M-Audio EX66, Руководство пользователя

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2 » EX66 User Guide
What’s with the Two Silver
Woofers?
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The EX66 uses a midwoofer-tweeter-midwoofer (MTM) vertical
array configuration to provide an extraordinarily versatile sound
radiation pattern (degrees of arc for the sound wave, vertically
and horizontally). Consider the following: conventional 2-way
speakers in a stereo setup require that you listen to them in a
fairly narrow “sweet spot” (where you position yourself at the
apex of an isosceles triangle with the speakers). By contrast, a
stereo pair of EX66 monitors provides a wide sweet spot, creating
a proper stereo image even when you are not exactly equidistant
from each speaker. This means more people in the room can
benefit from the EX66s’ accuracy and detail without having to
fight for the “money” seat.
Also, while our MTM configuration gives you a wide horizontal
sweet spot, it limits vertical sound diffusion to a cardioid pattern.
This helps minimize reflections off of mixing desks and improves
sound intelligibility. (As near-field monitors are often positioned
on top of mix consoles, there is a persistent problem of early
reflections off the desk surface which can “smear” sonic details;
the EX66 vertical axis rejection characteristic greatly reduces this
problem.)
Finally, we designed the woofers from a state-of-the-art material
that happens to be a nearly perfect reproducer of sound. Our
drivers have exceptional intrinsic damping characteristics and
absolutely no frequency response peaks (resonances) in the
audible band. They provide truly linear pistonic action over the
entire musical spectrum, revealing more of music's subtle details,
and bringing all portions of each musical transient into correct
alignment. But don’t just take our word for it—as the old proverb
goes, “the proof of the pudding is in the eating.” In other words,
listen for yourself!
Did You Know...?
...that our drivers can withstand extreme
temperatures, moisture, humidity, sunlight,
and salt? The material we use to make our
EX-series cones is very similar to that employed
by NASA scientists to form heat shields for
Space Shuttle orbiters.
Other Noteworthy
Characteristics
Titanium Tweeter
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We’ve discussed the woofers in some detail, but of equal importance
is the high-frequency driver. Our 1” tweeter sounds as smooth as
it looks. Titanium is known in the aerospace industry for its high
tensile-strength-to-weight ratio and its resistance to corrosion.
We made our tweeters out of titanium in order to create a stiff,
yet responsive piston that moves natural resonant modes well
above 20kHz, allowing the tweeters to track every nuance of
musical detail as accurately as possible, without smearing any high-
frequency energy. We designed and tuned these custom tweeters
to sound crisp and transparent, without the harshness sometimes
associated with rigid high-frequency drivers. The result is a natural
complement to the low-frequency drivers, providing smooth,
coherent reproduction over the entire audio band.
Bass-Reflex Port
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Many loudspeaker enclosures use an air vent (or port) to form
a Helmholtz resonator, which improves bass response. In some
ported speakers, however, you can hear friction noise from air
moving in and out of the enclosure—but not here. We developed
a rear-cabinet port with dual flanges to minimize the vibrations
normally generated by low-frequency signals. This custom port
is extremely efficient in its air transfer characteristics and it is
virtually noise-free.
Enclosure
Like the other components, the EX66’s enclosure has an important
role in shaping the overall sonic response. In order to provide
more stable performance, we designed an enclosure made of a
special high acoustic efficiency medium density fiberboard (MDF)
and unique interior reinforcement designed to absorb vibration
and impact generated under extreme conditions. Further,
our custom-designed waveguides on the front panel minimize
diffraction and improve stereo imaging.
Digital Signal Processing
All mechanical and electrical systems are inclined to vibrate
(or resonate) at certain frequencies when excited by external
forces. For loudspeaker cabinets, resonances can be a particularly
insidious problem because they color the timbre of the music.
The human ear/brain mechanism is capable of perceiving even
extremely subtle resonances, and it’s this phenomenon that
allows critical listeners to distinguish easily between exceptional
loudspeakers and mediocre ones. At M-Audio, we decided to
address the problem of cabinet resonances with a novel yet highly
effective solution.
The EX66 contains sophisticated digital signal processing (DSP)
technology to tune the cabinet and crossover with exceptional
precision. The EX66 eradicates all resonances from the cabinet
by using IIR (infinite impulse-response) filters in its on-board
processor. The EX66 also uses DSP to achieve its precise and
maximally flat 4th-order Linkwitz-Riley crossover.
Bi-amped Efficiency
The EX66 uses two separate 100-watt PWM power amplifiers to
drive the 4
Ω woofer combination and 4 Ω tweeter separately in a
high-end bi-amp structure. The ultra-low distortion at 200 watts
per channel rounds out the EX66’s profile as a truly world-class
active loudspeaker monitor.
Versatile Connectivity
We’ve provided high-impedance (20 k Ω ) balanced XLR
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and
TRS
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analog inputs as well as 110 Ω AES/EBU (AES3
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) and
75 Ω (S/PDIF
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) digital inputs—all to give you maximum flexibility
in your connections. The digital inputs automatically detect the
bit depth and sample rate of the incoming signal and can lock to
incoming clocks up to 192kHz and with 24-bit resolution—all with
the lowest jitter specs in the industry.