Garage
Shop

See all parts that fit your 1990 Imperial

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
NVX - Worth the Envy - Direct to Consumer Car Audio

Loading...
Limited time!
46CSC654 main

Kicker CSC65 (46CSC654)

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

254
-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

UTE-73BT main

Alpine UTE-73BT

Single DIN Digital Media Receiver with Bluetooth

44
-16.69%

$149.95

List price $180.00

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

214
-9.16%

$109.00

List price $119.99

CV15BT main

Cerwin-Vega CV15BT

Single Din Digital Media Receiver with Bluetooth

3
43DSC6504 main

Kicker DSC650 (43DSC6504)

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

72
-10.53%

$84.99

List price $94.99

Club 322F main

JBL Club 322F (SPKCB322FAM)

150W Peak (50W RMS) 3.5" Club Series 2 Way Coaxial 3-ohm Speakers

1
-27.29%

$79.95

List price $109.95

REF6532IXAM main

Infinity Reference REF6532IXAM

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

22
-20.01%

$119.95

List price $149.95

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

GX608C main

JBL GX608C (GX608CAM)

420W Peak (140W RMS) 6.5” GX Series 2 Way 2.3-ohm Component Speaker System

7

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

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 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

Single 12” small

Tru Spec Single 12" (1447TS)

• 12" Single Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Total box volume: 1.75 cubic feet
• Compatible for Sundown SA12V2 subwoofers (Sold separately)

(9)

$174.99

List price $289.99

NE101P small

NVX NE101P

• 10" Single Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Internal box volume: 1.50 cubic feet
• Premium Black Carpet with Black NVX Logo

(39)

$84.99

List price $101.99

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

NE151P small

NVX NE151P

• 15" Single Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Internal box volume: 3.50 cubic feet
• Premium Black Carpet with Black NVX Logo

$149.99

List price $179.99

Single 15” small

Tru Spec Single 15" (1466VG)

• 15" Single Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Total box volume: 3 cubic feet
• Compatible for Sundown SA 15V2 subwoofers (Sold separately)

(5)

$219.99

List price $279.99

2x12supb small

Tru Spec 2X12SUPB (1545KE)

• 12" Dual Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Total box volume: 3.50 cubic feet
• Computer-designed CNC cut

(6)

$299.99

List price $399.99

S15supb small

Tru Spec S15SUPB

• 15" Single Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Computer-designed CNC cut
• Total box volume: 3.50 cubic feet

(5)

$299.99

List price $399.99

12TKDV small

Atrend 12TKDV

• 12" Dual Truck Ported Subwoofer Enclosure
• 3/4" Medium Density Fiberboard (MDF) construction
• Miter and Dado construction
• Premium carpet finish
• Silver spring loaded terminal cups
• Glued and braced with fasteners
• Total box volume: 0.69 cubic feet

(3)

$149.95

List price $209.99

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




VIBE415 small

Lanzar VIBE415 Viberant Series

$139.99

List price $259.99

G1800.4 small

Rockford Fosgate Punch 800.4

$379.99

List price $599.99

MPC-I306-6C-5M small

Monster Cable MPC I306 6C-5M

6-Channel, 16.54 ft. (5 meters) 306 XLN« Standard Car Audio Interconnect RCA Cables (I306XLN-6C-5M, I306 XLN 6C-5M)

(8)

$79.99

List price $99.99

TS-A523FH small

Pioneer TS-A523FH

640W Peak (110W RMS) 5.25" A-Series 2-way 4-ohm Coaxial Car Speakers

$99.99

List price $120.00

LC-BMRC-01 small

Axxess LC-BMRC-01 Wiring Interface

Install a new car stereo and retain the safety warning chimes in select 2006-2016 vehicles from BMW, MINI

$54.99

List price $99.99

52CVT104_2 small

Kicker CVT104 (52CVT104) - Pair

750W Peak (375W RMS) 10" CompVT Series Single 4-ohm Shallow Subwoofer

$359.98

List price $399.98

APPA183 small

Panasonic APPA183 20 Cup Rice Cooker and Steamer

Panasonic Srms183 White 20 Cup Rice Cooker and Steamer

$137.99

List price $258.00

T1675-S small

Rockford Fosgate Power T1 T1675-S

400W Peak (200W RMS) 6.75" Power Series 2 Way Component 4-ohm Speaker System

(49)

$359.99

List price $359.99

MVPA4_XUBT3 small

NVX MVPA4 Micro Amp + XUBT3 Universal Bluetooth Controller

400W RMS 4-Channel Bridgeable Micro Class D Compact Amplifier with Bluetooth Audio Receiver & Volume/Playback Controller

$319.98

List price $499.98

Related Searches


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

2014 Audi S5

1990 Chrysler Imperial

2014 Dodge Avenger

2007 Buick Rainier

2009 Dodge Viper

2009 Lexus SC430

2014 Smart Fortwo

2022 Audi e-tron S

2004 BMW 645Ci

1991 Saab 900

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.