Chorale III is a
very compact 2-way bookshelf loudspeaker which, despite its being unobtrusive,
nevertheless produces the full-bodied detailed sound quality associated with
larger KEF loudspeakers. Styling is simple and uncluttered with front baffle
graphics for those who prefer to listen with the grille removed.
Efficiency is in the
medium to high range at 87 dB/W/m and the output from a 60 W amplifier can be
handled safely under audiophile conditions.
The design of small
loudspeakers is actually more difficult than for larger models. Every parameter
is more critical and only a "complete system" approach is likely to
be successful. The performance of each component must be studied first in isolation
and then in relation to the others because drive units, dividing network and
enclosure all react together to produce a musically integrated sound.
Through careful
optimisation of drive unit parameters effective bass output extends below 50 Hz
which is more than adequate for domestic applications. Low frequency characteristics have been determined so that
natural sound balance will be obtained when the loudspeaker is placed with its
back to a wall.
KEF system design
techniques are completely vindicated by Chorale III. Computer optimisation
programmes, listening tests and production quality control combine to produce a
loudspeaker which offers astonishing performance in relation to its size and
price.
Cabinet work is
finished in top quality simulated walnut with brown textile grille.
KEF Chorale III is
perfectly suitable to reproduce compact disc and other types of digital
recording with full dynamic range.
The unobtrusive
appearance of Chorale III belies the tight, integrated sound which comes from
this small box. The carefull integration of bass and high frequency performance
is achieved through a deceptively simple 7 element dividing network, skilfully
designed using computer techniques.
The bass/midrange
unit is fitted with a magnet system much larger than that frequently found in
speakers of this size and price, thus affording the degree of control necessary
to avoid "boom" in a speaker which is likely to be used on a shelf or
close to a wall.
This deive unit has
a nominal diameter of 160 mm, with a plastics coated fibre pulp cone and PVC
roll surround. The ywo-layer 25 mm voice coil is bonded with high temperature
resins to reduce risk of burnout.
With a nominal
diameter of 30 mm, the impregnated textile dome high frequency unit is driven
by a two-layer voice coil 25 mm in diameter. The air gap is filled with a
special Ferrofluid which, by keeping operating temperatures lower, reduces
variations in high frequency level at high volume caused by temperature related
compression effects.
The cabinet is
constructed from high density chipboard, providing bass loading with 9,4 litres
of air in a sealed enclosure. Drive unit and cabinet parameters are carefully
matched to optimise low frequency performance.
Chorale III is
finished in simulated walnut high quality PVC foil with the grille board
covered in a brown knitted textile.
Specification: Chorale III
System Type: Two-way, bookshelf/stand-mount
System SP3021 Drive units:
B160 bass unit
(SP1094),
T33 tweeter (SP1089)
Crossover: SP2029
System SP3022 Drive units:
B160 bass unit
(SP1095),
T33 tweeter (SP1089)
Crossover: SP2030
Nominal
Impedance: 8 ohms
Rated Maximum
Power: 50 W
Directional
Characteristics (within 2dB of response on reference axis)
Vertically : up to 20 kHz for ±5°
Horizontaly : up to 12 kHz for ±20°
Frequency
response: 79 Hz to 20,000 Hz, ±3.0 dB at 2m on design axis
Sensitivity: 87dB spl at 1m on
reference axis for pink noise input of 1W
Distortion (Measured at 1m on reference axis at mean spl
of 90dB, anechoic conditions)
Second
harmonic : less than 1% from 170Hz
to 20,000 Hz
Third
harmonic : less than 1% from 80 Hz to 20,000 Hz
Maximum output: 105 dB on programme peaks under typical
listening conditions
Enclosure Type: Closed box
Internal
Volume: 9,4 litres
Finish: Simulated
Walnut Veneer
Grille: Brown fabric
Dimensions (H x W x
D): 370 x 220 x 180 mm (14.5 x 8.7 x 7.1
inches)
Weight: 4.7kg (10.4 lb)
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