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Alpine Type-X SWX-1242D

12" subwoofer with dual 4-ohm voice coils

14 Reviews

Item # 500SWX1242

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Our take on the Alpine Type-X SWX-1242D

Bass alert — Alpine's Type-X subwoofers bring the ultimate combination of power and performance to your sound system. Engineered with high output in mind, Alpine's top-of-the-line subs handle a mind-blowing 3,000 watts of peak power, while still reproducing the tight, low frequency detail that means great bass.

Alpine Authorized Online Dealer

Bass alert — Alpine's Type-X subwoofers bring the ultimate combination of power and performance to your sound system. Engineered with high output in mind, Alpine's top-of-the-line subs handle a mind-blowing 3,000 watts of peak power, while still reproducing the tight, low frequency detail that means great bass.

The SWX-1242D 12" subwoofer provides full bass by squeezing every last millimeter of excursion from the carbon fiber/aluminum honeycomb cone, thanks to its high-roll Santoprene rubber surround. A patent-pending basket design uses air channels in the frame to force out hot air and miminize distortion. It all adds up to huge output and terrific sound quality.

The reinforced tinsel lead design places both terminals on the same side, providing easier installation and wiring. The unique terminals easily accept high-gauge speaker wire. The SWX-1242D is designed for use in sealed or vented enclosures.

Note: If you are wiring this DVC sub for lower impedance, make sure that your amp is compatible. Most car amplifiers are stable down to 2 ohms in standard mode, or 4 ohms in bridged operation.

  • 12" subwoofer with dual 4-ohm voice coils
  • carbon fiber/aluminum honeycomb cone with high-roll Santoprene rubber surround
  • cast aluminum frame
  • frequency response: 23-200 Hz
  • power range: 500-1,000 watts RMS (500 watts per coil)
  • peak power handling: 3,000 watts
  • sensitivity: 83 dB
  • top-mount depth: 8-11/16"
  • sealed box volume: 0.65-1.25 cubic feet
  • ported box volume: 1.0-2.0 cubic feet
  • Recommended Q-Logic Box Type: 1, 2, 3
  • warranty: 1 year

Priced per speaker

Note: Sorry, Crutchfield cannot ship Alpine products to Guam or Puerto Rico.

This sub is insanely loud. I had in Chevy Malibu and then moved it to a smaller hatchback and set it up so it fired at the rear window. It got so much louder The amp is only putting 800 watts into it and it still sets of car alarms.

jake, Milwaukee, WI

What's in the Box:

  • 12" Dual-voice-coil subwoofer
  • Reverse mounting gasket
  • 2 Voice coil configuration jumpers
  • 2.5mm Hex wrench
  • Application Guide
  • Important Notice
  • Warranty sheet
  • Customer Care registration card

Alpine Type-X SWX-1242D Reviews

Average Customer Review(s):

(14 Reviews)

Sick sub!

Mr.Alpine from LA, CA on 1/15/2013

Ive got a bout a month on this sub. I have it in a 1.2^3 box so Net is about 1^3 sealed. My baby is being powered by an 2200D amp. Its definitely seeing a solid 900-1000W Rms. I'm still in the break in stage of course but It hits like no other sub Ive heard. My girls 2004 Celica has two 12's in a big slotted box with a 2400W amp and yes hears has some serious low end SPL, but cant even come close to the SQ and hard hitting and god all mighty loudness of mine. I can only imagine how loud the ported box would sound. Eery person that takes a listen is very pleased with it.

Pros: Solid sub. Worth every penny!!

Cons: If I come up with any Ill be sure to let you know!

Hits clean and hard!

Josh from Arizona on 12/7/2006

I have one of these in my 01 4Runner powered by an MRD-M1005 and holy god it bumps. I have it in a ported 1.8 cubic foot box and it pounds INSANE. I usually have to have it turned down to about 20% or I get a headache. When I crank it up, I can wake up a whole neighborhood. It hits pretty clean, but I think it would hit a little cleaner in a sealed box (although it won't hit as loud) I would recommend this to anyone who wants a quality sub with good SW and excellent SPL. Don't underpower this sub, buy a good amp!



Alpine Type-X SWX-1242D

jake from Milwaukee, WI on 10/3/2006

This sub is insanely loud. I had in Chevy Malibu and then moved it to a smaller hatchback and set it up so it fired at the rear window. It got so much louder The amp is only putting 800 watts into it and it still sets of car alarms.




xerox from Great Falls, MT on 7/2/2006

I HAD 2 of these in my car for quite some time with an MRD-M1005 amp to push each one. HOLY COW!! Insane. They were loud in my 94 T-Bird but once I loaded them into my 91 Eclipse, it was even louder. These subs are insane. Unfortunatly some losers decided to jack my entire system while I was at the movie theatre watching Tokyo Drift. I love Alpine to death, but I'm afraid my curiousity might direct me towards the Rockford Power Stage 2.



lots of power!

tony from houston tx on 6/20/2006

these subs are very powerful! but u definitely need a strong amp for them. i have two of these in my trunk and im feeding them a lil bit over 2,200 watts(pdx amps). they want more power! they eat my amps for breakfast, seriosly they could probably handle 2,000 watts apiece without distorting.




fr3ddi3mr from Teoc, MS on 5/2/2006

I have a custom built ported, downfiring box with 2 of these subs in it powered by 2 Rocksford Power T10001bd with 2 one farad RF digital capson each. My old system was 1 RF Punch 10 and an M500 Alpine amp and so the upgrade is spectacular! My head unit is the Alpine IVA-D310 and I can tell a huge difference in bass at lower volumes - almost too much. I have made some changes in my eq setting to lower the bass and bring the highs up. I read other reviews of this woofer and went with a powerful amp as well as a full coating of dynamat in my Jeep Grand Cherokee. I no longer have to ride around with the volume maxed out when I go on the highway with all windows open. My reason for this woofer was price, over-all power handling (3000 watts peak) and sound. I heard a pair of these and was blown away by the bass. I have not yet opened the volume up all the way on these but at 25 - 28, the bass shakes the screen of the TV and the dash-top GPS (Blackbird by Alpine) - not to mention the rear-view and side-view mirrors and windshield wipers. I had a hitch on to haul my four-wheeler around and the bass was shaking it so much that I took it off. I wish I didn't have the spare tire in the trunk too. I guess that is a negative with a downfiring box. I have a rear seat TV\DVD consol mounted behind the sun roof and the DVD player will freeze if playing when volume is up. Luckily, I have it connected to the IVA-D310 so I only use it for back seat viewing of the front tv. I have opened a coke and set it in the cup holder up front and it has shaked so much that it was foaming. So far I have only set off 1 alarm with this system but it is new and I have not been on the prowl.




Clintface from housto tx on 2/27/2006

oh man i love these subs. i was driving through a construction site and my subs was hittin so loud it popped my tires. these subs hit so hard my grandma was sittin in the back seat of my car n it through her pace maker right out of her chest. Recommended for n e one who hates there grannie.




Cedric from Charlottesville, VA on 10/26/2005

These subs are simply the best. I have 2 in a ported enclosure running off of 2 Alpine MRD-M1005 with 1000 watts to each. They Hit so's hard to breathe. I have them in my grand cherokee with full trunk dynamat but I recommend a full body dynamat if you get these. Amazing subs.



loud and great sound quality

dave from rochester, ny on 8/30/2005

loud loud loud loud. great sound quality even in an ported box




Christopher from Albuquerque on 7/3/2005

I built a custom sealed enclosure at 1.35 cubic foot per side, for a pair of these and ran them sharing 1000W RMS. It became obvious that they want more power than 500 each, so I'm buying a new amp that will probably result in my having to upgrade my vehicle's alternator. But what I did notice is that they are extremely "musical" and accurate, plus tight and very forward with their impact. They can play the sweetest of music beautifully and also push some crazy sound pressure. I was literally laughing out loud with pleasure when I first finished a couple hours of loostening them up. They're expensive, but "Wow!" they sound good. Top quality SQ, plus intense power... what more could you ask for? Oh, and don't pay attention to the 23 Hz low frequency response; these puppies play 20 Hz LOUD and clear in the right enclosure/positioning.




sean from Michigan on 6/28/2005

this sub is amazing, i hit 148.9 DB's in a pontiac sunfire running it with alpines MRD-1000, definately worth every penny.



Hard hitting bass

Jon from auburn, NY on 3/22/2005

I have 2 connected to jl audio 500/1's. they hit so hard that i have to tighten my lugnuts about once a month. best subs i have ever heard



Alpine Type X

Matt from St. Louis, MI on 3/2/2005

Wow! This sub is very nice it hits lows that rattle your brain and is insanely loud.




NOAH from VICTORVILLE, CA on 2/8/2005

OFF THE HOOK PAIN: That is exactly what you get, or I should say that is what your vehicle gets! Even with dynamat throughout my truck! the combination of these subs and audiobahn's A2300HCT amp has rattled my truck apart. Just imagine what they can do in a larger vehicle with more airspace to explode in. This is considering, my gain is at it's lowest possible level for it to make any noise at all, amp bass boost is off, and my bass on the deck is at (-7). yes that is negative. I had to wire an independent switch between the deck and amp, just so I turn it completely off to have some mellow time. If you are looking for a little thump, then don"t buy these bad boys!




Hands-on research

Product Research



Cone Materials: This Alpine Type-X subwoofer has a carbon fiber, aluminum honeycomb parabolic cone with a Kevlar-reinforced pulp underside.

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.

Screw Cover Gaskets: The woofer includes two rubber gaskets to cover the screw holes, one for top mounting and the other for bottom mounting.

Dual 4-ohm Voice Coils: The SWX-1242D features dual 4-layer voice coils which utilize 220°C high-temperature wire with Inner/Outer Winding on a Twin-Wall brass/aluminum former. Dual voice coil woofers offer flexibility in wiring. 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.

Terminal Block: The speaker terminals are all located on one side in a machined gold-plated terminal block with 2.5mm Allen-head set screws (an Allen wrench is included). There are slots provided for the supplied voice coil jumpers.

Jumpers: The woofer is equipped with two gold-plated 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).

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 (over 23mm one way) 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 dual braided silver tinsel speaker leads that are woven into the spiders for the one-sided terminal layout.

Cast Aluminum Frame: The Type-X woofers utilize a custom, one-piece, cast aluminum frame. The unique design provides the ultimate in voice coil cooling, creating a one-way airflow, keeping hot air from coming into contact with the voice coil. The frame features an integrated spider landing and heat transfer plate.

Multi-Stage Ventilation System: The SWX-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 four "legs" of the basket below the spider to allow cool air to flow in and heated air to flow out.
  • Dual Flare Pole: Optimizes airflow into the motor structure across the billet copper shorting sleeves and thermal coupling heat dissipation plate to increase cooling.

Magnet: The woofer is equipped with triple-stacked strontium magnets with an overall magnet weight of 130 ounces.


Recommended Sealed Box Volume: The sealed box sizes recommended by Alpine range from 0.65 cu/ft to 1.25 cu/ft. with an ideal volume of 0.9 cu/ft.

Recommended Vented Box Volume: The vented box sizes recommended by Alpine range from 1.0 cu/ft to 2.00 cu/ft. with an ideal volume of 1.8 cu/ft. A slot vent, with the dimensions of 13" x 1.5" x 27", is recommended.

Our Product Research Team

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