The Logitech Xtrusio Speakers
Introduction
Logitech
usually evokes images of input devices--joysticks, keyboards, mice and the
like. Recently, they have become a force to reckon with in the computer audio
department. The soon to be released Xtrusio represents Logitech's best effort
to date. This is a full size (nearly 6 inches) subwoofer in a metallic trash-can
like enclosure.
Sporting
six amplifiers, four channels feed the satellites and the remaining two amps
feed the dual voice coil sub. A patented new feature, dubbed LIMAD (Linear
Magnetic Drive) claims to, "provide output at all frequencies in proportion
to input, and to accommodate sudden changes in frequency without distortion."
There is a mouse-like device that controls the volume, front to rear fade
and standby/on modes. While the sub $180 USD ticket isn't the most expensive
bracket for speakers, a growing percentage at this price level have Dolby
Pro Logic decoding. The Xtrusio's do not. Thanks goes out to Logitech for
the editorial sample.
Factory
Specifications
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Logitech
Xtrusio
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- Power Output:
100 Watts RMS @ 10% THD
- Frequency
Response: 28Hz-20KHz
- Crossover
Frequency: 160Hz
- 4-channel
capability
- Input Sensitivity:
130mV max
- Input Impedance:
10Kohm
- S/N : >80dB
- Warranty:
2 Years
- List Price:
$179.95 USD
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Description
& Specifications
The subwoofer
unit is one of the heaviest beasts I ever tested. Weighing in at 12 lbs.,
the apparent heft is quite a welcome change from many of the welter weight
cheap plastic enclosures that seem to dominate the market. The 150mm driver
is a dual voice coil unit, which means two amplifiers can send outputs to
its coils at the same time. The
four satellites each contain a single 57mm driver--no tweeter in this setup.
Logitech
is one of the few manufacturers following a new trend--rating their amp output
at very high distortion levels. In this example, a 10% spec was touted to
allow the opamps to reach the magic three digit mark of 100 watts. With the
exception of the "boomer" cars, ten percent THD (total harmonic
distortion) is totally unlistenable. The midrange -cracks- unbearably and
the lows rumble incessantly as the cone material violently twists out of shape
in the useless attempt to reproduce sound beyond its capability. What's next?
300 watts at 100% distortion? Does anybody think that power ratings make for
great sound in and of itself? Arrrgh!
The power
supply may indeed be the biggest frown maker. A switching unit instead of
a proper analog (linear) one, I had serious doubts before the power switch
was ever turned on. What's so bad about a switching supply you say? Well,
in a computer supply (which all have been switching units for over a decade),
extra parts on the motherboard, such as capacitors and inductors, filter out
the generally horrible hash and garbage that ride atop a moderately "dirty"
DC voltage. If that isn't bad enough, switching boxes also generate a high
frequency hash that varies with load conditions. For example, if you could
"hear" the HF screeching at low current draw, it would increase,
possibly several octaves, into the Megahertz (MHz) range at maximum load.
Think: an RF generator similar to an AM radio station is inside the Xtrusio's.
Hmmmm.
Objective
Measurements
Data acquired
and reported of this type is done without any opinion or bias whatsoever.
For a quickie brush up course on audio terminology and measurements, point
your browser to the Audio
Reproduction Systems article.
Subwoofer
Woofer
Impedance
Frequency
(Hz)
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Voltage
(mV)
|
Current
(mA)
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Impedance
(Z)
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75
|
334
|
43.3
|
7.71
|
100
|
333
|
46.9
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7.10
|
125
|
335
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48.2
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6.95
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