a moderately sized enclosure. Back wave energy from the woofer is channeled through a short transmission-line type absorber that increases the loss of unwanted energy above box resonance.

A "hybrid bass" design was called for and has been successfully developed. The compact size and bass extension to 30Hz. (-3dB) of a ported design has been achieved with freedom from that "boxy" sound often associated with them. Low frequency transient response is fast and tight -- comparable with the best transmission-line designs. Boomy, bloated bass with that characteristic "overhang" is a thing of the past. Yet, bass "authority" and power must be heard to be believed.

Constrained Layer Enclosure Construction
Our Precision Monitoring products are constructed at all critical points with two layers of 3/4inch, Medium Density Fiberboard constraining an inner layer of "lossy" membrane. We also use large corner blocks at all panel joints (more info here).

Precision Crossover Alignment
All SP Technology products are designed with precision crossover alignments that include the "acoustic" response of the individual drivers in the final transfer function. Each and every design is painstakingly researched, repeatedly tested and modified to obtain the ideal summed driver responses. As much, if not more, time is invested in this single aspect of design as there is in any other area.

It is a costly and very time consuming fact that we go to extremes in order to guarantee that every aspect of performance under the control of the crossover is optimized. Impedance compensation at critical points is always implemented. Often this has secondary benefits in the area of power handling. Thermal time constants are modeled and conjugate solutions are implemented where appropriate and practical.

The components used in our products are all of a "high grade" in critical signal pathways. Polypropylene capacitors, air core inductors and precision resistors are used where there is a benefit to do so. All components are hand soldered and inspected. Final crossover adjustment to achieve a response of +/- 2dB (typically +/- 1dB) is performed on the production line for each and every enclosure. A "Proof of Performance" graph of the magnitude and phase response is included with each enclosure.

Uniform Frequency Response with a Controlled Radiation pattern
It is a common observation that many consumers and apparently designers, believe that a flat frequency response on-axis is all that matters, overlooking the effects of dramatic frequency response variations off-axis. We do suppose that this might not bother some listeners who seemingly don't mind sitting in the "sweet spot," with their head in a vise. We can scarcely imagine paying good money for a loudspeaker that demands such a committed audience.

But even if this wasn't an issue, then an even greater problem occurs when the drivers are not in-phase. Whatever the entire radiated spectrum of sound may be, you can be sure that the surfaces of the room will be reflecting it. That energy ultimately returns to the listener in the form of a reverberant field. If the reflected energy of the reverberant field does not have a similar spectrum or "signature" as that of the direct energy from on-axis, a very artificial soundstage will be the result.

With SP Tech Loudspeakers, sound is radiated into the environment with a constant 90° angle of dispersion from 500 to beyond 10,000 Hz, both vertically and horizontally. This means that as the frequency varies, the area that is "illuminated" by the driver remains the same over a 90° arch symmetrically and directly in front of the waveguide. Without some form of wave "directing" device this simply is not possible. Drivers mounted on a flat baffle produce a coverage pattern that often varies considerably. Many times they will be found to be very broad at the lower end of their operating range then begin to narrow as the frequency is increased, only to widen and then narrow again at the highest frequencies. This unpredictable behavior makes placement difficult and the optimal listening area quite narrow. The problem is highly multiplied when multi-way (3+) driver arrays are employed.

The advantage that controlled and constant dispersion offers is quickly realized when one is faced with "not so perfect" room placement options. In more ideal settings, the reduction of reflected sound from nearby walls permits the natural ambiance in a given recording to be heard clearly with less of the masking effect caused by early room reflections. A 90° dispersion angle is ideal for achieving this while still providing a very wide listening area.

Professional recording engineers will most certainly appreciate such constant dispersion characteristics. The ability to monitor recording sessions with nearfield accuracy and midfield freedom of movement is a combination seldom experienced and highly sought after.

In addition, with the recent advent of home theater, designers have sought to find ways to control the vertical dispersion of their designs in order to comply with the THX™ specification. A common technique is to employ two or more drivers operating over the same frequency range that are spaced some fixed distance apart. This method causes destructive interference at angles off-axis vertically from a pre-determined listening position. While this does effectively limit vertical dispersion to some degree, it most frequently does so in a rather erratic manner. Upon close analysis it can be found to produce a vertical pattern that varies with frequency. A stable, constant pattern at all frequencies is much more preferred and is a natural by product of waveguide technology. Hence, you will find that SP Technology Loudspeakers products are inherently more "home theater ready" than many products advertised as such and without their inherent musical limitations.

All Millennial Reference Series™ loudspeakers are made to order, and available in a variety of finishes. The finish chosen will have the greatest effect on the price. The standard studio finish is a matte finish textured black paint with a "leather-like" look. When you choose a veneer, the front baffle is finished in a high gloss black lacquer.