Gradient Revolution Active Brochure

REVOLUTION

WITH ACTIVE CROSSOVER AND ADDITIONAL BASS SECTIONS

If you listen to the bass section of the Revolution alone you will be surprised to find

how little information there really is under 200 Hertz. However the quality and quantity of this

information affects strongly to the subjective listening experience. Too much bass will decrease

the accuracy and deteriorate the feeling of space, too little makes the sound thin and tiring.

The real low frequency properties of a sound recording will be reproduced most

convincingly by a dipole bass system giving the radiation pattern of eight. You can easily hear

the minute tone nuances and follow the bass lines. When compared to the conventional

closed box or bass reflex systems you will get the same sound pressure level at only one third

of acoustic energy. Thus the room colouring effects are much less annoying and

your neighbour will hear less of your bass lines.

Otherwise excellent system the dipole bass has one drawback, how to get high volume and

how to reproduce the lowest notes.

Happily Gradient has solved these problems in the Active version. Hi-Fi enthusiasts have now

unprecedented possibilities to fine tune the bass response both in quality and quantity.

POWER AMPLIFIERS ACCORDING TO YOUR TASTE

You can freely make your own choice of amplifiers to power
the "Active" Revolution loudspeaker system. Signal coming
from a sound source or a preamplifier is fed to the active
crossover, and it is divided there into two parts to run two
power amplifiers.
For the bass section it is recommended to use solid state
amplifiers because of their low output resistance at low
frequencies giving good control over the woofers.
For the upper part of the spectrum (over 200 Hz) valve
amplifiers will do as well.

ACTIVE DIPOLE CORRECTION

Due to the open construction of a dipole bass (without an
enclosure at all) the frequency response will roll off at 6 dB
per octave. The roll off point is higher than that of a closed or
bassreflex box and needs equalization. In the standard
version of the Revolution this is made in the passive crossover
circuit. However the laws of physics and the actual size and
price of components do not allow to extend the
reproduction to the very lowest notes. However this is easily
done in the active crossover. The lower limit of the Active
version is set to reach to 20 Hz, -3 dB.

OTHER BENEFITS

The number of passive crossover components is minimized in
the Active version. Only the crossover between mid and
treble drivers is carried out by passive components.
The woofers are directly connected to the power amplifier
giving the best possible control over the cone excursion.
Thanks to the active bass level control the sensitivity of the
mid driver and tweeter can be fully utilized without
attenuating them as in the passive version.

NEED FOR ADDITIONAL BASS UNITS

Experiences in various rooms have proved to be true, that the
need for additional bass units seldom occurs. When listening
at high sound pressure levels in large and well damped
rooms extra bass units will give more headroom and reduce
the distortion.
Doubling the number of woofers will give 6 dB more
headroom. It is possible to add any number of bass sections
to the system.

FROM PASSIVE TO ACTIVE ONE

Every passive Revolution can be modified to the Active one.

ACTIVE CROSSOVER

The crossover designed by Gradient is carried out following
the best High End principles. The layout of parts and printed
circuits made of high quality components are situated in a
solid metal housing so that both external and internal
magnetic and electrical interferences are eliminated. For
instance the power supply is positioned far away from the
small signal sections. The components used have passed the

golden ear designer's tests, to mention only Burr-Brown's
operational amplifiers.

ALSO BALANCED

The crossover is equipped with both balanced XLR and
unbalanced RCA connections to suite every audio system.
Desired type is selected by a switch.

BASS LEVEL CONTROL

The level of bass can be adjusted continuously by a knob at
the rear panel. According to the personal taste and listening
room acoustics the bass is easy to adjust. Once found the
correct balance, there is little need for further adjustments.

STEREO/MONO SWITCH

When playing warped LPs the cartridge tone arm system
may give rise to high level subsonic frequencies which cause
excessive cone excursion and take a lot of unnecessary
power from the amplifier. Mono operation of bass channel
will eliminate this.

Q-VALUE ADJUSTMENT

Terms fast and slow bass are often used by experts when
speaking about the quality of bass response. The Gradient
Research Group studied the problem and solved it.
The crossover includes a three position toggle switch to
adjust the Q-value.

TECHNICAL SPECIFICATION

Active crossover
Amplification: 6dB/balanced;

0dB/unbalanced
Bass level adjustment: +/-10 dB
Crossover frequency: 200 Hz
Dimensions,WHD: 430x108x390 mm
Housing: Brushed aluminium,

stainless steel
Weight: 9,6 kg

Manufacturer: Gradient Ltd

Levysepänkatu 28

04440 Järvenpää

FINLAND

tel. [phone]

fax [phone]

www.gradient.fi