Gradient Revolution Brochure

REVOLUTION

NEW

MODEL

Revolution revised

New woofers together with crossover coils wounded of thicker copper

rise the system´s sensitivity. There are also new polypropylene capacitors

of highest quality. Otherwise the construction has remained the same.

Gradient REVOLUTION is an unique combination of the best properties of a big

panel loudspeaker and a small nearfield monitor. From this starting point it has been

developed a loudspeaker concept more insensitive to the room

than any other loudspeaker in the World.

The net result is an outstanding musical reproducer, a loudspeaker which lets

the walls disappear and flies you to the concert hall.

DIPOLE BASS

The bass part of the Gradient Revolution loudspeaker
consists of two 30cm custom made long throw woofers.
They are assembled on an open baffle giving the low
frequencies a "figure eight" or dipole radiation pattern
similar to most panel loudspeakers. These two woofers
operate from below 30Hz up to 200Hz.
An ordinary box speaker radiates in all directions at low
frequencies. This has the unfortunate effect of generating
standing waves in all dimensions. In a typical listening room,
standing waves distort the sound at frequencies below
200Hz.
The Gradient Revolution does not excite standing waves
between the floor and the ceiling, it can only generate
them in the direction of the radiation pattern.
The woofer section of the Revolution can be rotated and
directed in three different ways, to minimize undesirable
standing waves in the listening area. This ability to "tune" out
standing waves in the bass is quite unique. The result is a
smooth articulate bass response which has correct musical
pitch and dynamics.

ONE POINT SOURCE

Frequencies over 200Hz are reproduced by a coincident
driver assembly. A 18cm fibreglass cone handles
frequencies up to 2800Hz. High frequencies from 2800Hz to
over 20kHz are reproduced by a 25mm 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.

COAXIAL CARDIOID

The midrange driver is mounted in an acoustic resistance
enclosure giving the system a cardioid (heart shape)
radiation pattern. The dome tweeter uses the cone of the
midrange driver as a wave guide thereby providing the
same cardioid pattern.
From 200Hz up, the speaker radiates sound mainly in the
forward direction. The rear radiation is effectively damped
by having a power ratio of 100 to 1. This minimizes any early
reflections when the speaker is placed against the back
wall. Special attention has also been taken that the
radiation patterns are consistent at all frequencies.
The design of the speaker also minimizes sound reflections
from the cabinet itself and nearby boundaries, thus
negating the effects of diffraction. The room influence to
the sound remains very small, especially at mid and high
frequencies giving the Revolution a very similar sound
characteristic in different rooms.

FLAT ENERGY RESPONSE

The frequency response of the Revolution at the listening
position is extremely flat; but this alone is not sufficient for
Gradient. Every speaker radiates at least some sound in all
directions. If the energy response of a loudspeaker has
peaks and dips, the reverberant sound field will be uneven,
colouring the music. Frequency response measured in all
directions must be linear - as with the Revolution - in order
to ensure linear energy response.
The editor of American Stereophile magazine (Vol.20 NO.3)
measured for the Revolution a flat room response of 33Hz ­10kHz +/-1.3dB (!) in his living room.

MANY POSSIBILITIES FOR ROOM POSITIONING

different ways allowing for unique control over unwanted
standing waves.
If a panel speaker is positioned near the rear wall the bass
output will be attenuated strongly and the midrange will be
coloured by early reflections. The Gradient Revolution
overcomes both of these problems. When positioned
against the wall the bass section will be faced toward the
adjacent wall. The bass can be attenuated by increasing
the distance from the rear wall and fine tuned by rotating
the speaker a few degrees.
Due to the radiation pattern at middle and high
frequencies, unwanted early reflections are not created.
The music remains smooth and open with correct timbre as
with conventional panel speaker positioning.

TERMINALS AT THE BOTTOM

Rotating the bass section of the speaker for different
positioning in the room has no influence as to the
appearance of the speaker. Terminals are on the bottom of
the speaker so the cable(s) can be positioned in any
direction. There are four terminals for bi-wiring or bi-amping.

RAVE REVIEWS

Gradient Revolution has been a success everywhere in the
World. Ask a summary of reviews by leading HiFi and High
End magazines.

Technical specifications

Radiation patterns: bass: dipole

midrange & treble: cardioid

Frequency response: 50...20000Hz +/- 2dB, -6dB @ 30Hz
Impedance: 6 Ohms, minimum 5 Ohms
Sensitivity: 87dB/2.83V/1m
Recommended
amplifier power: 50...250 W
Drivers: 2 x 30cm long throw woofer,

176 mm fibreglass midrange,
coaxial aluminium dome 25 mm

Crossover
frequencies: 200 and 2800 Hz
Connections: two pairs of binding posts.
Finish: solid cherry or black
Dimensions (WxHxD): 41 x 102 x 36 cm
Weight: 24 kg

Manufacturer: Gradient Ltd

Levysepänkatu 28
FIN-04440 Järvenpää
Finland
Tel. [phone]
Fax [phone]
www.gradient.fi

Your Gradient dealer:

The Gradient Revolution can be positioned in the room like
a panel (dipole) speaker. In this case one or two metres
from the rear wall is beneficial. Unlike panel speakers, the
bass section of the Revolution can be directed in three