Garage
Shop

See all parts that fit your 1990 Escort Pony

Custom Enclosures 12" Round Hole, Long Rear Slot Ported Enclosure

121RP, 121KPRO

highlight-star-icon

12" Round Hole, Rear Ported Subwoofer Enclosure • Mounting depth: 10-3/4" • Box volume: 2.80 cubic feet • Total port volume: 0.30 cubic feet

Learn more about the 121kpro

Good news and a little bad...

This item has been discontinued

But you may be interested in the newest model that's available.

sqpxl112 thumbnail

Ground Shaker SQPXL 1 12

OUR PRICE: $69.95

View item

Loading...
Limited time!
46CSC654 main

Kicker CSC65 (46CSC654)

600W Peak (200W RMS) 6.5” CS Series 2 Way Coaxial 4-ohm Speakers

122
-33.36%

$79.96

List price $119.99

Limited time!
Club 622 main

JBL Club 622

360W Peak (120W RMS) 6.5" Club Series 2-way Coaxial 3-ohm Speakers

5
-28.58%

$99.95

List price $139.95

43DSC6504 main

Kicker DSC650 (43DSC6504)

480W Peak (120W RMS) 6.5” DS Series 2-way 4-ohm Coaxial Car Speakers (DSC6504)

28
-10.53%

$84.99

List price $94.99

DB652 main

Polk Audio DB652 (DB 652)

600W Peak (200W RMS) 6.5" DB+ Series 2 Way Coaxial 4-ohm Car, Marine and Powersports Speakers

12
-9.16%

$109.00

List price $119.99

PNW-65CS2 main

AudioControl PNW-65CS2

250W Peak (200W RMS) 6.5″ PNW Series 2 Way Component 3-ohm Speakers

4
-5.90%

$319.00

List price $339.00

MPK 163.3 main

Hertz MPK163.3

600W Peak (300W RMS) 6.5" Mille PRO Series 3-way 4-ohm Component Speaker System

2
-14.89%

$999.99

List price $1175.00

NSP65 main

NVX NSP65

540W Peak (180W RMS) 6.5" N-Series 2 Way Coaxial Car Speakers

93
-35.19%

$69.99

List price $107.99

Club 522F main

JBL Club 522F (SPKCB522FAM)

270W Peak (90W RMS) 5.25" Club Series 2 Way Coaxial 3-ohm Speakers

-42.29%

$74.99

List price $129.95

XED62 main

Cerwin-Vega XED62

600W Peak (70W RMS) 6.5" XED Series 2-Way Coaxial 4-ohm Speakers

15
-16.67%

$49.99

List price $59.99

PH654 main

Cerwin-Vega PH654

600W Peak (300W RMS) 6.5" PRO Series Full Range Coaxial 4-ohm Speakers

2
-16.67%

$189.99

List price $227.99

Description


  • 12" Round Hole, Rear Ported Subwoofer Enclosure
  • Mounting depth: 10-3/4"
  • Cutout diameter: 11-1/8"
  • Box volume: 2.70 cubic feet
  • Total port volume: 0.32 cubic feet
  • Dimensions: 15"D x 30-1/4"W x 15"H
  • 30 Day return policy

Product history:

Ground Shaker SQPXL 1 12 thumbnail
(newest, current model)
Custom Enclosures 121KPRO thumbnail
(previous model, replaced by Ground Shaker SQPXL 1 12)

Best selling similar products

Dual 12in P small

Tru Spec Dual 12in P (1460YX)

• 12" Dual Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Total box volume: 3.50 cubic feet
• Compatible for Sundown SA 12V2 subwoofers (Sold separately)

(6)

$234.99

List price $299.99

1SV12B small

Single 12" Vented MDF Subwoofer Enclosure (Belva 1SV12B)

• Single 12" Vented MDF Enclosure
• Holds one 12" subwoofer
• 3/4 MDF (Medium Density Fiberboard) Construction
• Durable black carpeting
• Gold Terminals
• Internal Box Volume: 1.8 cubic ft.

(123)

$79.99

List price $95.99

Dual 10” small

Tru Spec Dual 10" (1459UN)

• 10" Dual Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Total box volume: 2 cubic feet
• Compatible for Sundown SA10V2 and similar subwoofers (Sold separately)

(5)

$184.99

List price $299.99

Specifications & Details


Box/Enclosure specifications
Subwoofer Size
12"
Subwoofer Cutout Shape
Round / Circle
Box Type
Ported
Number of Subwoofers
1
Box Style/Shape
Square/Rectangle
Cutout Diameter or Length
11-1/8"
Maximum Speaker Depth
10-1/2"
Total Box Volume
2.7 cubic feet
Wood Thickness
3/4"
Number of Terminals
1
Terminal Type
Binding posts (banana clip ready)
Box Exterior Color
Black
Box Finish
Carpet
Port Details
Number of Ports
1
Port Diameter
13-1/4"
Port Length
17"
Warranty and Return Policy
Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Item Details


Manufacturer:

Model Number:

121KPRO

Weight:

51.00lbs

Internal SKU:

121kpro

Internal Product ID:

14600

Customer Ratings & Reviews


Custom Enclosures 12

5 star
75%
4 star
15%
3 star
10%
2 star
0%
1 star
0%



Durability
4.6
Value
4.6
Features
4.5
Design
4.6
Usability
4.8

Customer Reviews

Sort by:

Loading...

Best Bass Pounding Box EVER!!

I have the Hifonics Brutus OLM1612 sub enclosed in this bad boy box and it pounds like no other. Its a very solid box and is true to the dimensions and box volume...I would HIGHLY suggest buying this box to my friends, family or strangers (plus Sonic has the best shipping, was super fast). If you want an all around great looking, great sounding and great performing box...then just click.."+ Add to Cart" button and let the pounding begin!!

By Ryan on August 9, 2010

5 found this helpful


Good prefab box

Box does look clean and nicely built. Put my american bass 12" xfl in it and it pounds! Had to make cut out a lil bigger for my sub to fit but not a big deal recommended for anyone who can't build their own

By Fredy on March 3, 2010

5 found this helpful


Nice Box

dropped my FiQ12 into it...well built and very solid looks really clean with the black carpet

By Blake on December 28, 2009

5 found this helpful


12'' Ported Box

I recenly purchased this box along with the power acoustiq mofo 122x. I tried the mofo in a box i had for two kicker comp 12's, and it didnt sound up to par. When i put it in this box, its like it got 10x louder. And it hits the lows perfect like i wanted. Cant really use my rearview or sideview mirrors.

The box is well built and sturdy. I drive a 99 blazer 2 door btw.

By Cobbsy on January 4, 2012

4 found this helpful


awesome box for the money

I have my Alpine Type R in this and it pounds! I had it in a .8cu ft box I got at bestbuy and it was too small and choked it out, the whole car vibrates now and hits lower notes better, gets those real low ones i love :) only thing I don't like is the port is on the side so its kind of against the trunk, but its far back enough to work so if you have a small car like a civic you just need to measure =]

By Greg on February 27, 2011

4 found this helpful


Destroyed

I got this box for my 12" Fi BTL and it's a great box while it lasted. Now my box smacks wood and sounds horrible i had to put 5 screws to keep it from making that sound. this box is perfect unless you have something pushing to much power like my sub

By SPL on September 27, 2010

4 found this helpful


booom!

This box kicks hard! It makes my JL Audio 12w3v3 hit so harder than it did before in my old 1.3 cu ft ported box. I love it. I would definitely recommend this box and website to anybody. Thanks Sonic

By fern on March 19, 2010

4 found this helpful


Very Nice!

Solidly built, and Creates nice bass. Very good price also. Nice color, and nice to have built-in terminals.

By Nick on September 16, 2008

4 found this helpful


Great Buy! Custom Enclosures 12" Round Hole, Long Rear Slot Ported Enclosure

Bought a big enclosure in order for it to fit exactly in my trunk and wouldn't move and slam around because of my driving :p. I really love it, bass kicks great even of how big it is. It is ported so it helped out from the size. Great Buy! Great quality! Recommend!

By Elder on February 26, 2013

3 found this helpful


Good Deal

Used this box for a Fi Bl 12 and it slammed hard. The tuning frequency is around 41-42 hz so the lows arent very loud and the sound quality isnt always the best but its good for a prefab box. Good box if you dont mind that high of a tuning.

By Main Bull on April 6, 2011

3 found this helpful




XK8Z small

db Link XK8Z

8 Gauge X Series Amplifier Wiring Kit with AGU Fuse Holder

(9)

$15.99

List price $25.99

ATX2000.1 small

Autotek ATX2000.1 (Factory Refurbished)

2000W Max 1-Channel Monoblock Class AB ATX Series Amplifier

$69.95

List price $249.95

Related Searches


Save up to 10 different vehicles in your garage
Vehicle
Store
Delete

1990 Ford Escort Pony

1983 BMW 320i

2003 Toyota Matrix

2018 Ford Explorer

2008 Audi A4

2013 Nissan Versa

2008 Volvo C70

1999 Acura RL

1972 Mercury Capri

2011 MINI Countryman

Add vehicle Clear all vehicles
Where to find vehicle info
Are you sure you want to clear your garage?
This action cannot be undone. Confirm
This page was not designed for products.
If you continue, you will be redirected to a category customized for your vehicle. Continue
Loading...
Identify your vehicle and submodel details
  • Owner's manual
  • Vehicle's insurance card
  • Vehicle registration
  • Vehicle produced after 2005: Inside driver's side door
  • Vehicle produced before 2005: Rear passenger doorjamb, glove box, center console, or engine compartment
Car Info Side Door Icon
Vehicle Registration Icon
Vehicle Insurance Icon

Modern vehicles often require specific brackets, wiring harnesses, and mounting solutions. A fit guide ensures:

  • You see only parts engineered for your exact vehicle
  • You avoid incompatible radios, speakers, or wiring
  • Installation is smoother, faster, and frustration-free
  • You get the correct accessories the first time

Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.