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Pioneer UD-SW250D

Single down-firing sealed enclosure for 10" shallow sub

4 Reviews | 3 questions - 5 answers


Our take on the Pioneer UD-SW250D

When space is limited

Pioneer's compact UD-SW250D subwoofer enclosure will give you great bass in a limited space. At less than 6" tall, it'll fit in the cab of a pickup truck and many other challenging locations. Built with 5/8" MDF and is covered in black carpet, this small sealed enclosure offers an internal volume of 0.35 cubic feet, and its down-firing configuration delivers a deeper sound. Pioneer recommends installing the TS-SW2502S4 10" shallow subwoofer (sold separately) in this enclosure.

Product Highlights:

  • sealed down-firing enclosure for one 10" shallow subwoofer
  • 5/8" MDF (medium-density fiberboard) with black carpet covering
  • internal volume: 0.35 cubic feet
  • dimensions: 18-3/4"W x 5-7/8"H x 12"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Very well made, looks great, comes with plenty of hardware. Put a shallow mount speaker and you have a great box.

James, Santa Rosa, NM

What's in the Box:

  • One down firing enclosure for a single shallow mount 10" subwoofer
  • Installation instructions (multiple languages)
  • 2 Mounting brackets
  • Eight 1" Wood screws

Pioneer UD-SW250D Reviews

Average Customer Review(s):

(4 Reviews)

Nice well made box

James from Santa Rosa, NM on 9/25/2016

Crutchfield Customer Review (What's this?)

Very well made, looks great, comes with plenty of hardware. Put a shallow mount speaker and you have a great box.

Pros: looks and durability

Cons: NONE

perfect for the sub I chose

GRHowell from Palmer, AK on 5/20/2016

Crutchfield Customer Review (What's this?)

Just buy the pre-loaded version rather than the sub and speaker separate. It works VERY well with the Pioneer slim sub and is matched perfectly for the sound the sub produces. There is no advantage to buying them in two pieces.

Pros: Size, sound, build quality

Cons: Specific to Pioneer speaker, cost

Coutout does not fit standard 10' subs

Nick from odessa, FL on 3/10/2016

I purchased this frkm another retailer to fit a kicker sub i got from Crutchfield. The box is very nicely constructed. But the cutout for the sub is 9 3/4' and most 10' subs need a 9 1/8' cutout. I ended up having to get an adapter ring to neck down the opening which in turn defeated the purpose of being a down firing box due to the speaker now sitting 1' further out. The box was designed to be a perfect fit for the pioneer shallow subs so keep this in mind before you purchase. If you dont mjnd a little work to make it fit its a great box for a shallow sub. If not look for another box because i would not use the pioneer shallow sub just to use this box it just can not go low enough to sound like a sub should.

Pros: Good build quality

Cons: Designed by pioneer to only fit their non standard sized shallow subs. Has to be modified to fit standard subs due to cutout size.

Nice box

Lee3333 from NYC on 9/6/2014

Crutchfield Customer Review (What's this?)

Very nicely constructed box. I used it for an 8 inch standard sub, for which the air space was perfect. I made an adapter out of 1/8 inch plywood, and it sounds great.

Pros: Solid construction.

Cons: Air space a little small for a 10 inch sub. Only fits a very narrow speaker.


Hands-on research

Product Research


Compatibility: This enclosure is designed for a single Pioneer 10" shallow-mount component subwoofer, TS-SW2502S4 (item number 130TSS2502, sold separately).

Materials: The box is constructed of 5/8" MDF (medium density fiberboard). MDF resists flexing and has anti-resonant qualities.

Design: Complementing the shallow subwoofer, this enclosure provides the smallest sealed box volume recommended for the TS-SW2502S4. The UD-SW250D enclosure will fit under the seat of some vehicles. The exterior is covered with black auto carpet.

Terminals: The spring post wire terminals, located on the side of the enclosure, will accept bare wire (up to 10 gauge), pin connectors, banana plugs, and dual banana plugs. Inside the enclosure, a 15" length of speaker wire is attached to the terminal (bare wire at the other end).

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 verify what’s in the box, 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.

Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

quality [ Dan  Mar 14, 2017 ]
New pickup has shallow area under back seat. Old box and sub where too tall. [ Jeff  Mar 09, 2017 ]
Down ward box like I need [ Brandon  May 15, 2016 ]
space. [ Lino  Jan 22, 2016 ]

3 questions already asked

i'm not sure because I am not familiar with that sub. you will need to check the dimensions such as the mounting depth and the mounting diameter. This box met the mounting depth for the kicker comp RT 10 inch woofer, but I mistakenly did not check the mounting diameter. The hole was too big so my subwoofer would not mount correctly and I had to return it to crutchfield. [ VINCENT  Aug 23, 2017 ]
Nope - it's made specifically for a Pioneer sub. The hole is a different size than a standard 10" sub. [ Gary  Aug 23, 2017 ]
None. The free air inside this enclosure is very limited to begin with and sticking an amp in there would make it even worse. Secondly trying to run wires through the box and getting the holes to seal will be a nightmare inducing task. Also the amp would not be able to cool properly and will over heat quickly.. [ Shayne  Aug 08, 2015 ]
Your not gonna be able to fit the amp inside. [ Dylan  Aug 08, 2015 ]