Alpine Authorized Online Dealer

Alpine combines outstanding materials with superior construction to create their Type-S Series speakers. Upgrade your factory speakers with these Alpines, and they'll fill your vehicle with high-fidelity sound at a reasonable cost.

The SPS-400 4" speakers use strong, lightweight polypropylene-mica woofers to handle the lower frequencies. Air-injected rubber surrounds keep cone movement under tight control, eliminating distortion and enhancing bass. Stamped steel frames provide rugged support for these speakers, and their low profile allows them to fit in more factory locations.

The 3/4" silk dome tweeters play your high notes smoothly and comfortably with no hint of harshness. These efficient Type-S speakers will sound great with a low-powered factory radio, but they're also made to handle the high power output of an external amplifier. Grilles are not included — factory grilles are appropriate for most installations.

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

Product Highlights:

  • 4" 2-way speakers (pair)
  • polypropylene-mica woofer cone with air-injected rubber surround
  • 3/4" silk dome tweeter
  • power range: 2-45 watts RMS (140 watts peak power)
  • frequency response: 97-22,000 Hz
  • sensitivity: 86 dB
  • top-mount depth: 1-13/16 "
  • warranty: 1 year
  • Our 60-day money-back guarantee

Hands-on research

What's in the box?

Download owner's manual

  • Two 2-way 4" speakers
  • Two 4x6" speaker adapter brackets
  • Two 12" lengths of speaker wire (each length of speaker wire has quick-slides on one end and bare wire on the other end)
  • 8 Self-tapping screws
  • 8 Speed clips
  • 8 Machine screws
  • 2 Strips of self-adhesive foam
  • Warranty sheet
  • "Important Notice!" sheet

Product Research


Poly-Mica Cone: Each speaker features a Poly-Mica cone. Mica adds strength and heat resistance to polypropylene, resulting in reduced distortion and improved reliability.

Air-injected Rubber Surrounds: For a smoother response and improved durability, the woofers use air-injected rubber surrounds.

Silk Dome Tweeters: Each speaker has a 3/4" Wide-Range Silk Dome Tweeter for smooth high frequencies.

Highly Efficient Design: The SPS-400's high-efficiency design allows the speaker to be run off of your factory or aftermarket head unit, resulting in an easy system improvement for many vehicles requiring a 4" or 4x6" speaker.

Shallow-Design: The Alpine SPS-400 features a stamped steel shallow frame. This shallow mounting design allows for easier installation in a wide range of door panels giving you a perfect fit.

4x6" Compatibility: The speaker comes supplied with a 4x6" speaker adapter bracket which allows you to mounting the SPS-400 in factory 4x6" locations.

No Grilles: No grilles are included with this speaker.

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 open the box, verify contents, 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.

Alpine SPS-400 Reviews

Average Customer Review:

10 reviews
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Fine Upgrade

Written By GW, New York on Tuesday, February 01, 2011

Crutchfield Customer Review (What's this?)

I installed the SPS 400 series as a factory replacement front speaker system for a
vintage Mercedes Benz . What a difference they make ! The highs are crisp and clean
and their bass handling capacity is more than sufficient for a 4" speaker.
Installation was pretty simple. Original speaker grills are used as no replacement grills
are supplied and fitment is not affected. I've yet to be less than satisfied with Alpine
audio equipment I've purchased and Crutchfield helps make the experience even more
satisfying with professional assistance.

Tweeters DO NOT swivel

Written By Silky D., Columbus, OH on Friday, January 21, 2011

I just want to point out that the tweeters do not swivel on this model as described. It even says they do on the Alpine website. I called their tech support and they confirmed... No swiveling on the SPS-400!

[Editor's Note: Thanks for bringing this to our attention. You are correct and we have corrected our database.]

Great Speaker

Written By brooklou, Hollywood, Fl on Monday, December 20, 2010

Crutchfield Customer Review (What's this?)

I installed these in the rear doors of my 2004 Silverado. Sound great and installation
was easy. Just had to drill a few holes for the mounting plates that were provided. When
I ordered these the sales tech recommended bass blockers and I am glad he did. I am
running a Sony head unit without an amplifier and there is more than enough power.
Along with the Alpine SPS600's I installed in the front doors the improvement in sound
and quality is very noticeable.

great speaker

Written By TOYZ4221, San Antonio on Thursday, December 16, 2010

Crutchfield Customer Review (What's this?)

Owning a Jeep Wrangler, the factory sound is terrible. I have been upgrading the
system with an Alpine stereo and just added these front speakers. It was nice to add
something other than the factory 4x6 speaker. The installation was a breeze and the
sound is nice and clean. I plan on adding the type r 5.25 in the overhead and the type r
6x9 s soon and installing an amp to power them. Cant wait to get the rest of them in.
Driving with the top down and trying to listen to the factory stuff at 65mph really sucks.
The price here at crutchfield is great and will be getting my next purchases through

Not so great

Written By Michael, San Marcos on Wednesday, May 20, 2009

Crutchfield Customer Review (What's this?)

I replaced one of the dash speakers in my Boxster with this unit. For comparison, I left the other stock speaker in and ran the stereo. I was surprised to find that the stock speaker was much better--from a clarity and brightness standpoint.

Alpine SPS-400

Written By Brent, Lodi, Ca. on Sunday, May 10, 2009

Crutchfield Customer Review (What's this?)

Bought these speakers to replace the ones in the rear door of my 05 GMC Sierra with the Bose system, and to compliment the new Alpines in the front doors. These speakers are small compared to the ones in the front door, but then again it is a small space in the rear doors. These speakers sound really good for their size. Better than the Bose speakers they replaced, not by an enormous amount, but definetly worth the price. The only bad thing is pulling off the inside rear extended cab doors to get to the speakers. No regrets buying these speakers, and would buy again. Have all Alpine speakers in my truck, and couldn't be happier.

Crisp as Kentucky Fried...

Written By hermano de musica, Vacaville, CA on Tuesday, November 11, 2008

I listen to a lot of different music, from swing to rock to rap. I was very skeptical about purchasing theses as I know that components are so much more efficient than coaxials. I decided to put them in my doors anyhow and I was surprised at the difference it made. The highs sound as crispy as fried chicken and make my old speakers look like cell phone speakers. The highs and mids are flat and will not wear out your ears if you listen for long periods at a time.

There is no doubt in my mind that components are superior but these handle my highs just fine for the front as I have Type-S components in the rear.

WOW! What sound for so small....

Written By Jeffrey, Glen Allen, VA on Sunday, October 26, 2008

Crutchfield Customer Review (What's this?)

I added these to the rear of my Nissan Quest Van and for such a small
speaker they really put out wonderful highs and mids to go along with a 6"
sub. With the compliment of 6x8 Pioneer 4ways in the front, the Quest is
really a pleasure to drive now. These are really powerful speakers to be so
small. Thanks to Crutchfield for all your help on answering my questions.
There is no reason to buy from anyone else. Crutchfield you're the

Alpine SPS-400

Written By Joseph, Chicago, IL on Thursday, August 28, 2008

Crutchfield Customer Review (What's this?)

I installed these in the dash of my 1988 Crown Victoria LTD. They sound great! Nice smooth extended top end, and decent low end for the size. It is rare to find a car speaker that can reproduce orchestral music without being harsh or grainy. They can also play hard driving rock with ease as well. These are really exceptional speakers, and provide a huge improvement over stock speakers. I would also recommend replacing your receiver to get the full benefit. I installed a Pioneer receiver, and it mates very well with these Alpines. I also installed Pioneer 6x9's in the back. The top end of the Pioneer speakers is pretty lousy (harsh and grainy) but the low end is superb, and that's all I am looking for from the rear speakers anyway.

I highly recommend these speakers! At this price with everything you need to install them, it's a no brainer!

Alpine SPS-400

Written By bryan, Kissimmee, FL on Wednesday, August 20, 2008

Crutchfield Customer Review (What's this?)

waz a good purchase. works well!!!!!

Get everything you’ll need to enjoy your new Alpine SPS-400

Reduce ambient road noise and your vehicle's "rattles," for better sound inside your car.
You may need speaker wire to connect your speakers to your amp or receiver.
Keep your speakers clean and dry. They compress to fit behind your speakers.
The right tools will help keep your installation simple and clean.
If your stereo doesn't cut the deep bass from your full-range speakers, a set of bass blockers can help prevent distortion and give you cleaner bass too.
Dynamat 10415 Xtreme Speaker Kit

Dynamat 10415 Xtreme Speaker Kit

Two 10-in. x 10-in. Sheets

Item #: 15410415


Add to Cart
Dynamat 10435 Xtreme Door Kit

Dynamat 10435 Xtreme Door Kit

With four 12" x 36" sheets — covers two doors

Item #: 15410435


Add to Cart
Dynamat SuperLite Tri-Pak

Dynamat SuperLite Tri-Pak

Triple package — 3 sheets, 12 square feet (Model #10612)

Item #: 15410612


Add to Cart
T-Spec 16-gauge Speaker Wire

T-Spec 16-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW16WB1


Stinger PRO Series Speaker Wire

Stinger PRO Series Speaker Wire

Priced per foot (16 Gauge)

Item #: 541SPW516B


T-Spec 12-gauge Speaker Wire

T-Spec 12-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW12WB1


Boom Mat 4

Boom Mat 4" Speaker Baffles

Protect your speakers
Regular and slim-line sizes (Slim-line: 2-1/4" depth)

Item #: 696B050311


Add to Cart

XTC 4" Speaker Baffles

Protect your speakers (Slim-line: 2-5/8" depth)

Item #: 237XT42


Add to Cart
Metra Crimp Tool and Connectors

Metra Crimp Tool and Connectors

Package contains crimp tool and over 150 pieces

Item #: 120CRIMPKT


Add to Cart
S&G Tool Aid 87615

S&G Tool Aid 87615

Window and Door Clip Removal Tool

Item #: 18187615


S&G Wire Cutter/Stripper Tool

S&G Wire Cutter/Stripper Tool

Cuts and strips 12- to 22-gauge wire

Item #: 18119100


Add to Cart
S&G Tool Aid 87650

S&G Tool Aid 87650

Door Trim and Panel Removal Tool

Item #: 18187650


Bojo Trim Panel Tools

Bojo Trim Panel Tools

Set of 6 pry tools — helps remove interior and exterior trim and door panels

Item #: 126CR6NGL


Add to Cart
Spec Tools SQR-200a Squeeze Wrench

Spec Tools SQR-200a Squeeze Wrench

Narrow space ratchet kit with 18 sockets

Item #: 180SQR200A


Add to Cart
Skewdriver Pro SPK4042

Skewdriver Pro SPK4042

Ratcheting straight and offset screwdriver set with 40 bits (Skewdriver Pro with ratchet handle, pictured)

Item #: 180SPK4042


Add to Cart
Install Bay IB35400

Install Bay IB35400

Premium door panel and trim tool

Item #: 12035400

Add to Cart
Bojo Trim Panel Tools

Bojo Trim Panel Tools

Set of 6 pry tools — helps remove interior and exterior trim and door panels

Item #: 126CR6LNGL


Add to Cart
Bass Blockers

Bass Blockers

Pairs (300 Hz cut-off)

Item #: 127BB300A2


Add to Cart