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Alpine SWX-1243D

Type-X 12" subwoofer with dual 4-ohm voice coils

18 Reviews

Item # 500SWX1243

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Our take on the Alpine SWX-1243D

Feed your Alpine Type-X subwoofer some serious power, and it'll unleash powerful bass to enhance your journey. And Alpine's advanced design, quality materials, and rigorous construction ensure that you'll get years of reliable use.

Alpine Authorized Online Dealer

Feed your Alpine Type-X subwoofer some serious power, and it'll unleash powerful bass to enhance your journey. And Alpine's advanced design, quality materials, and rigorous construction ensure that you'll get years of reliable use.

The SWX-1243D 12" subwoofer features a 3-layer cone — a layer of Kevlar®, a layer of plastic film, and a bottom layer of pulp reinforced with Kevlar. This design provides outstanding response and accuracy, while the cone's parabolic shape maintains rigidity and strength. The multi-roll Santoprene™ rubber surround maximizes the cone's performance with its ability to go deep. The concealed mounting gasket gives your sub installation a clean look.

On the inside, the SWX-1243D is all business. A massive, triple-stacked strontium magnet anchors the sub, while the single-piece cast aluminum frame and motor support holds provides the backbone you'll need for big bass. Increased venting and heat dissipation areas keep your sub running cool, so it'll survive conditions that would destroy lesser speakers. This bruiser can handle up to 1,000 watts RMS, so don't hesitate to give it some juice.

You can wire the dual 4-ohm voice coils to get the optimum performance from your amp, or to configure a custom setup with multiple subwoofers. Rock the bass the way you want to with the mighty Type-X subwoofer.

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

Priced per speaker

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

Product Highlights:

  • 12" subwoofer with dual 4-ohm voice coils
  • pulp/fiber cone reinforced with Kevlar and a layer of Rohacell® plastic film
  • Santoprene rubber surround
  • cast aluminum frame
  • power range: 500-1,000 watts RMS (500 watts per coil)
  • peak power handling: 3,000 watts
  • frequency response: 24-200 Hz
  • sensitivity: 84 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
  • warranty: 1 year
  • Our 60-day money-back guarantee

What's in the Box:

  • One 12" Dual-voice-coil subwoofer
  • 1 Rubber mounting ring (installed)
  • 1 Top-mount rubber concealing ring
  • 1 Bottom-mount rubber mounting ring
  • 2 Voice coil configuration jumpers
  • 2.5mm Hex wrench
  • Application Guide
  • Warranty sheet
  • Customer Care Registration card
  • Important Notice sheet

Great subs I hooked them up and they are loud and hit hard will be buying more for my girls car

Mike260, North Manchester in


Alpine SWX-1243D Reviews

Average Customer Review(s):

(18 Reviews)


Mike260 from North Manchester in on 1/19/2013

Crutchfield Customer Review (What's this?)

Great subs I hooked them up and they are loud and hit hard will be buying more for my girls car

Pros: Deep bass

Cons: One of the speakers didnt come with everything the other one did like instructions and hardware

Pounds with longevity :)

John from Texas on 11/13/2012

So first off this thing pounds. I mean pounds, hair standing, mirror falling off, cop car four blocks down shaking, pounds. Second, the quality of the build these cannot be over emphasized. My brother had this before me and then gave it to me and is now 7, almost eight years old, and still pounds after being beat every day, hard. For SQL that will last as long as the car it's in, this sub is unbeatable.

Pros: Long life Loud Looks good Amazing SQ

Cons: None

Amazing subwoofer

Brandon from Austin, TX on 5/22/2012

First of all, this subwoofer is hands down one of the best on the has a mix of SQ and SPL. I have mine in a 1ft cubic box that is custom built for this subwoofer and it is a powerhouse. I have it hooked up to a PDX M12 which runs it at 1200RMS and it handles all of the power with ease (I wouldn't give it any more power than that). It is one of the best subs and has never failed to impress me for the nine months I've had it. There is honestly nothing wrong with this subwoofer and is a guaranteed great buy.

Pros: SQ, SPL, Installation, etc.

Cons: Absolutely Nothing

Type X is dangerous

J from Martin TN on 11/25/2011

man these things are dangerous. i dont have them pushed to the 1000 watt rms and they still are punishing my car. worth every penny. quality of this sub is amazing. alpine did it right when they produced this sub. Thanks

Pros: Everything

Cons: $250 overpriced on crutchfield

clean hitting

Alpine Fan from challis idaho on 4/17/2011

Crutchfield Customer Review (What's this?)

I would definitely recommend this sub, for someone who likes clean precise bass that hits real low tones. I have one of these in my grand Cherokee, and am very happy with the sound quality of the x. I have two alpine type r's in my eclipse. The x seems to hit the low tones better than the r's however the x is not as loud. Thanks alpine.



Great Sub

jarvas36 from Phoenix AZ on 2/25/2011

Pushed this sub hard everyday for almost five years straight. Only got rid of it since my new vehicle would've had a hard time carrying the weight and electrical demand. I first used this sub in a slot vented enclosure originally designed for a Power series Rockford 12 and was able to hit a solid 142-145 decibels using an Infinity 1211a amp. I then put the sub in a vented enclosure that was built to Alpine's specs and enjoyed the best of both worlds. Both low and clean tight bass.



alpine typr x

Anonymous from raleigh nc on 8/2/2010

i love this sub. lots of bass.



Get a type R.

Kaptacular from Homer Glen, IL on 2/23/2010

I had 2 of these Alpine Type-X subwoofers powered by 2 Alpine M1000 amplifiers. They sounded good, very close to how the Type-R's sounded, just a bit lower hitting. My left sub blew after a year, and I never really beat on it. I've had type r's for 2.5 years before I upgraded to type x's. I regret doing so.



Alpine SWX-1243D

matt from lafayette LA on 8/4/2009

I bought a brand new Gmc Yukon Denali and i have 3 alpine type x 12's in a custom ported box. I had to go with Alpine because they never let u down so i hooked up 3 Alpine PDX-1.1000 amps to them with 3 10 farad caps Ive goin through 3 back windows since Ive had the truck only 4 months there is no better sub than a type x in my opinion and if u buy one u will not be disappointed.



Amazing subwoofer! Buy it

ConnorRepmo28 from Springfield,Missouri on 4/2/2009

i started my car audio journey with two jl audio 10's in a ported box and those things hit pretty well. But i sold those to a friend with the plan to build my dream stereo. i did my research and decided on one 12" alpine type x with a 2000 watt amplifier. i have a normal car battery and a 10 farad capacitor. Let me tell you that thing hammers so hard my rear view morror has fallen off. i have it 151.3 db with only one in a 4 cu.ft. box. i am only running 1100 watts continuous. i am in the market to buy another 2000 watt amp to add to the one i have. The great thing about this sub is that it can handle so much more then what it is rated for. The local car audio shop has pushed one with 4500 watts to it and it loved it. hit every single not with so much power. now i dont suggest doing that with yours im just saying that the 1000 watt continuous is not legit. neither is the 3000 watt max. so if you are looking for a true super sub then buy this one and dont waste all your money on a jl audio w7.



love it

rip21 from mo county,md on 3/4/2009

i love this sub i used to have 2 alpine type r's and two xplod amps and they served me well for a least 2 years if not longer. when they gave out it was time to upgrade. of course i had to go with alpine so i got this alpine type x. i'm running an Alpine - 1000W Class D Mono MOSFET Amplifier with Adjustable Crossover to it. and i have it in a BS112V box. i also have a cap. but any ways i would recomend to put this sub in this paticulaar box because i had it in just a regular sealed box while i was waiting for my box to come in and it sounded nice but it wasnt as loud as my old setup,but once i put it in that new box omfg it is so loud i love it.



Alpine's best SQ/ SQL subwoofer

ProjectPechkin from Denver, CO on 12/4/2008

This is an excellent driver, and like all other drivers, they work best in a custom built box. It's really a regret to see people run $500 drivers (subwoofers) with $20 boxes. I initially had this in a 1.1 cubic foot sealed enclosure, and it is very SQ. Taking 1000 RMS was no problem for this beast. In it's optimum enclosure, it will take 1.5kw on music in a sealed box. This is a SQ/SQL driver, and it is not meant to be compared to it's SPL brother, the type R. Please don't say Type X's bump harder then type R's. Type R's can get a heckuvalot louder, and handle more power, but this again has to do with your enclosure! Later when I re did my system, I put the Type X in a 2.1 cubic foot box tuned to 33Hz. Amazing output, and the sub was feed with 1200 RMS, which is about all I would feed this thing daily in a ported enclosure. It's an amazing driver, and I'd recomend this to people looking for an SQ/SQL setup. These are not louder then TYPE-R's. I preform custom mobile installations for a living. This is fact!




Archery tech from Daytona Beach, FL on 5/28/2008

i crammed 2 of the monsters in a ford F250 Superduty, by creating a custom center consol. i powered them with 2 alpine PDX 1000x1 amps. they are amazing. i've already nocked my rearview mirror off! insane! alpine is the only way to go, and if you want to go big, these are the subs for you!




badst0rm from Boca Raton FL on 2/10/2008

WOW just WOW.....I have this hooked up to a Alpine PDX-1.1000 mono amp,A alpine IDA-X001 Alpine headunit and it just sounds amazing.It is in a sealed fiberglass box at 1.15 cubic feet. right now at the amp less than half way up it hits well over 100 dbs. IF YOU WANT SOME EXTREME BASS GO WITH THIS HANDS DOWN.



Bar None

Junious84 from Atlanta, GA on 12/1/2007

I purchased two of these MONSTERS and honestly didn't know what I was getting myself into...when you read these other reviews and they emphasized on how powerful these things are...THEY DO NOT EXAGGERATE!!! I have two in a custom ported box hooked up to a Bxi2006D, the sound is crazy. I have had people actually leave my car in tears its so loud! I have won 3 comps and I'm coming for #4. This was the best investment I have made so far!!! I dared to turn it up all the way one day and warped the hinges on my trunk. Be warned...they are not for the weak hearted but for the true lovers of BASS!!!!!



Sav'n for TWO!

T-RAY from Foley, Al. on 11/8/2007

I REALLY dont see why this doesn't have a perfect rating! For monster bass, this sub DELIVERS! I have one in a custom ported box built to max specs with the all powerful Alpine PDX-1.1000 and for being one sub, this baby knocks, pounds, quakes, however you want to put it! <BR><BR> I'm really looking foward to getting another of each! With my one reaching 146 dB, I cant wait to hear what two sound like! Monster lows and SQ is not lost! This sub will pound whatever song you put on it! Even rock music,which is my majority listening, is insane! <BR><BR> Even if you've heard this sub performs better in a sealed box, which for loud SQ it sounds great, I have to recommend a ported! I tried them both and was much happier with the ported. Alpine to me is the only brand that I truly believe is best in EVERYTHING! Subs, amps, speakers, HU's, and ofcourse touch screen HU/DVD! Best brand ever!




Drew from Phila PA on 5/12/2007

These subs quake!! I two of them in a ported Q-logic box powered by two MTX TA5601 thunder series amps. i only have approximatly 700 watts going to the subs and the bass is insane! I would be afraid to put any more power to them! Excellent sub. and i love the &quot;blade&quot; that is used to wire the subs in series or in parallel.




juglo from milwaukee, wi on 5/3/2007

this is a great subwoofer, it pounds<BR>i have 1 type x in a custom ported box(none of that mdf bs)built to alpine's specs, a hk2000d class x comp. amp(1200w rms @2ohm) powering it and a 1fared cap.<BR>though you wont out spl any one with some decent subs in a ported box with only 1 of these, this sub still hits hard. <BR>It hits everynote perfect and for being a 1000w sub it has amazing response time great sq, which is normally lost after exceeding 500w rms for a sub. It hits lows wonderfully, the highs are decent but its a subwoofer its ment for lows and mids which sound beautiful on this woofer. <BR>i would recamend this woofer to anyone who has the money, 1 of these puts out as much bass, wait more bass than my 2 12" polk momos did and those were loud.<BR>from what i have herd from others this woofer is better in a sealed box but thats your call




Hands-on research

Product Research



Aerospace Cone Material: The Alpine Type-X woofer uses new advanced aerospace materials for the cone, known as Kevlar-Rohacell which provides outstanding strength at a lighter weight. These lighter materials minimize moving mass for greater output efficiency.

Santoprene Surround: The woofer features a High Amplitude Multi Roll Surround  made of injection molded Santoprene, that allows for an incredible amount of linear excursion and greater SPL.

HAMR Engineering: The Alpine Type-X sub is built with HAMR engineering, Alpine's exclusive subwoofer solution for cooler operation, longer life and tight accurate bass.

Dual 4-ohm Voice Coils: The Alpine Type-X woofer features dual 6-layer voice coils which utilize 220°C high-temperature wire with Inner/Outer Winding on a Twin-Wall 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 reinforced layer tinsel speaker leads that are woven into the spiders for the one-sided terminal layout.

Multi-Stage Ventilation System: The Alpine Type-X woofer 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.

Cast Aluminum Exo-Frame: The Type-X woofer utilizes a custom, one-piece, cast aluminum Exo-Frame with perimeter venting. 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 also features an integrated spider landing and heat transfer plate.

Rubber Concealing Ring: The woofer includes a rubber concealing ring to cover the screw holes when top mounting the woofer. The top-mounted concealing ring increases the woofer's top mounting measurement to 1.3125".


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 1.0 cu/ft.

Recommended Vented Box Volume: The vented box sizes recommended by Alpine range from 1.0 cu/ft to 2.0 cu/ft. with an ideal volume of 1.8 cu/ft. A slot vent, with the dimensions of 12" x 1" x 24", is recommended.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.