In Car Ent: Two Alpine SWR-1242D Type-R 12" subwoofer dual 4-ohm voice coils

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SWR-1242D Two 12" type R subs used a few times for shows, not properly broken in yet. excellent condition, im in north coast area.

these are excellent value and the best bang for your buck. Looking £150 each or £250 the pair. cost over £200 new.

• 12" subwoofer with dual 4-ohm voice coils
• Kevlar reinforced pulp cone with Santoprene™ rubber surround
• cast aluminum frame with perimeter venting
• frequency response: 25-500 Hz
• power handling: 200-500 watts RMS (250 watts per coil)
• peak power: 1,500 watts
• sensitivity: 85 dB
• top-mount depth: 7-5/8"
• sealed box volume: 0.57-1.0 cu. ft.
• ported box volume: 0.75-2.0 cu. ft.
  
  Features
  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.
  
  HAMRS: The woofer features a High Amplitude Multi Roll Surround (HAMRS), made of injection molded Santoprene, that allows for an incredible amount of linear excursion and greater SPL.
  
  Mirrored Progressive Nomex Spiders: This subwoofer has twin mirrored progressive Nomex spiders for added stability and mechanical durability. The custom progressive rolls gives 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. The woofer has integrated tinsel speaker leads that are woven into the spiders for the one-sided terminal layout.
  
  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.
  
  Magnetically Optimized Motor Structure: Through Alpine's advanced magnetic circuit design, this woofer offers better sound quality, and a higher sensitivity and power handling capability:
  
  • 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: The extra thick top plate keeps more windings in the magnetic gap for better control.
  • Dual Stacked Magnets: The dual stacked magnets provide the powerful magnetic energy and extra depth for high SPL and maximum control.
  • Bumped Back Plate: This "bottomless" design provides extra room for longer cone excursions.
  • Optimally Saturated Pole: The optimally saturated pole reduces magnetically induced heat by eliminating eddy currents throughout the voice coil stroke, and evens flux distribution to eliminate "hot spots."
  Multi-Stage Ventilation System: The SWR-1242D has a multi-stage ventilation system with the following features:
  
  • Cone/Voice Coil Junction Venting: The unique parabolic cone and voice coil attachment piece help to pull cool air into the motor structure.
  • Spider Plateau/Leg Vent System: Two vertical slits are cut into each of the five "legs" of the basket below the spider to allow cool air to flow in and heated air to flow out.
  • 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 4-ohm load.
  
  Power Handling: This woofer has a total RMS power rating of 500 watts and a total peak power rating of 1500 watts. Each voice coil carries an RMS power rating of 250 watts and a peak power rating of 750 watts.
  
  Push Terminals: The push terminals are all located on one side of the woofer. The terminals will accept bare wire, pin connectors, banana connectors, and dual banana connectors.
  
  Jumpers: The woofer is equipped with two voice coil connection jumpers. These jumpers allow you to wire the voice coils in parallel (for a 2-ohm load) or series (for an 8-ohm load).
  
  Enclosure Compatibility
  Recommended Sealed Box Volume: The sealed box sizes recommended by Alpine range from 0.57 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 2.0 cu/ft. Within this range, the ideal size recommended by Alpine is 1.7 cu/ft, so this is the enclosure recommended by Crutchfield. A slot port with the following dimensions should be used with the 1.7 cu/ft enclosure: W = 12", H = 1.25", L = 21". If you cannot use a slot port in your enclosure, you will need a port tube with the following dimensions: Diameter = 3", L = 9.9".