Sansui SP-3500 speakers

4-Way 6-Speaker Multi-Direction Speaker System

Perhaps the most timely speaker system ever introduced, this new 100 watt Multi-Direction (MD) system takes you beyond the reproduction of sound source points to an incredibly lifelike method of reproduction approximating that of an original sound field. This makes the SP-3500 the foremost system available today for the new age of 4-channel stereo. The secret to the SP-3500's living sound lies in its MD System, a new way of angle-mounting speakers within the enclosure to re-create within the listening room the complex interference of sound waves present in the original sound field. All six of the SP-3500's speakers, including a newly developed 14-inch woofer, were specifically selected to achieve this effect. Even Sansui's famed Kumiko fretwork grille has been redesigned in the SP-3500.. It now is gracefully curved to add to the over all elegance of this new system.

 

4-Way, 6-Speaker, 100 Watts

The SP-3500 is of a 4-way 6-speaker design, consisting of a large 14-inch high-cut type, high-compliance woofer, a 4-1//2- by 2-inch horn midrange with a sound diffuser and pair of "multi-directional" 4 -inch cone midranges with aluminum dome radiators,

Plus a pair of 2-ich MD system horn tweeters for the highs. Thanks to the use of specially constructed rugged voice coils, the system is able to handle up to 100 watts in power input.

 

Multi-Directional System

This is a new way of mounting individual speaker units inside a speaker system, to better reproduce in your own room the exciting liveliness or sense of "presence" experienced in a concert hall or jazz club. The MD System is based on increasing the interaction of sound waves by criss-crossing the sounds emitted by the individual speakers. This result in a unique sound field effect unobtainable by simply widening the dispersion of sound. In the MD System, midrange and tweeters are angle-mounted so that they produce an acoustic interference fringe - a whirlpool of sound - inside the listening room.

 

Newly Designed Woofer

The newly developed high-cut type woofer of the SP-3500 permits the output signal of the amplifier to be fed directly into the woofer, bypassing the crossover network. The result is a very smooth frequency response even at very low frequencies, which in turn results in extremely well-damped rich bass sound. This special design is unique with Sansui. Another outstanding advantage of this woofer is found in its high Compliance. The woofer achieves a stable piston action with superior transient response even in the face of big power inputs. Quality copper coil, aluminum bobbin, and a cone of carefully selected pulp help to improve the speaker's frequency response as well as its sound diffusion at extremely low frequencies.

 

Horn Midrange

Sansui engineers have placed a lot of emphasis on the midranges - those important frequencies where the vast majority of musical instruments perform - in the SP-3500. one of the speakers used is a 4-1/2- by 2-inch midrange for the frequencies from 2,000 to 6,500 Hz. While the cut-off frequency of this speaker is set as low as 800 Hz, it is intentionally used in the higher frequencies to eliminate the obnoxious metallic feeling unique to a horn speaker. A short-cut, exponential type die-cast from aluminum, this speaker is fronted with a sound dispersion characteristics. It also utilizes a 25 mm diameter titan diaphragm for top timbre qualities.

 

Cone Midranges

Two 4-inch cone midranges are mounted at an interior angle of 15 degrees to the front as a part of the SP-3500's MD System. Together with the horn midrange speaker, they handle the midrange sound in an "acoustic staggering system" for greater depth and richness of reproduced  sound. Each of the cone speakers has a newly developed concave aluminum dome radiator directly mounted on its voice coil bobbin. This permits a very smooth transition to the tweeters with virtually no phase agitation, and helps to improve the diffusion of reproduced sound as well. Designed to effectively diffuse radiator heat, each speaker is able to withstand big power input. The rear of each speaker is sealed with big-cavity plastic covers lined with abundant acetate sound absorbent to completely prevent woofer interference.

 

Tweeters

The SP-3500 also employs a pair of horn tweeters. Positioned just like the cone midranges, the two achieve the excellent sound dispersion qualities unique to the MD System. Each tweeter is a new concept horn speaker which is responsible only for frequencies over 6,500 Hz. Transition to the midranges is exceptionally smooth. Each tweeter make use of a 19 mm diameter polyester diaphragm to realize pleasant, ight and transparent timbre.

 

Newly Developed Crossover Network

The SP-3500 is equipped with a high-performance Loudness Contour type network utilizing an ideal E-type ferrite core and 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.

 

Bass-Reflex Type 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. Manufactured of solid chipboard, covered with open=pore finished natural walnut, the rugged enclosure is able to reproduce the heavy rich bass of a pipe organ or any other instrument.

 

Curved Kumiko Fretwork Grille

The SP-3500 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-3500, 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 350 mm (14")

Midrange 1  : 2 x 100 mm (4") cone-type

Midrange 2 :  1 x 100x50 mm (4" x 2") horn-type

Tweeter :  2 x 50 mm (2") horn-type

Power rating:  100 W (Peak)

Impedance:  8 Ω

Sensitivity:  100 dB/1W/1m distance

Frequency Range:  40 - 20,000 Hz (anechoic chamber)

25 - 20,000 Hz (normal listening room)

Crossover Network:  4-way 12 dB/oct parallel type

Crossover Frequencies:  700 Hz; 2,000 Hz; 6,500 Hz

Dimensions (H x W x D):  640 x 450 x 2905 mm (25-1/4" x 17-3/4" x 11-7/8")

Weight: 26,4 kg (58,1 lbs)

Finish: Walnut open pore