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I like the futuristic styling of the Reference 3.1s, as does my
wife, so we preferred to have them on display. I also like the smaller
apparent size of the speaker without the grille. The Reference 3.1 is not a
large speaker, which is one of the things that make it attractive to me. It
stands only 36" tall and is a mere 8" wide by 14" deep, but its pillar and
separate enclosure design make it seem even smaller.
The back slanted MDF pillar, combined with longer spikes in the front of the
base help to time align the system. As mentioned earlier, the Reference 3.1s
use almost no crossover. The only crossover in the speaker is a low pass
filter used to limit the high frequency extension of the woofer to 125 Hz.
Neither the midrange nor the tweeter use a crossover, instead relying on the
acoustical properties of the enclosure and driver to define their bandpasses.
This design minimizes the negative effects of the crossover on the musical
signal. Crossovers are filters, and are therefore purely reactive circuits.
Reactance is a way to describe energy storage in an electrical circuit. Its
counterpart, resistance, describes the dissipation of energy in a circuit.
Resistance just turns electricity into heat, and does not affect the time
response of a speaker, but reactance is a completely different kettle of
fish. In changing the frequency response of a speaker, a crossover stores up
energy and then releases it over time. It is the fundamental nature of the
crossover that it will alter the time response of a speaker. While the crossover-less design of the Reference 3.1s does not eliminate reactance
above 125 Hz (the drivers themselves present a reactive load), the design
goes a long way towards a time coherent system without the use of
complicated electronics in the signal path. Their sensitivity is a modest 88
dB/w/m. While likely not in the single digit wattage SET amplifier
regime, the Reference 3.1s should be fairly easy to drive with most solid
state or tube amplifiers.
As I alluded to before, the two pairs of binding posts on the Reference 3.1s
are not for bi-wiring, but for a novel version of bi-amping that can extend
the low frequency performance from a respectable 34 Hz to a stupendous (for
a 47 lb 36" tall loudspeaker) 22 Hz. The 10" woofer in the Reference 3.1 is
a dual coil driver, meaning that there are two independent voice coils
attached to the driver inside a single magnet. One of these voice coils is
driven via the top pair of binding posts with the full range signal through
the low pass crossover, as in a traditional speaker. The bottom binding posts
drive the second voice coil directly, and are meant to be used exclusively
with an outboard subwoofer amplifier and crossover. With this second
amplifier and crossover tuned properly, the speaker's low frequency response
can be extended by almost a full octave. It is essential, however, that this
subwoofer amplifier be equipped with a low pass crossover, otherwise the amp
will attempt to drive the woofer with a full range signal, resulting in
terrible performance above the woofer's 125 Hz maximum design frequency.

The Gallo Reference 3 S.A. amplifier was designed specifically for this
mission, although it can be used to drive any non-powered subwoofer as well.
The output power level is 240 watts RMS x 2, and it offers one of the most complete
set of adjustments available to properly tune the performance of the
Reference 3.1 woofers or separate subwoofers.
The crossover frequency is
continuously adjustable from 40 Hz to 180 Hz. The phase is also continuously
adjustable from 00 to 1800 for the left and right speaker
independently. Gain controls are independent for left and right speakers,
making tuning for oddly shaped rooms of asymmetric speaker positioning
possible. Both low level (RCA) and high level (five-way binding post) inputs
are available, as well as a low level "subwoofer" input which bypasses the
crossover controls for use with the bass management features of a surround
sound processor. The amp is also bridgeable to mono with 650 W available
into 4 ohms.
The very solidly built rack mountable unit weighs in at 42
pounds. An unobtrusive thermostatically controlled fan passes air over
internally mounted heat sinks, and both a signal sensing option and remote
trigger allow the amp to be automatically turned on if desired.
The
Reference AV Center Channel Speaker is a new addition to the Gallo line, bringing the high
performance of the Reference 3.1 to a home theater application. The speaker
is built on the same model as the Reference 3.1, combining four of the 4"
carbon fiber midrange drivers in their independent spherical enclosures with
a modified version of the CDT II ribbon tweeter.
The two outer drivers are
used as woofers, with low pass crossovers that limit their operation from 55
Hz to 100 Hz. The center pair of drivers is used full range as in the
Reference 3.1, with the high frequencies limited to 3 kHz acoustically.
The
CDT II tweeter has had its horizontal dispersion limited to 1200. The
five drivers are mounted on an aluminum cross-member, housing the binding
posts and electronics. A perforated metal grille covers the drivers. While
this grille is removable, the speaker is meant to be used with the grille on at
all times. This speaker can be directly mounted on the wall below a flat
panel display, or used with an optional stand. This cast aluminum stand is
very sturdy, and allows adjustment of the speaker for vertical tilt. The
loudspeaker is built to the same very high standards as the Reference 3.1,
using the same drivers, sub-enclosures, binding posts, and construction
techniques. It makes an excellent visual compliment to the 3.1s, while not
taking up a huge amount of space, as do many other center channel speakers of
this performance and price class.
Click Here to Go to Part III.
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