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Two black rubber passive radiators, 70mm outer diameter, 55mm inner diameter, 4.5mm high, metal centre plate

Unique-Bargains

Unique-Bargains 3" 70mm Passive Radiator 2Pcs 55mm ID 4.5mm H

SKU CH-5XW1-3ESJE

Two 70 mm passive radiators with 55 mm inner diameter and 4.5 mm height extend low-frequency response without port noise

  • TypeSpeakers
  • Enhances deep bass by harnessing trapped enclosure sound
  • Eliminates port turbulence noise for cleaner low-frequency output
  • Reduces active driver excursion through shared acoustic load
  • 70 mm outer diameter fits standard 3-inch speaker cutouts
  • 55 mm inner diameter and 4.5 mm height match common repair specs

Two 70 mm Passive Radiators for DIY Enclosures

This pair of passive radiators is designed for speaker builders who want to extend low-frequency response without using a ported tube. Each unit has a 70 mm outer diameter, a 55 mm inner diameter and a 4.5 mm profile, and the set includes two pieces for stereo or dual-driver cabinets.

Suited for Compact Sealed Boxes.

The rubber surround and metal centre plate let the radiator move sympathetically with the active driver, reducing air turbulence and eliminating port noise at high volumes. Builders who need a traditional vented alignment or who require a larger radiating area for higher output should consider alternative solutions.

70 mm Outer Diameter Determines Fit

The 70 mm outer dimension is the critical measurement for cutout planning and enclosure volume calculations. Verify that your cabinet design accommodates this diameter and the 55 mm inner clearance before ordering.

Highlights

  • Enhances deep bass by harnessing trapped enclosure sound
  • Eliminates port turbulence noise for cleaner low-frequency output
  • Reduces active driver excursion through shared acoustic load
  • 70 mm outer diameter fits standard 3-inch speaker cutouts
  • 55 mm inner diameter and 4.5 mm height match common repair specs

Specifications

BrandUnique Bargains
TypeSpeakers

Questions about this item

How does the 70 mm outer diameter affect low-frequency output once the radiator is installed in a cabinet?

The 70 mm diameter sets the moving surface area that couples with the enclosure air spring, allowing the passive radiator to reinforce bass below the driver's natural roll-off without port turbulence.

What mounting pattern does the 55 mm inner diameter require for a secure fit?

The 55 mm inner diameter fits over a 55 mm bolt circle or baffle cut-out, so the metal centre plate can be screwed or bolted directly to the cabinet panel.

How much baffle thickness does the 4.5 mm overall height allow for flush mounting?

At 4.5 mm total height the radiator sits nearly flush, so it suits baffles up to about 4 mm thick without protruding beyond the front surface.

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