Enclosure
 

NSR does not pursue system designs by merely following theoretical acoustic trends. Neville Thiele and Richard Small, while gifted mathematicians, were not speaker designers! Though their theory’s revolutionized loudspeaker design, resonant box theory is still just that, theory. Trade-offs and losses are an inextricable byproduct of any system designed using these mathematical models alone.

An amplifier is designed to control a driver’s potential for wayward movement through its damping factor. Although the amp may be successful at this, it cannot control the resonant air and turbulence within the box. The box may function optimally at a specific frequency, but throughout the spectrum range, may fail miserably.

While sealed boxes present a smooth load to the amplifier, bass response rolls off at half the rate of a ported enclosure. Ported systems have several factors that can adversely affect the low frequency response and sound quality. A port is only effective at the resonant frequency for which it is tuned and increased amplitude will only cause interference. The port cannot change its physical attributes in order to accommodate more airflow! The net result is flat, boomy bass, and low frequency wave distortion. Ported enclosures are designed to work as a resonant system and this physical design actually works against itself. A ported system takes time to excite. Then, post excitation, the bass waves lag and suffer some degree of delay before they stop. A ported system is literally a loose cannon!

Through years of painstaking research, NSR has developed its own enclosure parameters, essentially employing a tandem pull/pull motor system in a non-resonant/anechoic sealed box!. Sonically, these strictures, combined with our patented Acoustic Projection Lens technology, are the genesis of a new, more fortified, and considerably more stable bass system. NSR systems can reproduce low frequency waves well below the threshold of human hearing, on into the subsonic spectrum, without breakup! NSR developed the acoustic material used to line our enclosure that allows it to function as an anechoic chamber, virtually eliminating box resonance. The yield is a crisp, distinct, and powerful bass wave spectrum not found in any other system known today!

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Acoustic Projection Lens (or APL)
 

The uppermost APL from the D1

While the vast majority of speaker designers utilize existing technologies, NSR researches and develops new ones. We are not followers of trends and gimmicks, but innovators in acoustic frontiers beyond the currently known or applied methods. NSR has developed and perfected the “Acoustic Projection Lens” and the physics that supports this acoustic phenomenon.

The "APL," although an outwardly simple device, is quite complex, and has taken nearly a quarter century to perfect. In its theoretical advent (circa 1978), the APL was rationalized as a sonic prism. Originally it was fabricated in an attempt to resolve the perplexing problem of spontaneous frequency emissions from the cone of a transducer, in order to eliminate entropy and correlate these masked emissions by recombining them with the direct wave front of the driver.

The basic mean function of the APL is to redirect a propagated waveform composed of resonant frequencies spontaneously generated from the cone surface, and redirect these emissions in a stimulated spectral waveform through prismatic deviation. The transducer is a mechanical diaphragm reacting to electrical impulse that reacts according to its physical makeup. The diaphragm cannot correlate frequencies and deliver a spectrum of separated, distinct resonant frequency. The net product of implementing the APL technology is a blend of frequencies, reminiscent of white light! All the colors of the spectrum are contained in white light, but are not distinct as a result of spontaneous generation. But thru prismatic deviation, the frequencies contained in the white light being redirected and deviated, are correlated and distinct. The frequency emissions contained are now regenerated in a stimulated spectral array.

Through years of testing and perfecting, it was rationalized that the APL would not complete the equation necessary in home reproduction. Although it achieved its physical task, it was noted that to truly recreate a more dimensional sound field, a baffle mounted driver would have to be implemented. The two speaker components, which could represent by the strings and an instrument body, would have to work in unison with one providing a direct beam and the second deviated beam focused to unveil a more dimensional true stereo sound field. Kodak used this type of process to developing its Kodachrome transparency film. The film held the critical emulsions with distinct color and was fogged with white light yielding brilliant and pronounced color with distinct crispness and edges.I

The low frequency augmenting APL from the D3

In the 80's, several audio engineers rationalized that in order to create true stereo, two point sources in each left and right reproduction unit would be necessary. Just as with the human sight, two distinct elements are requisite to achieve a depth of field. Their devices failed to achieve this task, however, as their short-sighted approach used two identical baffle mounted arrays.

Further studies in acoustics, tone woods, and instrument making have led to more physical abilities of the APL. As a resonance enhancement device, the APL is further complimented by its ability to re-resonate recorded timbre. This is a task that no transducer can perform! Made of instrument grade mahogany, the APL is not braced. Rather, it is tap toned to thickness as a luthier taps a sound board in making a fine instrument.

The NSR Sonic Research Acoustic Projection Lens is truly an instrument; one that re-directs sound from the transducer while trapping proportions of the wave. Our unique and exclusive APL, through its painstakingly engineer shape and construction, allows these proportions to be collected and redirected just as with the body of a guitar or violin. Finally, the APL is built in a fashion and size to optimize the resonance and project the same, in a correlated beam, without loss or breakup!

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Crossover
 

Many loudspeaker crossovers employ technologies such as Zobel impedance compensation networks and/or notch filtering. A Zobel network is an electrical compensation network added to a crossover design to assist with complex driver impedance compensation. Notch filters are band-rejection filters used to compensate for driver shortcomings by passing many frequencies unaltered, but attenuating those in a specific range to very low levels. Both are simply Band-Aids, and as such, are undesirable in a correctly designed crossover. NSR does not employ Zobel networks or notch filtering in its advanced crossover networks.

There are any number of reasons why these technologies are so widely employed  in loudspeaker systems today. Primarily, when the driver, box, and the crossover design chosen simply don’t work, these methods are employed to “fix” or “repair” problems that arose after the design. If a system is designed properly, and the proper combinations of circuitry utilized, these filters should not be required.

Many speaker designers do not build their own crossovers; they purchase them pre-manufactured on printed circuit boards that rob current flow, ultimate dynamics, and add time distortions. Such generic crossovers are obviously not tailored to the system in which it is being utilized. The designer must then include these previously mentioned destructive types of filters in an attempt to shape a standard design into a somewhat more specialized capacity. This type of current control chaos is implemented to try and sustain an inefficient motor and box assembly controlled by a dysfunctional crossover. These filters diminish the sonic quality of the signal and pollute the signal path in the false hope of sustaining a poor motor assembly in a lethargic box system. Beware of any system utilizing such compensation, as they will be sonically inaccurate!

NSR crossovers are hard wired in a symmetrical fashion without sharp turns. A smooth current flow path eliminates losses as opposed to coils and caps soldered to the thin flat pieces of copper tape on a circuit board. Circuit boards are quick and easy, but losses in the signal path are evident. Solid core wire, bound to thin flat tape and back to wire, along with all the sharp turns, creates improper and unbalanced current geometry.  Current cannot squeeze through a maze of filters and then rebound! The losses sustained from this manipulation are clearly audible. 

NSR employs its own handmade 24 or 12 dB per octave networks, based on proven Linkwitz Labs filter design. We further offer two tiers of crossover, one remarable, one reference grade.

The Remarkable crossover uses the highly respected Auricaps and Vishay Resistors, the Erse Super Inductor, as well as other high quality air coil inductors. Or, you can step up to the ultra pure Reference crossover option that employs some of the finest electronic components available from anywhere in the world, including Duelund Carbon Resistors, and a choice of the new Mundorf Silver Oil Gold Capacitors or the superb hand built Duelund Copper Foil Capacitors, and  inductors fabricated using the excellent Solen Hepta Litz.  wiring,  made from a singular audiophile grade multi-strand and multi-gauge copper.

We have ample reason to beleive that our Reference crossover bests crossovers from competing brands costing as much as $30,000 or more.

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