Community iBOX Installation/Operation Manual — Page 13
High voice coil temperatures have undesirable effects on performance. Thermal expansion can result in
warpage and misalignment of components. A voice coil whose diameter has increased due to thermal
expansion will often no longer be round, and has a greater possibility of rubbing against the magnetic structure.
Any amount of cooling that can be applied to a woofer will be beneficial. One very commonly used
cooling method is venting of the pole piece of the magnet structure. The motion of the cone assembly will pump
air in and out of the cavity under the dust cap. This air passing through the pole vent helps to cool the magnet
structure. Community has improved on this common cooling method by introducing an airflow director (US
patent 6,390,231) into the air path. Figure 2 shows a conventional woofer with a vented pole piece (left), and a
Community Cool-Coil woofer. The voice coil former in the Cool-Coil motor is aluminum, and is taller than
normal. This extended aluminum former becomes a cooling fin for the voice coil, and the airflow director causes
the air to pass in close proximity to the former. By directing the air to flow over the hot aluminum former, more
heat is removed from the voice coil than simply allowing the pumped air to take its natural path in and out of the
cavity. This results in woofers that can handle higher power with greater reliability than conventional woofers.
Figure 2: Conventional (left) vs. Community’s Cool-Coil Woofer
I B O X M O D E L S
The iBOX Series of loudspeakers are designed for top-of-the-line installation work. Their premium
components are housed in rugged, acoustically inert trapezoidal enclosures. iBOX systems are characterized
by high-power and low distortion, with exceptional musicality and speech intelligibility.
iBOX models come in three basic form factors, or sizes. Within each form factor there’s one full-range
enclosure and two subwoofer models that are dimensioned identically to the full-range enclosure; this makes
clusters and arrays easy to assemble and exceptionally attractive when installed. A high-power rectangular
subwoofer (intended for use on the floor), a multi-layer glass composite stage monitor, and a small but highly
versatile system that can be used as an under-balcony speaker or stage monitor system round out the iBOX
line. All models are available in black and white. Most are also available in unfinished versions.
Each full-range enclosure can be ordered with a variety of horn coverage patterns. Most horns can be
field-rotated 90 degrees, allowing the enclosure to be used in either a vertical or horizontal orientation (see
following tables). iBOX loudspeakers array very well when used in multiples; the wide range of available
coverage patterns support tight-pack and splayed arrays, as well as exploded cluster and distributed system
designs. A variety of mounting yokes, arraying kits, and other installation hardware is available from the factory
as standard items.
All full-range iBOX models may be single-amped using the internal passive crossover, or bi-amped
using an external crossover. In either the single-amped or the bi-amped mode, the mid-to-high crossover in
three-way iBOX models is always passive. Here are brief descriptions of the available models.
MODELS