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Setting up the Rubicon R8a
BackgroundontheRubiconR8aStudioReferenceMonitor
The Rubicon R8as' are self-powered, near-field reference monitors, featuring robust power, advanced electron-
ics and custom designed drive units. For pristine highs, the Rubicon R8a boasts a 1-inch by 2-inch velocity rib-
bon tweeter. The Rubicon ribbon tweeters are constructed using a Kapton diaphragm with vaporized alumi-
num applied to the surface. The diaphragm is then set between an array of neodymium magnets creating an
opposing magnetic field. Since the ribbon is both the coil and the diaphragm, the diaphragm can accelerate
and decelerate quickly resulting in un-matched transient response. Unlike conventional dome tweeters, the
ribbon tweeter exhibits no coloration due to resonance, as well as, extremely low intermodulation distortion.
The result is a wide, linear response producing high frequencies that are sweet, while clear and accurate. For
the low frequency response, the R8a employees an 8-inch, copolymer, low frequency drive unit with butyl
rubber surround. The woofer is well matched to the tuned enclosure and provides punchy and focused bass
frequency response.The monitor’s crossover has been carefully designed with high quality components insur-
ing a linear frequency and phase response. The Rubicon R8a enclosures are constructed from MDF (Medium
Density Fiberboard) and are finished in scuff resistant, textured paint. The monitor’s enclosure also includes
a tuned vent port that provides extended low-end response, and with a low turbulence design, the low fre-
quency driver can move freely with minimal effect on the overall impedance. On the rear of the enclosure,
you’ll find the Rubicon R8a control panel, which features a variety of input connections including both XLR
balanced input, and a1/4-inch TRS balanced input plus an RCA unbalanced input. These inputs are connected
to Rubicon R8a’s internal active crossover and bi-amp power module providing 75 watts of power for the low
frequency woofer and 25 watts of power to the high frequency ribbon. You will also find the pre-amp controls,
including VOLUME knob, used to adjust the overall level of the internal power amplifier, as well as the innova-
tive Ribbon Level control. This four-position switch allows the mix engineer to contour the high frequency
response of the monitor allowing you to adjust for room acoustics or listening preference. The Rubicon R8a
has been designed to provide flat, accurate monitoring, and at the same time, to provide an adjustable
response curve so that the sound of other popular near-field monitors can be easily emulated.
PositioningtheRubiconR8a
Near field monitoring has become the choice of many engineers in large and small studios because it mini-
mizes the effect of room acoustics. This is especially important in today’s project studios since the budget
for room acoustics is often close to nothing. By positioning the reference monitors in the near field (close to
the listeners), you can greatly reduce the effects of room acoustics. The most important considerations when
evaluating the effects of room acoustics are reflective surfaces that are around the monitoring area. These can
include flat tabletops, glass mirrors or framed pictures, large open walls and even the surface of your mixing
console. Mostly all reflecting sound will eventually reach the listening position, but since it is slightly delayed
from the direct source, the result is random cancellation of some frequencies, or comb filtering. If possible,
remove any and all reflective surfaces. You
may also want to hang some acoustic foam
on walls that are close to the monitors. When
positioning the monitors you’ll want to set
up what is commonly referred to as the “mix
triangle”. In this ideal configuration, the
space between the left and right monitor
is equal to the distance from the listener to
each monitor, forming an equilateral trian-
gle. (Figure 1.)
Prime Listening Spot
Equal Distance
Figure 1.