KICKER 47KBRW8 8" Passive Radiator + 43CWR8G Subwoofer Grille | DIY Boombox Build Kit

Build Your Own Custom Portable Boombox With KICKER Components

Bring your DIY audio project to life with the KICKER 47KBRW8 8-inch Bass ReFLEX Passive Radiator and 43CWR8G Subwoofer Grille Bundle. Designed for custom speaker enclosure projects, this KICKER component kit gives builders two essential parts for creating a personalized portable boombox, DIY Bluetooth speaker enclosure, or custom bass enclosure.

Whether you're building a portable party speaker for the backyard, a custom Bluetooth boombox for camping and tailgating, or a unique homemade speaker cabinet, this bundle helps you get started with quality KICKER components.

The KICKER 47KBRW8 passive radiator is designed to work with a compatible active subwoofer in a properly designed enclosure. It helps produce enhanced low-frequency output in compact enclosure designs without requiring a conventional port. The included 43CWR8G grille adds a protective finishing touch for a compatible 8-inch KICKER subwoofer.

Design your own enclosure, choose your preferred materials and finish, and create a custom speaker build that fits your style.

What's Included

• 1 × KICKER 47KBRW8 — 8-inch Bass ReFLEX passive radiator

• 1 × KICKER 43CWR8G — 8-inch KICKER subwoofer protective grille

This bundle does not include an active subwoofer, full-range speakers, amplifier, Bluetooth receiver, battery, enclosure, or other components required for a complete portable boombox.

KICKER 47KBRW8 8-Inch Passive Radiator Highlights

• 8-inch round Bass ReFLEX passive radiator

• Designed for custom subwoofer enclosure projects

• Helps enhance low-frequency output in compact enclosure designs

• Provides an alternative to a conventional ported enclosure

• Custom-weighted design for use in compatible enclosure systems

• Supports creative DIY speaker and portable boombox builds

• Ideal for builders designing a custom cabinet around compatible KICKER subwoofer components

KICKER 43CWR8G 8-Inch Subwoofer Grille Highlights

• Protective grille for compatible 8-inch KICKER subwoofers

• Helps shield the subwoofer cone from accidental contact

• Useful for custom speaker cabinets and DIY boombox enclosures

• Provides a finished appearance for compatible subwoofer installations

• Designed for compatibility with specified KICKER 8-inch subwoofer models

Ideal for DIY Boombox and Portable Speaker Projects

One of the most exciting parts of building your own boombox is being able to choose the enclosure size, materials, layout, finish, and electronics. This KICKER bundle gives you two components to incorporate into that custom design.

Use it as part of a project such as:

• DIY portable boombox

• Custom Bluetooth boombox

• Homemade Bluetooth speaker

• DIY portable party speaker

• Custom battery-powered speaker project

• DIY outdoor speaker cabinet

• Portable tailgate speaker

• Garage or workshop speaker build

• Custom subwoofer enclosure

• Compact bass-reflex or passive-radiator speaker project

The possibilities depend on the enclosure design and the additional speakers, subwoofer, amplification, power supply, and audio electronics you select.

Why Use a Passive Radiator in a Custom Boombox?

A passive radiator can help a properly designed speaker enclosure produce deeper low-frequency output without using a conventional tuned port. This can be particularly useful for DIY portable speaker builders who want to balance bass performance with limited enclosure space.

The 47KBRW8 is not a powered speaker or a replacement for an active subwoofer. It works alongside a compatible active subwoofer, with enclosure volume, subwoofer parameters, radiator tuning, and available excursion all affecting the finished system's performance.

Customize Your Build Your Way

This bundle is designed for builders who want flexibility instead of purchasing a preassembled speaker cabinet.

Build a wooden enclosure, create a portable cabinet with carrying handles, integrate a Bluetooth receiver, or design a custom battery-powered sound system. You can choose the components and appearance that suit your project.

For a complete portable boombox, you will need to select the appropriate active subwoofer, full-range speakers, amplifier, audio source or Bluetooth receiver, power supply or battery, and enclosure materials. Additional wiring, charging hardware, switches, and protection components may also be required.

Important: A passive radiator does not produce sound on its own. The completed system's output and bass response depend on the active subwoofer, amplifier, enclosure, and tuning.

Product Specifications

KICKER 47KBRW8

• Brand: KICKER

• Model: 47KBRW8

• Product Type: Passive radiator

• Size: 8 inches

• Series: Bass ReFLEX

• Application: Custom subwoofer enclosure and DIY speaker projects

• Active Subwoofer Required: Yes

KICKER 43CWR8G

• Brand: KICKER

• Model: 43CWR8G

• Product Type: Subwoofer grille

• Size Class: 8 inches

• Application: Protection for compatible KICKER subwoofers

• Subwoofer Included: No

Frequently Asked Questions

Can I use this bundle to build my own Bluetooth boombox?

Yes. The passive radiator and grille can be incorporated into a custom boombox project. You will also need compatible speakers, an active subwoofer, an amplifier, a Bluetooth receiver or other audio source, a suitable power source, and a properly designed enclosure.

Does the KICKER 47KBRW8 produce sound by itself?

No. It is a passive radiator, not an active speaker or subwoofer. It must work with a compatible active subwoofer in a properly designed enclosure.

What does the passive radiator do?

A passive radiator works with the active speakers and enclosure to enhance low-frequency output without requiring a conventional port. Its performance depends on the enclosure design and tuning.

Does the bundle include the subwoofer?

No. This bundle includes the KICKER 47KBRW8 passive radiator and 43CWR8G grille only. The active subwoofer and other electronics must be purchased separately.

Can I use this for a battery-powered portable speaker?

Yes, as part of a properly designed complete system. You will need an appropriate amplifier, battery, charging and protection components, and compatible speakers. 

What subwoofer should I pair with the 47KBRW8?

KICKER recommends a compatible 8-inch CompRT or CompVT subwoofer in approximately 0.4 cubic feet of internal air space. Confirm the exact model specifications and enclosure requirements before building.

Expert Recommendation

For DIY audio enthusiasts, the KICKER 47KBRW8 and 43CWR8G bundle is a useful starting point for a custom portable boombox or compact subwoofer enclosure project. The passive radiator offers enclosure-design flexibility, while the matching grille provides protection.