LOW’s

The three-way LSiM703 employs
a rear port and Polk’s Dynamic
Sonic Engine design, which
places the 3.25-inch midrange
driver and 1-inch ring radiator
tweeter in separate chambers
within the speaker enclosure, further
isolating the driver units from
the acoustic vibrations produced
by the woofer. The midrange and
woofer cones are constructed of
polypropylene, which is injected
with air to form a honeycomb
structure that combines the benefit
of low mass, stiffness and high
damping. The crossovers include
both Mylar and polypropylene capacitors,
as well as non-magnetic
air-core inductors, which are less
prone to electrical-signal distur-
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REVIEW
TONE AUDIO NO.54
bance and thus deliver improved
transparency. This construction
provides a good balance between
sensitivity and smooth frequency
response, and is indicative of the
speaker’s build quality in general—
from the flush grilles, right down to
the high-quality jumpers between
the binding posts, which can be
bi-wired.
Our review samples are finished
in an attractive cherrywood
veneer. (Ebony is also an option.)
The speaker’s MDF-based enclosure
is exceptionally inert, which a
classic knuckle-rap test confirms.
I leave the grilles off for all listening
sessions, though they will
come in handy wherever prying
fingers or noses lurk. I find that the
LSiM703’s bass response and imaging
focus benefit from inert stands,
and my 26-inch-tall Sound Anchors
prove a perfect fit.
Engineering Excellence
The detail paid to the time alignment,
transparency and coherency
comes through the LSiM703s immediately,
allowing the heart and soul
of the music to shine, regardless of
musical genre. Malian vocal legend
Salif Keita’s album Papa, with its
modal melodies and deep grooves,
is a magical experience through the
compact Polks, which require proper
toe-in to create a convincingly holographic
presentation. I suggest the
classic equilateral triangle configuration
for optimal results. (continued)
GIBRALTAR 1999-2013 RIP
ALL HAIL CASTLE ROCK!
Late one snowy night at a Michigan motel, January 1999, I designed Gibraltar speaker cable for my own system.
I needed an extremely high-performance cable which would provide true Double-BiWire performance in a single
attractive cable. While I needed to optimize a 2-way speaker, in which the transition between woofer and tweeter
is above the midrange, the challenge I enjoyed overcoming in those early morning hours was designing a cable
which would also be equally e ective Full-Range or when used to BiWire a 3-way speaker (in which the bass/treble
transition is below the midrange, the midrange information being carried by the treble cable rather than by the bass
cable as with a 2-way).
Original Gibraltar’s all important basics – superior geometry, almost ideal isolation between the magnetic elds of the
bass and treble signals, Perfect-Surface metal, conductor size maximization (AQ’s SST), etc. – are the fundamentals
of our new Castle Rock cable, as are crucial post-1999 improvements to Gibraltar, such as even better metal and AQ’s
DBS (Dielectric-Bias System).
You might not notice that Castle Rock’s new more nicely sculpted “breakout” (covering where the cable separates
into red and black legs) is no longer metal. We have made this all-models upgrade because speaker cables and AC
cables carry large magnetic elds which interact with any metal “collar” around the cable.
Smaller ingredients, such as non-metallic breakouts and the new NDS (Noise-Dissipation System) built into Castle Rock,
and bigger changes, such as Castle Rock using the same sleek new Signature Series spades and bananas developed for
the WEL Sig. Series cables, add up to an important di erence in what you hear and enjoy.
Even though the jump up from last-generation Gibraltar to Castle Rock is no bigger than the cumulative
improvements brought to Gibraltar over its long life, Castle Rock’s own new systems and materials earns it a new
name to honor Gibraltar’s long-term evolution + Castle Rock’s new ingredients.
Happy listening!
William E. Low
April 2013 169