Alpine Type-R Loaded Enclosure (SBR-S8-4)

Ported Enclosure With One 8" Type-R Subwoofer

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List price $300.00

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Alpine Type-R Loaded Enclosure (SBR-S8-4)



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Alpine Audio Store

Subwoofer Features:

  • Loaded Enclosure With One 8" Type-R Subwoofer
  • Power Handling:
    • Peak: 1000 watts
    • RMS: 350 watts
  • Recommended power range: 150 - 350 Watts RMS
  • Nominal Impedance: 4 Ohms
  • Two-piece structural parabolic Kevlar reinforced pulp cone
  • High amplitude multi roll Surround
  • Progressive Conex spider design
  • Compound radius curve pole geometry
  • 1.5" high-temperature 4-layer dual voice coils
  • Frequency response: 30-200 Hz
  • Sensitivity: 84 dB
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Enclosure Features:

  • Ported
  • 3/8" medium-density fiberboard construction
  • Carpet protects enclosure from nicks and scratches
  • Metal grille protects the sub
  • Dimensions: 6-5/8"D x 11-3/8"H x 19-1/4"W

Subwoofer Specifications

Subwoofer Series
Each subwoofer manufactured is part of a series. This is the name of the subwoofer's series.
Type-R (Alpine)
Subwoofer Size
Refers to the diameter of the subwoofer, measured in inches.
Voice Coil(s)
Dual voice coil subs have more wiring flexibility than single voice coils subs; however, single voice coil subwoofers provide easier hookup options for wiring multiple subwoofers in parallel or series. You may also run a dual voice coil (DVC) sub in parallel, series, or combination. A quad voice coil has four voice coils and is equal to two dual voice coil subwoofers as far as wiring goes.
Impedance (Per Voice Coil)
The load value (in ohms) that the speakers present to the amplifier per voice coil - the amount of resistance to the current flow. This is a key specification as subs wired in parallel or low impedances can create problems with your amplifier and potentially void all warranties. We encourage you to ask our support department prior to purchase if you do not understand which impedance level will suit your application best.
4 ohms
RMS Power Handling
The RMS power is the amount of power the speaker requires to operate safely and properly. RMS Power Handling refers to the amount of power a speaker can handle on a continuous basis. We recommend powering your speakers or subwoofer with 80%-120% of its recommended RMS rating. The RMS power handling specification is typically rated per speaker unless otherwise noted.
350 watts
Peak Power Handling
Peak power handling refers to the amount of power a speaker can handle during a brief musical burst. The RMS power range figure is a much more reliable rating for determining the speaker's power requirements. The Peak power handling specification is typically rated per speaker unless otherwise noted.
1000 watts
Woofer Composition
Lightweight woofer cone materials are essential for efficient operation. Poly cones produce exceptional sound and are sturdy against various changes in temperature. Paper cones are very efficient, and when treated for moisture resistance, will perform at a high level. Poly refers to polypropylene, which is thermoplastic or fibers that are polymers of propylene. IMPP refers to injection molded polypropylene, a commonly used process and material in speakers.
Woofer Surround
A speakers surround is part of the suspension system. The surround protects the cone and prevents it from being displaced as it flexes out from the basket. It is usually made of a durable material like treated foam or rubber in order to withstand the strenuous job of producing bass frequencies.
Santoprene Rubber
An efficiency or sensitivity rating tells you how effectively a speaker converts power into sound. The higher the number, the more efficient the speaker and the louder it will play with the same input power. An efficient speaker helps you maximize your available power. Most sensitivity ratings measure the speaker's output with 1 watt of input, 1 meter from the speaker. Some speakers' sensitivity is measured with 2.83 volts of input, instead of 1 watt.
Efficiency (1w/1m) is not an accurate indicator of a subwoofer's output capability and should not be used as a comparison to other speakers or subwoofers to determine which one is "louder".
84 dB
Frequency Response
The range of frequencies the speaker will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
30 - 200 Hz

Enclosure Specifications

Box Type
Represents the style of the enclosure. Be sure to purchase the appropriate enclosure type and internal volume that will be compatible with your subwoofer's recommendation.

Sealed - Sealed boxes are those that have no holes or vents in it. The only hole in a sealed box is where the subwoofer is installed. Smaller sealed boxes require more power than a larger sealed box. They provide a tight, accurate bass, while the larger sealed enclosures provide a "boomier" and louder bass.

Ported / Vented - Ported/Vented Enclosures provide an even boomier, louder bass, but less accurate then a small, sealed box. Ported enclosures typically require more airspace per sub and also less power output from an amplifier to perform correctly.

Bandpass - Bandpass enclosures make subwoofers perform efficiently, but loose. The bass is not as "boomy" as a ported enclosure nor as punchy as a sealed enclosure. Bandpass enclosures work well with lower to mid-level subwoofers.
Vented / Ported
Number of Subs/Speakers
This value represents the number of speakers or subwoofers that the enclosure accommodates.
Box Style/Shape
The box style or shape refers to the actual shape of the box. Square and rectangular boxes are straight-edged boxes on all sides, whereas hatchback and truck style enclosures feature an angled front or back design that allows for installation in places short on depth such as single cab pickup trucks. You can also use such enclosures in hatchback cars or other vehicles where space is a premium. Tube and cylinder shaped boxes were made popular by Bazooka and are a great option for those looking for a nice amount of bass without sacrificing lots of space. They may even fit in locations that slim truck boxes cannot fit in. If the enclosure is vehicle specific, we encourage you to read the product description to find out which vehicles the enclosure is made for.
The height of the item, measured from top to bottom, in inches.
The width of the item from left to right (side-to-side) measured in inches.
The front-to-rear depth of the item, in inches. If the item is angled or slanted, this value is the bottom measurement.
Wood Thickness
The thickness of the wood the enclosure is made of, measured in inches.
Number of Terminals
The number of terminals the enclosure has. Each terminal represents 1 positive and 1 negative.
Terminal Type
Spring clip terminals work best with bare wire connections with small-gauge speaker wire, or pin-type connectors.

Binding post terminals are a sturdier, more versatile type of speaker terminal. Because binding post terminals are are threaded, you can tighten them down against the wire or connector for a tight, clean connection. The most popular style of binding post terminals is known as a "5-way binding post". This type can accept bare wire, or any of the common speaker wire connectors. Binding posts with the option to be used with banana clips are even more versatile

Spring posts are a hybrid of the two. Instead of using a thread and "screwing" them tight, they use a spring to allow the wire to fit and tighten against the terminal.

Spring posts
Box Exterior Color
The color of the enclosure's exterior/outer finish.
Box Finish
The material used on the outside of the box. Most boxes are carpeted to prevent exterior scratches; however vinyl is popular as it can often be color-matched to a near exact look of your leather factory interior.

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating



wasnt expecting the sound it produces

September 19, 2016

so i did an install in a 1997 dodge ram ext cab truck. 6x9 kappas front 5.25 references rear along with a polk 800.4 then a pioneer gm for the alpine. tuned right this lil thing can bump for the size has great deep tone and hits lows pretty well for a n 8. u can really feel the bass inside but not so much outside which is perfect if u just want clean music. i would recommend two of these for extra thump. but overall i give this a 4.5 only kuz its a lil pricey.

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Dallas, TX

not enough bass for my SUV

August 8, 2016

This sub was pretty good for its small size. It could hit the low bass notes ok. The problem was that there just wasn't enough of it to fill my Toyota Highlander. Also, I couldn't feel the upper bass notes either, so I couldn't get it to blend with my front component speakers very well. So I am going to return this and now have an Infinity 120.9W in a 1 cubic foot sealed and this sounds so much better in my car. I can feel the bass in my seat, and it sounds much tighter, quicker, and less bloated. This may work for a smaller car but not so much in a larger SUV.

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Leander, TX

Verified Purchase

July 3, 2016

I purchased this as a recommendation from a friend. I drive a Mazdaspeed 3 and holy cow this guy awesome. As long as you tune it correctly its amazing. The quality of box and sub is great. I have this setup with Alpine Type R 6.5 and 6x7's and an Alpine PDX V9. The biggest selling point for me was the overall size and the fact I wanted everything to be an Alpine.
Also, one shout out to Customer service. When I placed my order there was one in stock, but at some point it was placed on backorder. Customer service called me on a Sunday to notify me. I called back a few days later to check the status and some had arrived a couple of days early. I really appreciated the heads up especially on a Sunday....thanks.

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Jackson, Michigan

Very nice

April 30, 2016

I was very satisfied with my new purchase. I haven't used it a lot as it is in a truck in restoring but I do have it installed and it sounds great!

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Accessory Tools and Products

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Browse 3 questions and 5 answers
Hide answersShow all answers | Sort by
Why did you choose this?
Sonic Electronix Store
Amazing bass and it will fit under the rear seat of my Tundra.
Chris R on Jun 15, 2016
My installer said it's the best for this particular car.
Jaicie K on Aug 10, 2014
Does this powered sub box need a amp kit?
A shopper on Jul 31, 2014
Best Answer: Hello,

Absolutely, sort of. The Alpine SBR-S8-4 ITSELF doesn't need the amp kit, the actual AMP you choose to power it will need an amp kit. This is because the Alpine SBR-S8-4 is NOT "powered" like you suggested, its passive.
Reply · Report · Customer SStaff on Aug 13, 2014
· Add Answer · I Have This Question Too (0)
How do I hook 2 of these subs up to one amp?
A shopper on Feb 3, 2015
Best Answer: Hello,

Don't let the design of the Alpine SBR-S8-4 confuse you. It is Still a traditional subwoofer, with a 4ohm load at the terminal. This means that if you hook up TWO together, you will get a 2ohm load at the point. So, technically, you seek a Monoblock that is providing ~600w RMS @2ohms.

You will likely find Two types of "connections" , from a given amp , and this where I will be able to answer your question directly.

-The first type of connection will be an amp that has a traditional set of terminals, one Positive (+) and one Negative (-) , like the Alpine MRV-M500 . In this scenario you will simply need to bring together the SAME polarity-wires from EACH Alpine SBR-S8-4; So Positive wire from ONE Alpine SBR-S8-4 twisted together with the Positive wire of the OTHER Alpine SBR-S8-4, this newly made single wire will then be connected to the Positive (+) of the amp. Replicate the same for the Negatives (-). Bringing the wires together is replicating a "Parallel" connection, which drops the load to 2ohms.

-The second type of connection - which is becoming more common - will be the easiest to manage, because it provides two Positives (+) and two Negatives (-) , like the JBL MS-A5001 . This scenario is pretty self-explanatory; You will simply give Each Alpine SBR-S8-4 its own output. The amp has its connections wired internally - replicating a "Parallel" connection - so it will see a 2ohm load within itself.


Alpine MRV-M500

JBL MS-A5001
JBL MS-A5001
JBL MS-A5001
Reply · Report · Customer SStaff on Feb 3, 2015
· Add Answer · I Have This Question Too (0)

Product Summary


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Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Alpine Type-R Loaded Enclosure (SBR-S8-4)

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Alpine Type-R Loaded Enclosure (SBR-S8-4)

Ported Enclosure With One 8" Type-R Subwoofer


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NVX Speaker Wire (XWS1225)

25 ft. of True 12 Gauge EnvyFlex Speaker Cable/Wire (100% Oxygen-Free Copper)


NVX Sound Dampening Trunk Kit (SDTK20)

20 Square Feet of Sound Dampening Material (Five 18" x 32" Pieces)


Car Stereo and Speaker Installation Tool Kit

Complete Car Stereo Tool Kit, Includes Voltage Test Light, Wire Stripper and More



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