Sansui SP-2500 speakers

3-way, 5-speaker Multi-directional speaker system

Here's a powerful 80 watt speaker system that's as up-to-date as tomorrow when it comes to handling complex sound reproduction chores for the increasingly more sophisticated stereo systems now coming onto the market.. The SP-2500, for example, features a brand new speaker mounting method and unique, curved "Kumiko" hand-carved fretwork grille which contributes greatly to better reproduction of the sound field, a "must" in the New Wave 4-channel stereo that is so rapidly sweeping the stereo world. The new mounting method, in this Multi-Direction (or MD) system, succeeds in recreating inside the listening room the complex interference of sound waves normally present in a natural sound field. This is achieved by angle-mounting certain of the speakers to set up an interference fringe - a whirpool of sound - inside the room, which makes possible a unique effect that cannot be obtained simply by greater sound dispersion. Moreover, this elegantly-crafted hi-fi system also adopts a newly developed mechanical high-cut type woofer which ensures smooth frequency response even at very low frequencies., and a high-performance Loudness Contour type crossover network for distinctly superior damping characteristics, and better transient response.

 

3-Way, 5-Speaker, 80 Watts

The SP-2500 is of a 3-way 5-speaker design, consisting of a 12-inch mechanical high-cut type, high-compliance woofer, a pair of "multi-directional" 5 -inch cone midranges with aluminum dome radiators, a nd a pair of horn tweeters with an acoustic lens (diffuser). Thanks to the use of specially constructed voice coils, the system is able to handle up to 80 watts in power input.

Multi-Directional System

The SP-2500 features a radically new speaker mounting method which establishes it as a Multi-Direction or MD system. By angling the positions of the individual midranges and/or tweeters, Sansui's engineers have succeeded in producing what they call an acoustic interference fringe - a whirpool of sound - within the listening room. The result is an exciting new liveliness or sense of "presence" than was ever before possible, and which is right in step with the new industry trend away from reproduction of sound source points and toward recreation of the entire sound field.

Newly Developed Woofer

The mechanical high-cut woofer of the SP-2500, a unique new Sansui development, ensure a smooth frequency response even at very low frequencies, which in turn results in extremely well-damped rich bass sound. The new design permits the output signal of the amplifier to be directly fed into the woofer, bypassing the crossover network, and thus substantially improving the quality of reproduced sound.

High-Compliance Design

The woofer incorporates a large 145 mm Ø x 18 mm ferrite magnet to achieve stable piston action with superior transient response even in the face of big power inputs. Quality copper wire, aluminum bobbin and a cone of carefully-selected pulp used in the construction help contribute to the woofer's very impressive performance.

Midranges

The Sp-2500 employs a pair of 5-inch cone midrange speakers in Sansui's unique "multi-direction" design. Each has a newly developed concave aluminum dome radiator directly mounted on its voice coil bobbin. This design permits a very smooth transition to the tweeters, with virtually no phase agitation, and helps to improve the diffusion of reproduced sound as well. The voice coil, of expensive copper-clad aluminum wire, moves very smoothly, achieving a flat frequency characteristics and good transient response. Designed to effectively diffuse the radiated heat, each speaker is able to withstand big power input. The speakers are sealed with big-cavity plastic covers lined with abundant acetate sound absorbent to completely prevent interference with the woofer. Frequency response near the woofer crossover is consequently very smooth.

Tweeters

The SP-2500 also employs a pair of horn tweeters. Positioned in a vertical row, they offer a unique "ton saule" effect, while the adjacent sound diffuser achieves an acoustic lens effect. Together the effects substantially improve sound diffusion in the horizontal direction. This naturally adds to the sound field effect afforded by the "multi-direction" design of the midranges, and helps to create a still more lifelike sound field in the listening room. Each tweeter is a unique, new concept horn speaker which cuts short the aluminum die0cast horn and uses only the high-range portion. Though its low-range response extends down to near 2 kHz, it is made responsible only for frequencies over 6,5 kHz. Small wonder the transition to the midranges is so smooth the listener hardly senses the existence of the tweeters. Each tweeter makes use of a 19mm Ø polyester diaphragm to realize pleasant, light and transparent timbre.

 

Newly Developed Crossover Network

The SP-2500 is equipped with a high-performance Loudness Contour type network which utilizes an ideal E-type ferrite core and is designed as a printed circuit board for greater reliability. In addition, it is provided with level controls for the midranges and tweeters/ of a unique 3-step (Soft, natural and Clear) "tap-down" switch design, these permit accurate level control and are relatively free from the faulty contact and performance-deterioration so common to the previous resistor-type attenuators. They permit selecting the tonal quality best suited to the acoustic condition of the room or the listener's preference.

Damped Bass Reflex Chipboard Enclosure

The speaker enclosure adopts a damped bass reflex design, making use of two pipe ducts and combining the advantages of both the air suspension and bass reflex designs. It completely avoids an unnatural increase in sound pressure at low frequencies and unpleasant "cabinet resonance", and offers a flat frequency characteristic and a very low distortion factor. Of solid chipboard, covered with open=pore finished natural walnut, the rugged cabinet is able to reproduce the heavy rich bass of a pipe organ or any other instrument.

Beautiful Curved Kumiko Fretwork Grille

The SP-2500 is graced with a beautiful hand-carved "Kumiko" fretwork grille like other Sansui speaker systems. The difference, however, is that it is curved for still better appearance and a sound diffusing effect. It adds to the decor of the room more than ever.

Pushbutton Connection Terminals

Connections are made almost effortless with the Sp-2500,thanks to the adoption of fool-proof one-touch pushbutton type connection terminals; just push the terminal button, put end wires in opening, and release button. This system also minimizes the possibility of short circuits at the speaker terminals

 

Specifications

Speakers

Woofer :  1 x 300 mm (12")

Midrange : 2 x 125 mm (5") cone-type

Tweeter :  2 x 50 mm (2") horn-type

Power rating:  80 W (Peak)

Impedance:  8 Ω

Sensitivity:  98 dB/1W/1m distance

Frequency Range:  50 - 20,000 Hz (anechoic chamber)

30 - 20,000 Hz (normal listening room)

Crossover Network:  3-way 12 dB/oct parallel type

Crossover Frequencies:  700 Hz; 6,500 Hz

Dimensions (H x W x D):  640 x 425 x 275 mm (25-1/4" x 16-3/4" x 10-7/8")

Weight: 23,3 kg (51,3 lbs)

Finish: Walnut open pore