Does a subwoofer box make a difference?

Yes, and it is the difference between bass and noise. Without a box, the sound off the back of the cone wraps around and cancels the sound off the front, so you lose most of your low end. The box stops that cancellation and sets how the driver behaves. The same subwoofer in two different enclosures can sound like two different products.

What does a box do for a subwoofer?

The box controls the air behind the cone, which controls the driver. Sealed enclosures use trapped air as a spring for tight, accurate response. Ported enclosures use a tuned vent that reinforces output near the tuning frequency. Box volume also sets how low the sub plays and how well it stays under control at high power.

Which type of subwoofer box is best?

There is no single best type, only the right type for your goal. Sealed is best for sound quality and tight, accurate bass in a smaller box. Ported is best for maximum output and efficiency but needs more space. Vehicle-specific behind-seat boxes are best when you need factory fit without losing cargo room.

Do subs hit harder in a ported box?

Yes. A ported box is more efficient near its tuning frequency, so it plays louder than a sealed box on the same amplifier power, typically by around 3 dB in the tuned range. The tradeoff is a larger enclosure and a steeper rolloff below tuning. Choose ported for output, sealed for accuracy.

Which subwoofer box is best for deep bass?

For the deepest usable output, a ported box tuned low, usually in the low 30 Hz range, moves the most air where you feel it. If you want depth with control rather than maximum volume, a properly sized sealed box rolls off more gradually and often sounds deeper in a vehicle because cabin gain fills in the bottom octave.

What size subwoofer box do I need?

Box volume is set by the specific driver, not the cone size. Two 12 inch subwoofers can call for very different sealed or ported targets depending on their Thiele-Small parameters. Each enclosure we build is cut to its driver's published target. Model it yourself with our Subwoofer Box Calculator Suite, or send us your subwoofer and vehicle and we will match the right box.

What are your enclosures made of?

Every box is cut from Langboard Elite MDF, 48.5 pounds per cubic foot with a 200 psi internal bond, on our ShopSabre CNC routers in Tullahoma, Tennessee. Sealed variants ship with polyfill installed, and each box is prewired with 12 gauge OFC to an ABS and carbon fiber composite terminal cup with stainless hardware.

Subwoofer enclosure banner image with sub enclosures from proline x

Sealed, Ported & Vehicle-Specific

Car Subwoofer Boxes & Enclosures

Sealed, ported, vehicle-specific, and shallow-mount enclosures from 6.5 inch to 15 inch. Built and shipped from Tullahoma, Tennessee.

Best for SQ

Professional Series Enclosure Image Dynamics IDMAX 10 Sealed Box

Proline X

Proline X Enclosure | Professional Series | Fits Image Dynamics IDMAX 10" Subwoofer

Driver-specific sealed box for the Image Dynamics IDMAX 10 V4. Double-layer baffle, tuned to the driver for tight, accurate bass.

$ 249.99 $ 279.99

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Best High-Output

Proline X

Proline X P12D-P | Dual 12" Ported Subwoofer Enclosure | V3

Dual 12 ported enclosure for maximum efficient output. V-groove and dado joinery in Langboard Elite MDF.

$ 269.99

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Best for Tight Spaces

Car audio subwoofer enclosure with two visible subwoofers on a white background

Proline X

Proline X Micro Series Dual 12" Sealed Enclosure | Built for ResoNix GUS-12

Micro Series stack-fab enclosure for shallow, under-seat, and behind-seat installs where mounting depth is tight.

$ 349.99

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Best Value

Proline X

Proline X P12D-S | Dual 12" Sealed Subwoofer Enclosure | V3

Dual 12 sealed enclosure that covers most builds. Accurate, controlled bass, prewired and ready to drop in.

$ 219.99

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Shop the Lineup

Proline X Micro Series 12" Sealed Enclosure - Fits Arc Audio SW12 - Proline X Subwoofer Enclosures for car audio systems

Proline X M12-S ARC SW

Proline X M12-S ARC SW | Single 12" Sealed Subwoofer Enclosure | Built for Arc Audio SW12

$ 299.99

In stock and ready to ship!

Subwoofer in a black enclosure on a gray background

Proline X PO ID 12-S I

Performance Optimized Sealed 12" Enclosure | Image Dynamics IDQ 12

$ 299.99

In stock and ready to ship!

Black subwoofer enclosure with visible driver on a white background

Proline X M10-S Gus

Proline X Micro Series 10" Sealed Enclosure | Built for ResoNix GUS-10

$ 249.99

In stock and ready to ship!

Professional Series Enclosure JL Audio 13w7 Ported Box

Proline X Pro JL 10W7

Proline X Enclosure | Professional Series | Fits JL Audio 10w7 Subwoofer

$ 399.99

In stock and ready to ship!

Proline X M10D-S WAV

Proline X Micro Series Dual 10" Sealed Enclosure - Fits Wavtech thinPRO 10

$ 299.99

In stock and ready to ship!

Proline X Enclosure X Series Fits Kicker Solo X 8-inch Subwoofer Dual - Proline X Subwoofer Enclosures for car audio systems

Proline X Pro10D-P KIK

Proline X Enclosure | X Series | Fits Kicker Solo X 10" Subwoofer | Dual

$ 749.99

In stock and ready to ship!

Two car audio subwoofer enclosures on a white background

Proline X P8D-S III G

Proline X P8D-S | Dual 8" Sealed Subwoofer Enclosure | V3

$ 169.99

In stock and ready to ship!

Image Dynamics IDMAX 10 Loaded Subwoofer Enclosure (Sealed)

Proline X Pro10-S IDMA

Proline-X Sealed 10" Enclosure – Loaded with Image Dynamics IDMAX 10

$ 699.99

Last One

Ford F150 Behind Seat Subwoofer Enclosure with Alpine RSW10D4

Proline X VS FD1 10-S

2015-2023 Ford F-150/F-250 Behind-Seat Single 10" Enclosure – Loaded with Alpine RSW10D4

$ 959.99

In stock and ready to ship!

Proline X E12-S

Proline X E12-S Sealed Enclosure

$ 129.99 $ 159.99 18% OFF

In stock and ready to ship!

A black fabric-covered subwoofer enclosure box with a circular wood-grain front opening, showing internal wiring and a 1.0 ft net, on a solid white background.

Proline X PO12-S SI BB

Proline X PO12-S SI | Single 12" Sealed Subwoofer Enclosure | Built for Stereo Integrity SQL

$ 299.99

In stock and ready to ship!

A black double-baffle car audio subwoofer box with a textured fabric cover, showing the MDF interior and wiring through two large circular speaker cutouts.

Proline X PO12D-S SI B

Proline X PO12D-S SI | Dual 12" Sealed Subwoofer Enclosure | Built for Stereo Integrity SQL

$ 389.99

In stock and ready to ship!

Proline X Performance Wedge P12-WS III Sealed Enclosure for 12" Subwoofers Proline X

Proline X P10-S W G

Proline X Performance Wedge P10-WS III Sealed Enclosure for 10" Subwoofers

$ 159.99 $ 179.99 11% OFF

In stock and ready to ship!

Proline X M15D-S Gus

Proline X Micro Series Dual 15" Sealed Enclosure | Built for ResoNix GUS-15

$ 499.99

In stock and ready to ship!

Proline X PO ID 10-S I

Performance Optimized Sealed 10" Enclosure | Image Dynamics IDQ 10

$ 249.99

In stock and ready to ship!

Proline X Enclosure X Series Fits Dual Kicker Solo X 12-inch Subwoofer - Proline X Subwoofer Enclosures for car audio systems

Proline X Pro12D-P KIK

Proline X Enclosure | X Series | Fits Dual Kicker Solo X 12" Subwoofer

$ 1,299.99

In stock and ready to ship!

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Built Different. Built Better.

Every Proline X enclosure is manufactured in our Tullahoma, Tennessee facility using materials and construction methods that most enclosure brands don't touch.