Kevlar Reinforced Pulp Cone:
This Alpine Type-R subwoofer has a Kevlar reinforced pulp cone. Kevlar adds
strength and tear resistance to the woofer cone while maintaining the benefits
of a pulp cone design. There is also an oversized inverted dust cap of the same
material, which increases rigidity and virtually eliminates distortion at
extreme volume levels.
Santoprene Rubber Surround: The
high-excursion 1" Santoprene rubber surround is durable and resistant to
the elements, resulting in a very reliable performance. The surround is
specially designed to resist deformation that is common in most woofers with
wide surrounds. This design gives the surround more control over the woofer cone
to reduce distortion and possible driver failure.
Dual Progressive Nomex Spiders: This
subwoofer has dual progressive Nomex spiders for added stability and mechanical
durability. The custom progressive rolls give the woofer a longer, more linear
stroke with maximum centering and restoring force. Special edge control design
and Nomex construction provide excellent tear resistance, strength and long-term
reliability. By integrating the tinsel leads into the top spider, a nearly
3" peak-to-peak excursion can be achieved with a shallow cone design.
Magnetically Optimized Motor
Structure: Through Alpine's advanced magnetic circuit design, this woofer
offers better sound quality, and a higher sensitivity and power handling
- Compound Radius Curve Pole
Geometry: This patent-pending design intensifies the magnetic field for
higher SPL and lower distortion. The magnetic field is balanced over a wider
area for better control at high excursion.
- Extra Length Extended Pole:
The extra long pole piece provides additional surface to capture radiated
heat for additional power handling.
- Extra Thick Top Plate: This
keeps more windings in the magnetic gap for better control.
- Double Stacked Magnets:
These provide the powerful magnetic energy and extra depth for high SPL and
- Bumped Back Plate: This
"bottomless" design provides extra room for longer cone
- Optimally Saturated Pole: This
reduces magnetically induced heat by eliminating eddy currents throughout
the voice coil stroke, and evens flux distribution to eliminate "hot
Cast Aluminum Frame: The woofer
is mounted to a custom cast aluminum frame for added strength. This high mass
frame also dissipates heat quickly to make it an integral part of the woofer's
thermal management system.
Heat Transfer Plate: This
subwoofer contains an integrated heat transfer plate that is thermally coupled
to the voice coil. This plate pulls heat away from the voice coil and transfers
it to the cast aluminum frame, achieving up to 20% additional power handling,
and better reliability.
Dual Flare Pole Vent: Another
part of the thermal management system is the unique dual flare design of the
pole vent. This maximizes the flow of cooler air to the voice coil, and results
in better power handling.
Dual Voice Coils: For increased
system flexibility, the woofer has two 4-ohm voice coils. When the voice coils
are wired in parallel with each other, the woofer presents a 2-ohm mono load.
When the voice coils are wired in series with each other, the woofer presents an
8-ohm mono load. In addition, each coil may be connected to a different
amplifier channel and each channel will see a 2-ohm load.
The woofer has two pairs of spring posts which will accept pin connectors and up
to 8 gauge bare wire.
Power Handling: This woofer has
a total RMS power rating of 300 watts and a total peak power rating of 1000
watts. Each voice coil carries an RMS power rating of 150 watts and a peak power
rating of 500 watts.
Recommended Sealed Box Volume:
The sealed box sizes recommended by Alpine range from 0.7 cu/ft to 1.0 cu/ft.
Within this range, the ideal size recommended by Alpine is 0.85 cu/ft, so this
is the enclosure recommended by Crutchfield.
Recommended Vented Box Volume:
The vented box sizes recommended by Alpine range from 0.75 cu/ft to 1.75 cu/ft.
Within this range, the ideal size recommended by Alpine is 1.25 cu/ft, so this
is the enclosure recommended by Crutchfield. One 4" diameter x 13"
long port should be used with the 1.25 cu/ft enclosure.
Frequency Response: The manual
lists the frequency response as "Fs-1kHz" (Fs=Free Air Resonance
frequency). According to Alpine, the actual frequency response is 24Hz-1kHz.
Recommended Enclosures: The
manual only lists the recommended sealed box volume range. The vented box volume
recommendations were obtained directly from Alpine.