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Definitive Technology SR-8040BP

Bipolar surround speaker

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Item #: 735SR8040

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23 Reviews | 2 questions - 5 answers


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Bipolar design creates wraparound sound

Definitive Technology SR-8040-BP

Experience that "I'm there" feeling on your next movie night with Definitive's SR-8040BP bipolar surround speaker. It 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. Part of Definitive's Bipolar Series, it combines advanced driver design and sturdy construction to give you exceptional detail and presence with ambient effects and multichannel music.

High-tech drivers for exceptionally detailed sound

Each driver array in the SR-8040BP has a 3-1/2" midrange paired with a 1" dome tweeter, for perfectly blended highs and mids. This bipolar design creates a big, immersive soundfield, which is really effective for surround speakers. Each pure aluminum dome tweeter has a silk surround, allowing it to reveal delicate, low-level ambient details in soundtracks. And thanks to Definitive's Balanced Double Surround System (BDSS) drivers, your movie special effects and multichannel music will sound clear and detailed. These mid/woofers disperse the sound over a wide area in your room so that even viewers sitting off-axis hear smooth, engaging sound.

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 SR-8040BPs works well on your side walls for 5.1 systems, or on the side and rear walls for a 7.1 system. Each speaker has a keyhole slot for on-wall installations. You can also place this speaker on a shelf or stand and get great results.

Build a complete Definitive home theater system by adding perfectly matched bipole towers (see the BP-8020ST, BP-8040ST, BP-8060ST, and BP-8080ST) and a center channel (see the CS-8040HD, CS-8060HD, and CS-8080HD).

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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:

  • Linear Response Waveguide™ for wide dispersion and smoother sound for listeners sitting off axis
  • Balanced Dual Surround System (BDSS) driver technology places rubber surrounds on both the outer and inner edges of each speaker cone for improved clarity
  • frequency response 50-30,000 Hz
  • sensitivity 92 dB
  • 8-ohm impedance
  • handles up to 150 watts
  • left array: 3-1/2" mid/woofer and a 1" aluminum dome tweeter
  • right array: 3-1/2" mid/woofer and a 1" aluminum dome tweeter
  • one set of 5-way binding posts
  • high-gloss black finish on top and bottom caps with cloth grille-wrapped enclosure
  • 7-7/8"W x 9-5/8"H x 5-3/8"D
  • weight: 8 lbs.
  • warranty: 5 years
  • Our 60-day money-back guarantee

Definitive Technology SR-8040BP Reviews

Average Customer Review:

23 Reviews

Perfect Surrounds

Written by: Chaz BC from Big Canoe, GA on January 21, 2016

Crutchfield Customer Review (What's this?)

Excellent speakers. Paired with 8060 towers and 8060 center.

Pros: Price (on sale) Nice Finish Big Sound

Cons: None so far


Written by: Bill B. from Florida on December 29, 2015

Crutchfield Customer Review (What's this?)

These surround speakers are excellent. They complete my Def Tech system of the 8020 towers and the pro1000 . The whole system is now excellent. I only gave them a four because I'm sure the next step up Def Tech surrounds probably sound better with lower bass. But they are very good, if not a little expensive for a surround speaker, but you get what you pay for. I am pleased with them.

Pros: Good sound, good looks.

Cons: Price

Very Nice

Written by: Mark from Charlotte, NC on December 8, 2015

Crutchfield Customer Review (What's this?)

The quaility of these speakers are awesome! You can't go wrong with there.

Pros: Sound and construction.

Cons: None.


Written by: Jwilly from Colorado on December 5, 2015

Crutchfield Customer Review (What's this?)

This was a replacement due to a puppy incident. Excellent sound. Great size for a speaker stand or mounting on the wall

Pros: Excellent sound. Great size for a speaker stand or mounting on the wall

Cons: Price. Unless on sale

Definitive Technology SR-8040BP

Written by: Anonymous from Texas on November 27, 2015

Crutchfield Customer Review (What's this?)

Very sleek look. Easy to install



Awesome Sound

Written by: John K. from Wallington, NJ on November 16, 2015

Crutchfield Customer Review (What's this?)

Bought these to join my Definitive Bipolar 8060 ST front and center speakers. As expected they sound amazing, the sound fills the room and I love the sleek black color. Highly recommended.

Pros: Excellent sound, great build quality, nice black finish.

Cons: None.

Solid surrounds

Written by: David from Utah on January 23, 2015

Crutchfield Customer Review (What's this?)

Rock solid build surround speakers. Heavy for there size. Great sounding. If you want to use banana plugs then you'll have to have a single gang box behind the speaker and run the speaker wire through the wall. There is not enough recess on the back of the speaker to fit banana plugs against a flat wall. Binding posts work just fine. I used a 40lb drywall anchor and a screw to hold the speaker and it is plenty strong.

Pros: Solid construction. Good sound

Cons: None really.

Def Tech always tops.

Written by: Chris from NC from Fuquay, NC on January 23, 2015

Crutchfield Customer Review (What's this?)

Excellent build look and sound. I love all my Def Tech speakers... always top quality.

Pros: Quality and sound that is unmatched.


Big gil 52

Written by: Percy from Baltimore,Md on August 10, 2014

Sinsational,the 8040,s are some of the best surrounds ,I have listened to for the money,can't go wrong adding these beauties to your theater system.



Def Tech SR-8040BP BIG SOUND/small package

Written by: The Amazin' Zoltar from Warwick, NY on March 26, 2014

Crutchfield Customer Review (What's this?)

I needed to replace a pair of blown M5 Polk speakers that had been used for 20+years as rear surrounds in a 5x1 system. The old Denon high end receiver has a legitimate 140RMS X5 power rating. I did not want a big speaker and wanted as full of a sound spectrum as i could get. The specs of these bi-polar beauties were within the realm of what i was looking for. I took a chance, spent the money, and am happy with the purchase. One rear screw slot mounts these small, all black speaker to your wall/mounting plate. Used as surrounds, they were definitely just what the doctor ordered-and are better performers than my original M5 Polks were. I think you'd be happy hearing the ocean, birds, crowd noise, and ambient gunshots that these bad boys can produce with aplomb!

Pros: Great small surround speakers that hide unobtrusivly in any room. Easy to install with one screw. Big sound for average home theater room dynamics.

Cons: Not inexpensive.


Written by: Gary from Rogers, AR on February 6, 2014

Crutchfield Customer Review (What's this?)

I got these surrounds with the package deal from Def Tech when you bought 2 8060 towers, and originally i used the towers with my ProMonitor 800 speakers as surrounds. I noticed pretty quick the 800s were outmatched by the 8060 towers under heavy action in movies. Once I finally got these installed I was amazed by the difference with these compared to the 800s. I still believe the 800s are great speakers, but these produce way more sound.. The sound quality is exactly what you'd expect from Def Tech.

Pros: Great surround speakers..

Cons: Not really a con, but be sure to note these are 8lbs.. I missed that when i purchased these, and had to rework my speaker mounts. Not a huge deal, but just something to keep in mind. A couple Hangman Double Headed Bear Claw screws, and i had them up on the wall..

Great Side Or Rear Speakers

Written by: CarolW from Keller, TX on January 28, 2014

Crutchfield Customer Review (What's this?)

These are great speakers when used for side speakers or rear speakers. They just create a beautiful look with the Definitive Technology center channel and tower speakers. I could not be happier with this set. Top quality equipment!!

Pros: Quality sound, looks.

Cons: None.

great product

Written by: tom3jr from Waldwick, NJ on January 6, 2014

Crutchfield Customer Review (What's this?)

These speakers completed my package of Definitive Technology system.




Written by: Chris from Fort Worth on December 7, 2013

Crutchfield Customer Review (What's this?)

Excellent sound. Crisp, clear, good bass. I'm using these speakers as my side L & R surround speakers in a 7.2 setup. Pretty good sizing living room area, too. 16' x 30', with 10' ceilings. They do what they're supposed to do. From Korn & Metallica to Christmas music to Dark Knight Rises, they really do their job. Would recommend to anyone if they're willing to spend the money.

Pros: Look great. Sound great.

Cons: None.


Written by: Anonymous from hillsdale. MI on November 13, 2013

Crutchfield Customer Review (What's this?)

Excellent match to the 8060's I purchased.

Pros: Truly the perfectly matched surrounds for a seamless sound from front to back, using 8060's across the front.

Cons: None

Greate rears

Written by: Mrbill from los angeles on March 31, 2013

Crutchfield Customer Review (What's this?)

Love my speakers


Cons: none

Definitive Technology SR-8040BP

Written by: SW from rockford, il on March 29, 2013

Crutchfield Customer Review (What's this?)

Great sound quality for the price, works well as the single rear in a 6.1 setup.

Pros: sound quality

Cons: none

Worth every penny!

Written by: Dave from Discovery Bay, CA on March 26, 2013

Crutchfield Customer Review (What's this?)

I purchased these 8060 towers, the 8060 center and the 8040 surrounds. The 8040 surrounds are amazing. I wasn't too sure how the black speakers were going to look on the walls since our old speakers were small, white infinity minuettes. Actually it was my wife that was really concerned, but the 8040's look great, and the best part is, she agrees! They sound so much better than my old surrounds and they really have a classy, sexy look to them. My old surround speakers sounded good, but these sound amazing!

Pros: Great sound and presence for a surround speaker!

Cons: None!!!

Big sound from small speaker

Written by: dale G from St. Louis on February 15, 2013

Crutchfield Customer Review (What's this?)

Great sound from a little speaker. Solid build and finish.

Pros: solid build and great sound

Cons: speaker only has a keyhole slot mounting option.

Clean and Clear

Written by: Bid Daddy from Toledo OH on February 10, 2013

Crutchfield Customer Review (What's this?)

I forgot to review these speakers earlier. Bought the Def Tech package. These speakers do exactly what they are intended for. clear surround sound. they add spaciousness and even sound dispersion. this speaker set ROCKS. Movies are great and tunes sound fantastic. Will eventually move them to the sides to replace a pair of 1000 monitors and purchase the 8080's for the rear. You will not go wrong purchasing these speakers. They look awesome hanging on the walls.

Pros: Very nice sound quality. Easy to hang and connect. Looks sweet.

Cons: When wall mounting can not use plugs. no big deal though

8040 vs 8080

Written by: Mistawankaz from Syracuse, NY on August 23, 2012

Crutchfield Customer Review (What's this?)

First off. These were mounted to my wall easily and effortlessly. So I really have no idea how/why a previous review stated otherwise.

My review is just a comparison of 8040 to 8080. The 8040 are the best backup speakers I could of asked for. I have the deftech 8080st and 8080 CR mid. I went with 8040 rears to see if it would really matter for the sound stage (in comparison to the 8080SR). The sound quality in a 13 x 24 foot room is just incredible. These "little" guys can really hammer out lows, and accent the ST's/CR amazing sound quality. This was of course only a 5.1 setup. 80's up front and the SR40's in back.

After all this good news (and incredible sound quality) I finally decided to go from 5.1 to 7.1 (I wanted to see if a sale for the 80 or 40 SR would happen) I got the 8080SR for my rears and tossed my older 8040's for my right and left middle. For the extra $ per speaker I paid. The 8080's are worth it, lower lows are totally noticeable. But in nearly every aspect the 40's keep up surprisingly well. I would have no worry in telling anyone to get the 8040 SR over the 8080 everyday. Unless they truthfully feel the smallish boost in bass/loudness will bug them. The fact of the matter is, because they are rear/surrounds. They just never get pushed to the max, so getting a bigger all around rear/surround speaker could be $ down the drain.

For anyone who doesn't understand. Get the 8040's unless you think you will notice the small boost from the 8080's

Pros: Best rear speakers I have ever had that are under 500$ per speaker. Generically easy setup/mounting to wall. Loud and clear. Look very stunning on the wall. Dual direction makes for the sound stage to fill the room easily no matter placement. For what they are the price is astounding.

Cons: None, but deftech should consider a price change (or calling this one the 8060 and inventing the 8040 as a even smaller speaker). They are worth the money, but the price for a STBP setup rears seem almost too much. If they offered some for 150-250 and 350. I could better recommend what ones to get to everyone. But right now saving the $ (per pair) by going with the SR8040 over the SR8080 is a no brainer. So I always recommend the smaller pair.

Amazing Surrounds

Written by: Chad S from Raleigh, NC on January 21, 2012

Crutchfield Customer Review (What's this?)

Order these Def Tech surrounds with the whole BP system, needless to say, they sound amazing. They manage to put out a very enveloping sound field. Mounting was pretty easy, just throw and screw in to a stud and throw the speaker on it, done.

Pros: Clarity Coverage Looks

Cons: Need to run in wall wiring if you plan on using banana plugs

Missing Wall-mount Hardware

Written by: Bob from Hurst, TX on October 30, 2010

Crutchfield Customer Review (What's this?)

These speakers sound very good, but be aware that they do not come with all the hardware necessary to mount them on a wall. This isn't really spelled out in the information on the speakers; in fact, they are advertised as coming with "an easy-to-use mounting plate for on-wall installations." The mounting plate is all they come with. If you want to find the rest of the hardware necessary for wall mounting, good luck. It seemed reasonable to me that this price would include all the hardware necessary for wall mounting.

[Editor's Note: We apologize for any inconvenience. We have edited our web presentation to avoid similar confusion in the future.]



Hands-on research

What's in the box?

Download owner's manual

  • One black full-range bipolar surround speaker
  • 2 Grilles
  • Owner's manual
  • Online product registration information

Scratch & Dent items may be missing non-essential accessories. In some cases the manufacturer's accessories have been replaced with generic equivalents.

Product Research


Bipolar Design: The Definitive Technology SR-8040BP is a bipolar surround speaker, containing two full-range woofer and tweeter arrays. The speaker cabinet has three sides, with the driver arrays firing in phase approximately 100° apart to flood the area with sound (the third side mounts against the wall). Dispersing the surround channel's sound evenly over a broad area of the room creates an enveloping movie experience.

Drivers: The two woofers used in the SR-8040BP are 3-1/2" second generation BDSS (Balanced Double Surround System) drivers. BDSS is Definitive's patented technology that supports the speaker cone at both the inner and outer edges allowing longer and more linear excursion for greater clarity and detail. The new Linear Response Waveguide (patent pending) smoothes off-axis frequency response and disperses sound over a wide area. The two tweeters are pure aluminum domes, heat-treated to relax the crystal structure, then coated with a ceramic to produce extended highs. The Linkwitz-Riley crossover networks maintain a smooth output around the crossover frequency.

Voice-Matched: The SR-8040BP is a full-range low-distortion speaker which is timbre-matched to blend perfectly with all of Definitive's BP series speakers.

Binding Posts: The speaker terminals are gold-plated, 5-way binding posts and will accommodate spade connectors, single or dual banana plugs, pin connectors, and bare wire up to 10 gauge.

Mounting: The SR-8040BP is designed for easy placement; it has a keyhole slot for wall mounting, or it can be placed on a shelf or stand. It's designed as a surround speaker (surround or surround back channels), but can also be used for front effects channels in Audyssey DSX, Dolby Pro Logic IIz, or Yamaha DSP 3D (with presence speakers) systems.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Customer Q&A

Crutchfield asked  
Why did you buy this?

Reputation, value and overall system balance. [ Jeffrey  Jan 26, 2016 ]
Bi-polar design matched with DefTech's 8060ST's for use as surround channel speakers [ Jacob  Jan 16, 2016 ]
surrounds [ DAVID  Jan 14, 2016 ]
It goes with my existing speakers [ Brian  Jan 06, 2016 ]
surrround speakers with good reviews and affordable. [ calvin  Jan 01, 2016 ]
I already bought the predecessors to these speakers and have not only loved the neutrality and quality of the sound, but have enjoyed their flexibility in placement. So I wanted to try a pair with the newer drivers and ability to be used with higher powered amplification. Hope to use as BOTH surround AND front L/R ! [ Bradford  Dec 31, 2015 ]
Nice sale price [ Keith  Dec 29, 2015 ]
specs and size. very good reviews. [ jerzy  Dec 21, 2015 ]
Review's [ BRYON  Dec 19, 2015 ]
These Definitive Technology speakers provide the capabilities, both bipolar and power, that I was looking for in rear surround speakers. The price was fantastic. The tech support, Larry, was really helpful. [ Roger  Dec 10, 2015 ]
These are best bang for your buck. They are surprisingly heavier than anticipated, but that tells me I'm not getting junk. The sound is excellent, the style and finish are very sharp as well; just very impressed with DT. Fair pricing for a great product! [ Andrew  Dec 04, 2015 ]

2 questions already asked

I'm not sure about the speaker stands but I installed mine onto a studded sheet rocked wall and it's fine. [ PASQUALE  Nov 12, 2014 ]
don't know, mounting is from the upper back. hung mine from the wall. great sounding speaker [ KEVIN  Nov 11, 2014 ]
Hi John, Answer to your question is no, because of the triangular stand. I called a custom installer and he put it to the walls. Enjoy your shopping. But the speaker quality is great. Thanks [ HAR  Nov 11, 2014 ]
I have 4 of these as side and rear surround speakers in a 7.1 system. I too have BP 8040ST front tower speakers and an 8040 center as well. The 4 SR 8040's are slightly angled downward and mounted about 12 inches from the ceiling (room has 8 1/2' ceiling and is 17' w x 34' long). They work great and provide "theater-like" surround sound. Great product from my experience and Crutchfield advisors are always very helpful. [ RICHARD D  Jun 17, 2014 ]
The SR-8040 is factory designed for vertical wall mount only. [ DANIEL  Jun 17, 2014 ]

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

Definitive SR-8080BP

Definitive Technology SR-8080BP


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Bigger woofers for deeper sound

The Definitive Technology SR-8080BP offers these features:

uses dual 4-1/2" woofers for bass down to 40 Hz

handles up to 200 watts