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Definitive Technology BPX

Single bipolar surround speaker

Item # 735BPX

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Our take on the Definitive Technology BPX

Definitive's bipolar surrounds aren't fussy about placement — they shine in a variety of room sizes and shapes. A pair of BPXs works well on your side walls for 5.1 systems, or on the side and rear walls for a 7.1 system. Each speaker comes with an easy-to-use mounting plate for on-wall installations. You can also place this speaker on a shelf or stand and enjoy equally great sound.

Enjoy rich, enveloping sound from Definitive's bipolar driver array

Definitive Technology's BPX surround speaker features many of the same high-quality materials as their larger, bipolar floor-standing models. Each speaker contains left- and right-firing driver arrays that radiate full-range sound in an omni-directional pattern — you'll really hear the difference as on-screen action shifts seamlessly from one side of the room to the other.

Bipolar design gives you a wide rear soundstage

Each driver array in the BPX consists of dual 5-1/4" woofers paired with a 1" dome tweeter, for robust, smoothly blended sound that won't get lost in larger rooms. This bipolar design creates a large, immersive soundfield, which is really effective for surround speakers.

speaker detail

Versatile placement options

Definitive's bipolar surrounds aren't fussy about placement — they shine in a variety of room sizes and shapes. A pair of BPXs works well on your side walls for 5.1 systems, or on the side and rear walls for a 7.1 system. Each speaker comes with an easy-to-use mounting plate for on-wall installations. You can also place this speaker on a shelf or stand and enjoy equally great sound.

Build a complete home theater system using perfectly matched Definitive Technology front and center speakers. The BPX surrounds pair well with Definitive's BP7002 and BP7004 floor-standing speakers, and the C/L/R2500 center speaker.

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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 aboutconditioning your speakers.

Product Highlights:

  • bipolar speaker technology
  • frequency response 38-30,000 Hz
  • sensitivity 90 dB
  • 8-ohm impedance
  • handles up to 350 watts
  • left array: dual 5-1/4" woofers and 1" pure aluminum dome tweeter
  • right array: dual 5-1/4" woofers and 1" pure aluminum dome tweeter
  • integrated wall-mounting plate
  • 5-way binding posts
  • piano-gloss black finish
  • 10"W x 17-3/4"H x 6-5/8"D
  • weight: 21 lbs. (each)
  • warranty: 5 years
  • Our 60-day money-back guarantee

What's in the Box:

  • Black full-range bipolar surround/satellite speaker
  • Metal bracket
  • 2 Mounting screws
  • Owner's Manual
  • Online Product Registration card

Hands-on research

Product Research

Overview: The Definitive Technology BPX Full-Range Bipolar Surround Speaker utilizes state-of-the-art components (high-definition bass/midrange drivers with butyl rubber surrounds, wide-dispersion pure aluminum dome tweeters with magnetic cooling fluid, complex Linkwitz-Riley crossover networks, and a solid monocoque cabinet with a diffraction-less grille/baffle interface) in order to achieve the most lifelike sound possible in your listening room. The BPX is a compact, high-quality bipolar (equal sound radiates both front and rear) speaker intended primarily for use as a rear or side surround speaker in a Dolby Pro Logic, DSP, DTS, or Dolby Digital surround sound system. In addition, the BPX can also be uses as a "front effects" speaker in multi-channel DSP systems or as a front main left and right speaker.

Driver Technology
Enclosure Design
Mounting Options

Driver Technology

Bipolar Design: The Definitive Technology BPX is a true bipolar speaker, containing two complete full-range speaker systems; one on each side of the cabinet. Definitive's Bipolar technology radiates sound from the front and the back of the speaker for more life-like sound and spacious imaging for every listener in the room. Bipolar technology combines the performance advantages of direct radiating (imaging, focus, localization, and specificity) and dipolar speakers (spacious, all-enveloping ambience) into one ideal speaker which is perfect for all multi-channel formats. The BPX tremendous dynamic range, as well as true high-definition sound quality, combined with its bipolar radiation pattern results in total immersion in the sound field.

High-Definition Die-Cast Basket Drivers: The BPX features four 5-1/4 inch high-definition cast-basket bass/midrange drivers for significant performance advantages in the areas of bass reproduction, lifelike midrange clarity and dynamic range. These sophisticated drivers incorporate deeply drawn mineral-filled polymer cones, combined with butyl rubber dust caps and surrounds, high temperature vented voice coils and massive magnet structures. This combination of features assures high definition, superb transient response, high efficiency, high power handling and extended linear response. In addition, the aerodynamically designed, non-resonant, cast-magnesium baskets minimize reflections of the sound radiating from the back of the cones and preserve structural and magnetic integrity.

Moving-Coil Pure Aluminum Dome Tweeters: The magnetic fluid-cooled moving-coil pure aluminum dome tweeters Definitive developed for the BPX are of a unique design that synergistically brings together the performance advantages of metal domes (greater clarity) and soft domes (smoother sound and better dampening) in one state-of-the-art tweeter design. The pure aluminum dome is specially annealed (to "relax" the crystal structure) and acoustically loaded by a precisely configured acoustic phase plug/lens (to assure perfectly controlled, absolutely linear movement). The tweeter's voice coil sits in ferro-magnetic colloidal fluid which serves to cool the voice coil for exceptional power handling and also damps the system for smoother response and sonic accuracy. In addition, the unique silk surround provides better dampening and wave termination. The audible benefits of all this highly advanced engineering include smooth extended high frequency response (beyond 30 kHz), greatly reduced distortion, improved transient response, notably higher definition, and crystal clear life-like clarity.

Voice-Matched: The BPX is a full-range, extremely linear, low-distortion speaker which is timbre-matched to blend perfectly with all Definitive BP and Studio Monitor series speakers as well as other high-quality speaker systems.

Enclosure Design

Non-Resonant/Low-Diffraction Cabinet: The monocoque cabinet of the Definitive Technology BPX is constructed of extremely thick, dense medite with foam damping pads and extensive internal bracing. This virtually eliminates cabinet vibrations and resonance which would otherwise interfere with the pure sound produced by Definitive's high-definition drivers.


Binding Posts: The BPX is equipped with a pair of gold-plated, 5-way binding posts to attach your receiver's speaker wire.

Mounting Options

Mounting: The Definitive Technology bipolar surround speaker is designed for easy and unobtrusive placement in your room. It can be mounted to a wall with the supplied mounting-plate or placed on a shelf or stand for the ultimate in surround sound realism.

Applications: The Definitive Technology BPX speaker can be used as a rear or side surround speaker, front effect speaker, or as a front main speaker.

  • Rear or Side Surround: The BPX is designed to be extremely flexible in terms of their placement when used as surround speakers. Positioning is non-critical; unlike dipolar surrounds, which are limited by their specific sidewall placement requirements, the Definitive Technology bipolar speaker may be located on the sides or rear of the room (or both as in 6.1 and 7.1 channel installations) or on the ceiling. They may be mounted on the rear wall (with their front drivers shooting towards each other and their rear drivers shooting toward the side walls) with excellent results.
  • Front Effects: The BPX is ideal for use a front effect speakers in DSP installations. The speaker should be placed on the front wall with the wire terminals against the wall and the speaker separated by approximately two-thirds of the front wall. Placement above ear level is also recommended.
  • Front Main: The BPX can also be used a front main speaker due to its superb performance characteristics. In this configuration, two BPX speakers should normally be placed about 6-8 feet apart, approximately at ear level, facing toward the listening position.

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