What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

KEF Cantata SP1056

KEF loudspeakers are designed to reproduce natural sound, free from exaggerated effects of balance and with the lowest possible distortion. Many hundreds of separate items are used to build a loudspeaker system and the electrical and machanicl interaction of the components will significantly affect the reproduction quality

Loudspeaker drive units.
Every KEF diaphragm is manufactured from plastics or, in the case of larger units, from metal and plastics. These special constructions obviate the wide variations in performance associated with ordinary loudspeakers, and considerably reduce colaoration due to the absence of unwanted resonances in the diaphragm itself.
KEF engineers work with radically new techniques to explore the truth about sound coloration, its causes and prevention. Computer based analysis techniques unfold a more precise and detailed insight into speaker behaviour than was previously possible using conventional research techniques.
To make loudspeaker systems which optimise the performance of individual KEF drive units, recent research has concentrated on the interaction of other critical components with the drive units - the dividing network and the enclosure.

Loudspeaker Enclosures
Resonances in a loudspeaker enclosure are known to cause unwanted acoustic radiation which can ruin the clarity of sound from even the finest drive units. The impulse response compares signals from a single drive unit measured in a simple undamped enclosure and from the same unit in a box to which optimum dampinghas been applied using layers of bituminous damping material.
Enclosure analysis is part of loudspeaker engineering. KEF are noe able to assess objectively the audible effect of enclosure resonances and consequently, each KEF system is critically and consistently damped to minimise resonances and reduce audible coloration.

Dividing Networks
Conventional filter designs assume that the load is a simple resistance, whereas in fact, loudspeakers present complicated loads with frequency dependent impedance characteristics. As a result, traditional loudspeaker dividing networks rarely satisfy the conflicting requirements of smooth amplitude frequency response and desirable impedance characteristics.
An entirely new approach to dividing networks has been developed by KEF. The new technique improves transient behaviour giving a smoother, more transparent sound quality, increased depth perspective, and sharper stereo imaging.

System Study
Detailed objective analysis of the comleted loudspeaker system is aided by another sophisticated KEF computer programme. Three-dimensional plots of cumulative spectra - provide "in depth" displays of speaker response in terms of amplitude, frequency and time. At last it is possible to see the effects of speaker design changes and relate them to sound quality.

Quality assurance

The quality of a KEF speaker is under surveillance and control at all stages of production, commencing with the critical inspection of incoming raw materials and components. Frequent inspection of subassemblies at many subsequent stage ensures a very high standard of consistency and reliability. Final testing is carried out using the most sophisticated techniques. Stringent and effective quality controls enable KEF to offer a Five year warranty on all its products.

Specification:  Cantata
System Type:  Three-way, floor standing
Enclosure Type:  Closed box
System:  SP1056
Drive Units: 
Bass Unit :  B139 (SP1044),
Bass  Unit :  B110 (SP1057),
Tweeter :  T52 (SP1049)
Crossover:  SP1058 and SP1064
Input Impedance:  8 Ω
Rated Maximum Power:  150 W programme
Amplifier Requirements:  15 - 150 watts per channel into 8 Ω
System Resonance:  38 Hz, Q=0.7
Frequency Range:  35 - 20,000 Hz, ±3 dB
Sensitivity:  8 watts for 96 dB at 1 m and 400 Hz in anechoic conditions
Crossover Frequencies:  250 and 3000 Hz
Internal Volume:  60 litres
Finishes:   Walnut or Teak
Grille:  Mokka brown cloth
Dimensions (W x H x D):  815 x 340 x 392  mm (32.1" x 13.4" x 15.4")
Weight:  31.7 kg (70 lb)

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