Gradient Evidence Mk3 Brochure

EVIDENCE MK III

New Model

A new woofer and a new coaxial driver together with a new crossover circuit

make this old war horse sound brand new.

Our design is based on the same unique principle as Gradient's flagship the

Revolution. Main part of the audible frequency range is covered by an one-point

driver system. The coaxial driver is assembled in an acoustic resistance box

giving the system a radiation pattern of cardioid. This technique has

many benefits over conventional constructions.

The Evidence MK III shows that a HiFi loudspeaker can be easily positioned

into the room and even against the wall without sacrificing the sound quality.

The Gradient Evidence MK III will produce high performance sound

in any placement.

PROBLEMS WITH CONVENTIONAL SPEAKERS

ALSO FOR HOME THEATRE

Any loudspeaker with drivers assembled on the front of
the cabinet will radiate sound to all directions at low and
mid frequencies. If the cabinet is positioned near or
against the wall the backward radiation will cause
reflections reaching the listener immediately after the
direct sound. These early reflections colour the mid
frequencies and deteriorate imaging and sound stage
accuracy. Also the perceived bass level varies strongly
depending on position.

GRADIENT'S SOLUTION

Gradient has studied this problem and offers an unique
solution. The Gradient Evidence MK III has a special
acoustic resistance enclosure to reproduce frequencies
above 200 Hz. In practice this means that the speaker is
not at all radiating sound backwards. The backward
radiation of the Gradient Evidence MK III is attenuated by
20 dB at mid frequencies which is only one percentage of
the total sound energy. Thus the early reflections are
minimized when the speaker is positioned against the
back wall or nearby boundaries.
The design of the speaker also minimizes sound reflections
from the cabinet itself, thus negating the effects of
diffraction.
In a nutshell: the room influence to the sound remains
very small especially at mid and high frequencies giving
the Evidence MK III a very similar sound characteristic in
many different rooms.

ONE POINT SOURCE

The coaxial driver reproducing frequencies over 200 Hz is
positioned on the top of the front wall of the speaker
cabinet. A six inch fibreglass cone handles frequencies
up to 2800 Hz. High frequencies from 2800 Hz to over 20
kHz are reproduced by an one inch aluminum dome
tweeter placed at the apex of the midrange cone.
A point source is generally accepted as an ideal sound
source for its excellent phase and amplitude response.
This results in an extremely accurate, stable and three
dimensional sound stage.

BASS DOWN TO 30 Hz

Low frequencies below 200 Hz are reproduced by a
bassreflex enclosure tuned at 28 Hz. The reflex tunnel is
part of the cabinet thus giving extra strength to the
construction. The bassreflex opening is at the rear above
the terminals. Large cross section area guarantees no
breathing noise even at high sound levels.

THE BASS LEVEL ADJUSTMENT

The bass level adjustment is a very useful feature when
positioning the speaker near or against the wall.
The Gradient Evidence MK III is equipped with a two
position bass level adjustment. This allows the listener to
adjust the correct level depending on the placement of
the speaker but also on personal taste.
The level of bass relative to the mid and high frequencies
is easily adjusted by a jumper near the terminals.
There is a third position, too: removing the jumper makes
the speaker sound brighter. Worth of trying when listening
at low volume.

The Gradient Evidence MK III loudspeakers are designed
for the most demanding audio enthusiasts. However there
are good reasons to use them as main loudspeakers in a
home cinema system.

BACKWALL INFLUENCE TO FREQUENCY RESPONSE

Technicqal specification

Radiation patterns: sphere (bass),

cardioid (midrange & treble)

Frequency response: 45...20000 Hz +/-2 dB, 29 Hz -6 dB
Impedance: 4 ohm
Sensitivity: 86 dB/2,83 V/1m
Drivers: 1 x 200 mm (8") long throw

woofer,

1 x 176 mm (6 1/2") fibreglass

midrange

1 x coaxial aluminium dome

25 mm (1")

Crossover frequencies: 200 Hz and 2800 Hz
Connections: Bi-wireable. Thick cable

(up to 30 mm2)
or 4 mm banana plugs or
forks will work.

Finish: solid cherry or maple or black

painted cherry

Features: Bass level adjustment, 3 dB
Dimensions (WHD): 21 x 100 x 30 cm
Weight: 22 kg

Manufacturer: Gradient Ltd

Levysepänkatu 28
FIN-04440 Järvenpää
Finland

Telephone [phone]
Fax [phone]
Email [e-mail]
Internet www.gradient.fi

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