Definitive Technology DI 5.5S

Remarkably smaller than competing 5.25” models, the DI 5.5S is nearly invisible in your ceilings or walls. With a patented BDSS™ midrange/woofer and the same tweeter technology as our top floorstanding speakers, the DI 5.5S packs a dynamic punch from a tiny package. Suddenly, it’s cool to be square.

  • Room-filing Fidelity
  • Clear, Clean, and Detailed
  • Tailored to Your Space


Environmental EQ fine-tunes the highs for any space

Adjust the Environmental EQ switch to customize tweeter output for your listening environment. Engage the [+] setting to boost treble in sound-absorbing rooms, or the [–] setting to reduce treble in lively rooms. Leave in the Center position for rooms with average reflectivity.


Pivoting Tweeter for controlled directivity

The ultralight, rigid construction of DI Series aluminum dome tweeters enables them to play significantly higher frequencies than we can hear, enabling optimum linearity within the range of human hearing. The DI 5.5S features a pivotable tweeter for clean, sparkling, distortion-free highs, with dispersion customizable to your space.


Exclusive BDSS™ midrange/bass woofers

For more bass in less space while keeping midrange detailed and responsive, the DI 5.5S’s 5.25” mid/bass woofer leverages our exclusive Balanced Double Surround System (BDSS™). The double butyl rubber surrounds produce a much greater cone excursion than other comparably sized drivers. And the DI 5.5Ss rigid PolyStone™ basket provides a sturdy launching pad for the powerful excursion.

With BDSS drivers, you’ll enjoy superior midrange/bass dynamics and detail in packages sized for stealth.


Acoustic Wizardry for the details that make the difference

The DI 5.5S features a sophisticated adjustable crossover network with custom, high-precision components for superior sonic purity.

Surrounding the BDSS driver is a specially-contoured AeroRing™ that precisely distributes natural, well-balanced sound by minimizing diffraction.

The Axially-Aligned configuration of the tweeter with the woofer provides broader sound dispersion and more natural balance.


All the Stealth none of the complexity

Hidden flange architecture is fantastic for décor, because the nearly border-free design virtually disappears into walls and ceilings. What isn’t fantastic is the typical installation complexity. However, DI Series hidden flange designs are as easy to install as traditional flanged flush-mount speakers, and don’t require custom Sheetrock or spackle skills to install the practically invisible look.


Paintable Magnetic Grille for the final custom touch

All DI Series speaker grilles and grille frames are paintable, with easy step-by-step instructions. Once you have your perfect look, powerful neodymium magnets attach the grilles to the speakers for a secure, tool-free finish. 


A Disappearing Act for every installation

Whatever the setting—residential or commercial, music room or home theater—DI Series has designed a disappearing act ready to entertain you. From round or square ceiling speakers, to in-wall speakers, to Bipolar surround speakers, to in-wall subwoofers, DI Series is ready to rock a venue of any size—invisibly. Mix and match as you please, confident that you’ll always enjoy Definitive Technology’s legendary speaker voicing.

Included Accessories1x Wall Mounting Template
1x Paintable Magnetic Grille
Carton 1 (W x H x D) ; Weight230.1 x 155.7 x 230.1mm (9.06″ x 6.13″ x 9.06″) ;
2.72kg (6 lbs)
In-Wall Speaker
Qty Included1
Depth92.2mm (3.63″)
Weight1.72kg (3.8 lbs)
Grille Dimensions (W x H)187.5 x 187.5mm (7.38″ x 7.38″)
Dimensions (W xH)160.3 x 160.3mm (6.31″ x 6.31″)
Audio Inputs
Speaker Inputs1x Pair of Heavy Duty, Spring Loaded – na
Total Frequency Response28Hz → 30,000Hz
Nominal Impedance Range8 ohms
Max Sensitivity (1W @ 1m)89dB
A/V Receiver Crossover SettingsSmall (80Hz)