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Type-R 8" subwoofer with dual 4-ohm voice coils
Our take on the Alpine SWR-843D by Crutchfield's Jo Greene
Bass production is all about moving air and Alpine's Type-R subs do that better than ever. Advanced suspension features give these powerhouses the extra-long cone excursion needed to push large amounts of air, while the Kevlar® treated pulp woofer cone and big Santoprene™ rubber surround promote accurate response. Best of all, these subs feature shallower mounting depths than previous Type-R subs, so you can fit them into more spaces in your vehicle.
Impressive power handling
The SWR-843D 8" subwoofer handles up to 350 watts RMS for big-time output, and its dual 4-ohm voice coils offer system wiring flexibility. It works well in sealed or ported enclosures so you can choose what kind of bass you want to hear and feel. The one-piece aluminum frame houses a heavy-duty magnet structure for increased accuracy and power handling, along with a special-design heatsink that shunts off excess heat for long-lasting reliability.
Note: If you are wiring this DVC sub for lower impedance, make sure that your amp is compatible.
Priced per speaker
Note: Sorry, Crutchfield cannot ship Alpine products to Guam or Puerto Rico.
- 8" subwoofer with dual 4-ohm voice coils
- Kevlar reinforced pulp cone with Santoprene rubber surround
- cast aluminum frame with perimeter venting and radial finned heat sink
- frequency response: 28-200 Hz
- power handling: 150-350 watts RMS (175 watts per coil)
- peak power: 900 watts
- sensitivity: 83.5 dB
- top-mount depth: 4-1/2"
- sealed box volume: 0.3 cu. ft.
- ported box volume: 0.7 cu. ft.
- warranty: 1 year
- Our 60-day money-back guarantee
What's in the Box:
- One 8" Dual 4-ohm voice coil subwoofer
- 1 Rubber concealing ring (installed)
- Two 4.5" jumper cables (each cable has a banana connector on each end)
- Type-R Subwoofer application guide (English/ French)
- Customer Care Registration card
- Warranty information (English/ French)
- Important Notice (English /French)
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Features and Specs
|Impedance||2 ohms or 8 ohms|
|Cone Material||Kevlar Reinforced Pulp|
|Surround Material||Santoprene Rubber|
|Ideal Sealed Box Volume (cubic feet)||0.3|
|Ideal Ported Box Volume (cubic feet)||0.7|
|Port diameter (inches)||N/A|
|Port length (inches)||N/A|
|Dual Voice Coil||Yes|
83.5 dB at 1 watt |
|Frequency Response||28 - 200 Hz|
|RMS Power Range (Watts)||150-350|
|Peak Power Handling (Watts)||1000|
|Top Mount Depth (inches)||4 1/2|
|Bottom Mount Depth (inches)||5 3/16|
|Cutout Diameter or Length (inches)||6 15/16|
|Parts Warranty||1 Year|
|Labor Warranty||1 Year|
Kevlar Reinforced Pulp Cone: This Alpine Type-R subwoofer has a two-piece structural parabolic 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.
HAMR: The woofer features a High Amplitude Multi Roll Surround (HAMR), made of injection molded Santoprene, that allows substantial linear excursion and greater SPL. The High-Amplitude Multi Roll Surround design allows extreme excursion without sacrificing valuable cone area. FEA Optimized for linearity and made with injection-molded Santoprene, the HAMR surround is a key part of the suspension system that allows extreme excursions with accurate, distortion-free control.
Spider with Reinforced Layer Spider Integration: An FEA optimized progressive Nomex spider with reinforced layer spider integration ensures reliable and consistent control of the tinsel-leads to eliminate any possible mechanical noises or interference typical of many high-excursion designs.
Vented VC Heat Sink and Airflow Management System: Alpine's Patented Radial Vented VC Heat Sink and Airflow Management System actively manages voice coil temperatures by forcing air directly across the heat sink system. This helps to minimize power compression and ensures reliable long playing time by actively removing output-robbing heat from the voice coil. The new one-piece cast aluminum frame with integrated shorting sleeve uses the entire frame as a heat sink, allowing sustained power output and handling, even in the most extreme applications.
Optimized Motor Structure: Thanks to its new six-piece, segmented, double stacked magnet structure, the new Type-R subwoofers have over 20% more motor force than their predecessors, offering more control over cone movement. The optimized machined motor structure also creates a symmetrical magnetic field while optimizing flux density to greatly reduce distortion, while further improving power handling and output.
Pole Geometry: Alpine's patented Compound Radius Curve pole geometry ensures a symmetrical magnetic field, while optimizing flux density to reduce distortion, while further improving power handling and output.
Oversized Voice Coil: The 40mm high-temperature (180°C), 4-layer dual voice coil offers more surface area to handle more power; 350W RMS / 1000W Peak.
Dual Voice Coils: For increased system flexibility, the woofer has two 4-ohm voice coils. When the voice coils are wired in parallel the woofer presents a 2-ohm load; when the voice coils are wired in series the woofer presents an 8-ohm load.
Spring Terminals: The spring terminals are all located on one side of the woofer. The terminals will accept pin connectors, single banana plugs, or bare wire up to 8 gauge.
Jumpers: Included with the woofer are two voice coil terminal jumpers. These jumpers allow you to easily wire the voice coils in parallel (for a 2-ohm load) or series (for an 8-ohm load).
Enclosure Compatibility: The 8" Alpine Type-R Subs offer installation flexibility; they are compatible with sealed, vented, or bandpass enclosures, and infinite baffle installations (no bandpass enclosure specifications are listed in the manual).
Sealed Box Volume: Alpine recommends a sealed enclosure with an optimum internal volume of 0.3 cubic feet (from 0.15 to 0.5 cubic feet is acceptable). Sealed enclosures provide the most control over a woofer, will handle a lot of power, and provide accurate sonic reproduction, making them suitable to all types of music.
Vented Box Volume: Alpine recommends a vented enclosure with an optimum internal volume of 0.7 cubic feet (from 0.25 to 0.7 cubic feet is acceptable) using a 7"x3/4"x15-1/2" slot port; this yields a tuning frequency of 36 Hz. Ported (or vented) enclosures typically provide better overall efficiency than sealed so they are suitable for use with smaller amplifiers, giving you more bass output from less power. However, this efficiency comes at the expense of very low frequency output (below 31 Hz).
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