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Definitive Technology Mythos XTR®-40 Wallspeaker

Ultra-thin multi-purpose home theater speaker

Outlet: Open Box

Item #: 735XTR40

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The perfect speaker for flat-panel TVs

Imagine you've just finished mounting your new, ultra-thin HDTV on the wall. You pop a movie into your disc player and turn on your system. You hear the first few opening chords in Return of the Jedi and...the sound is flat and tinny, more like kazoos than a full orchestra. The movie just isn't grabbing you — a sure sign that it may be time to upgrade your speakers. Check out Definitive's wall-mountable flat-panel Mythos XTR-40 speaker. It can give you the rich, cinematic sound you crave without sacrificing floor space or filling your room with bulky speakers. Use one each for your home theater's left, right, and center channels, and enjoy high-performance sound from clean-looking speakers that measure a mere 1-1/2" deep.

State-of-the-art driver design for impressively accurate sound

Using precise computer modeling and years of design experience, Definitive created incredibly thin, space-efficient "XTDD" drivers. These shallow drivers optimize every part of the speaker surface to maintain a high level of performance. The XTR-40 uses two 3-1/2" XTDD drivers, each one pressure-coupled to a low-bass radiator, for big sound from a total of four dome woofers. And at the center of the baffle is the same pure aluminum dome tweeter used in Definitive's flagship Mythos ST SuperTower® speakers. It produces extended highs, revealing nuance and shimmer without a trace of edginess.

Build an attractive XTR home theater system in your home

Thin cabinet

With a depth of only 1-1/2", this slim speaker looks great next to a flat-panel TV.

The Mythos XTR-40 comes with a wall-mounting bracket that allows for either vertical or horizontal placement, with a total installation depth of just 1-9/16" inches. The specially shaped enclosure is made of black hand-polished aluminum, and uses stiffing ribs and channels to make it rigid and resonance-free. It's such an attractive speaker, we can almost guarantee you'll get compliments on it. Put together a complete home theater system using XTR-40 speakers for your front three channels. Add on Definitive's Mythos Gem or Mythos Gem XL surround speakers for wraparound sound. And for high-impact bass, check out these Definitive subwoofers.

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Did you know?
Your new speakers will probably sound better after several weeks of use than they do right out of the box. That's because the material surrounding the woofers will loosen up, allowing the drivers to move more fully. Definitive Technology estimates a break-in period of 24 to 48 hours of playback before the speakers will deliver optimum sound quality. For more information and helpful tips, check out this article from Definitive's website about conditioning your speakers.

Product Highlights:

  • matches ultra-thin TVs 40" and up
  • frequency response 100-30,000 Hz
  • sensitivity 92 dB
  • 8-ohm impedance
  • handles up to 100 watts
  • one 1" pure aluminum dome tweeter
  • two 3-1/2" XTDD aluminum dome midrange/bass drivers
  • two 3-1/2" pressure coupled dome low-bass radiators
  • one pair of 5-way binding posts
  • aircraft-grade extruded aluminum cabinet
  • gloss black finish
  • includes wall-mounting bracket
  • dimensions: 6"W x 23-1/4"H x 1-1/2"D (without bracket)
  • warranty: 5 years
  • Our 60-day money-back guarantee

Definitive Technology Mythos XTR®-40 Wallspeaker Reviews

Hands-on research

What's in the box?

Download owner's manual

  • On-wall/On-shelf LCR loudspeaker
  • Magnetic cloth grille (installed)
  • Magnetic "Definitive" logo (installed)
  • 2 Feet stabilizers
  • 2 Mounting screws
  • C-clamp connector
  • 2 Self-adhesive rubber pads
  • Owner's Manual (Eng/Fre/Spa)
  • Online Product Registration Card
  • Horizontal MountingTemplate
  • Vertical MountingTemplate

Product Research

Overview: The Definitive Technology Mythos XTR-40 loudspeaker offers maximum versatility for your home theater and flat-panel entertainment system (perfect size for 32"-46" TV); it can be used as an on-wall or shelf-mounted Front, Center, and Surround speaker. The Mythos XTR-40 features a high-gloss aircraft-grade extruded aluminum enclosure with proprietary damping technologies to ensure total rigidity and perfectly accurate sound. It also features two 3-1/2" XTDD anodized aluminum mid/bass drivers pressure-coupled to two 3-1/2" dome low-bass radiators, and a 1" (25mm) pure aluminum dome tweeter with an acoustically contoured faceplate for excellent high frequency extension, detail, and natural smoothness.

Driver Technology
Enclosure Design
Mounting Options

Driver Technology

Pure Aluminum Dome Tweeter: The center-mounted 1" tweeter is the same hyper-definition pure aluminum dome tweeter found in Definitive's award-winning state-of-the-art Mythos ST SuperTower. The pure aluminum dome tweeter provides clarity, dynamic range, and extended high-frequency response.

XTDD Technology Drivers: The Definitive Technology Mythos XTR-40 loudspeaker utilizes Definitive's patent-pending XTDD technology anodized aluminum dome drivers for extraordinary performance. Using state-of-the-art computer modeling and decades of speaker design experience, Definitive engineers eliminated every inch of wasted space, optimized every part, and maximized the moving surface area of a dynamic driver to shrink it down to a very compact dimension without giving up ultra high performance audio fidelity. The XTDD drivers provide dynamic punch, a wide frequency range, and broad dispersion that flat vibrating membrane panel-type speakers simply cannot match.

Pressure Coupled Design: To extend and deepen the bass response of such a thin speaker, the two 3.5" XTDD drivers are pressure coupled to two anodized aluminum dome bass radiators.

Enclosure Design

Ultra-Thin Aluminum Enclosure: The Definitive Technology Mythos XTR-40 features an ultra-thin (1.5" deep) aircraft-grade aluminum cabinet that fits today's flat-panel televisions perfectly. By specially shaping the enclosure and incorporating stiffing ribs and channels, Definitive made the space-efficient extruded aluminum enclosure ultra-rigid and resonance-free. The magnets of the XTDD drivers protrude through the rear wall of the enclosure to further minimize depth. A thermally conductive gasket seals the enclosure/magnet interface and transfers heat from the driver's rare-earth magnet to the enclosure, making the whole enclosure a giant heat dissipater.

Magnetic Grille: The Mythos XTR-40 LCR speaker features a black cloth magnetic grille which easily attaches and detaches from the speaker.


Speaker Terminals: The Mythos XTR-40 is equipped with a plug-in C-clamp speaker terminal to attach your receiver's speaker wire (up to 14 AWG).

Mounting Options

Applications: The Mythos XTR-40 can be used as left & right main, center, and surround speakers in your home theater audio system. The Mythos XTR-40 can be mounted on the wall vertically or horizontally as a left & right main speaker, center speaker, or surround speaker. It can also be placed on a tabletop horizontally.

Tabletop Placement: The Mythos XTR-40 can be placed horizontally on a table or shelf using the supplied feet-stabilizers. The feet-stabilizers screw into the 1/4"-20 threaded inserts on the back of the speaker's enclosure.

Note: The XTR-40 does not allow for vertical tabletop placement.

Wall Mounting: The Definitive Technology Mythos XTR-40 can be mounted directly to the wall using the two key-hole slots on the back of the enclosure and the included wall-mount bracket (mounting screws sold separately). The Mythos loudspeaker can be mounted on the wall horizontally or vertically. The speaker measures 1.5625" deep with the wall-mount bracket attached.

Note: A horizontal and vertical template is supplied to help with installation.

Our Product Research Team

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Customer Q&A

Looking for more? Check out the next model in this lineup.

Definitive Mythos XTR50

Definitive Technology Mythos XTR®-50 Wallspeaker


In Stock

$629.10 After $69.90 Outlet Savings

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Get the original XTR speaker

The Definitive Technology Mythos XTR®-50 Wallspeaker offers these features:

adds two more passive radiators to produce bass down to 92 Hz

measures 27" long, making it a better match for TVs 50" & up

comes with a glass stand for easy vertical tabletop placement