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Polk Audio FXi A4

Dipole/bipole surround speakers (Black)

26 Reviews | 4 questions - 14 answers

Item # 107FXIA4B

In Stock

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Was: $399.99

Special Purchase: -$150.00

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Our take on the Polk Audio FXi A4

Add the Polk FXi A4 surround speakers to your home theater system and enjoy dramatic rear-channel sound effects with your favorite movies. These cleverly designed speakers feature two tweeters aimed 45° from each other, for an ideal mix of direct and indirect sound.

Add the Polk FXi A4 surround speakers to your home theater system and enjoy dramatic rear-channel sound effects with your favorite movies. These cleverly designed speakers feature two tweeters aimed 45° from each other, for an ideal mix of direct and indirect sound.

Dipole/bipole operation for flexible placement
A dipole/bipole switch lets you position the FXi A4s on the rear or side walls of your home theater room — you'll get great results either way. If you place them behind your listening postion, set them to bipole mode for distinct, directional sound. Or set them to dipole mode for side placement, and they'll create a more diffuse soundfield for convincing wraparound effects.

A high-tech approach to accurate sound
Polk carefully designed the drivers using laser testing to help identify and eliminate resonance points. The acoustically inert MDF cabinets fight internal vibrations that can compromise performance. It all adds up to enveloping surround sound that fully immerses you in the movie action.

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Product Highlights:

  • bass-reflex (ported) design
  • frequency response 60-26,000 Hz (-3dB)
  • recommended amplifier power: 20-125 watts
  • two 1" silk/polymer dome tweeters
  • 5-1/4" Dynamic Balance® polymer composite woofer
  • 8-ohm impedance
  • sensitivity 88 dB
  • dipole/bipole switch
  • keyhole slot for easy wall-mounting
  • 5-way binding post terminals
  • voice-matched to Polk's RTi tower and bookshelf speakers and CSi center channel speakers
  • 11-5/16"W x 12-1/16"H x 7-13/16"D
  • warranty: 5 years
  • Our 60-day money-back guarantee
Priced per pair

    What's in the Box:

    • 1 Black left surround speaker
    • 1 Black right surround speaker
    • 2 Self-tapping screws
    • 8 Self-adhesive rubber feet
    • Owner's Manual (English/French/Spanish)
    • Template
    • Online registration sheet
    • Polk Audio product brochure

    Really sounds nice. I am happy with my purchase.

    Anonymous, Frisco, TX


    Polk Audio FXi A4 Reviews

    Average Customer Review(s):

    (26 Reviews)

    Polk Audio FXi A4

    Anonymous from Frisco, TX on 4/15/2018

    Crutchfield Customer Review (What's this?)

    Really sounds nice. I am happy with my purchase.



    perfect for Atmos

    Ted from Houston, TX on 2/20/2018

    Crutchfield Customer Review (What's this?)

    replaced a pair of polk bookshelf speakers for side surrounds. They were within 4 ft of the two side by side seats, respectively, because of small room and I could easily localize sounds as a point source from the bookcase speakers. The FXi A4 surround speakers in Bi-pole setting give lots of sound but it is not localized to a point source on the wall. Much better.

    Pros: diffuse sound

    Cons: none

    Polk Audio FXi A4

    Michael from Indianapolis, IN on 2/6/2018

    Crutchfield Customer Review (What's this?)

    I really like these. I am using these on my back wall in bipole mode and they are a huge improvement than what I previously had. My only issues are the instructions are a little confusing on placement but Polk's customer service was fantastic and got back to me quickly with an answer. My other issue is that you cant use banana plugs if you hang them on the wall, there isnt enough clearance.

    Pros: Clean Design, good sound.

    Cons: Confusing instructions, not enough clearance for banana plugs on wall

    Rome filling sound

    Terry Hunter from Maple Grove, MN on 1/28/2018

    Crutchfield Customer Review (What's this?)

    One wait to feel a room with sound It works really well for me With my Sony STR550And to polk audio subwoofers

    Pros: For me everything about it

    Cons: After hooking it up and listening to the sound straight out of the box I had no complaints

    Polk Audio FXi A4

    Anonymous from Madison Hts, MI on 12/24/2017

    Crutchfield Customer Review (What's this?)

    Great thundering sound. Step up from our other speakers.



    Great sound

    Scott from Tacoma, WA on 12/15/2017

    Crutchfield Customer Review (What's this?)

    Great sound from these polk audio surround speakers, not to mention that they look good also, perfect for wall mount or on stands.

    Pros: Sound great, looks stylish

    Cons: None

    Polk Audio FXi A4

    JD from Cherryville, NC on 10/13/2017

    Crutchfield Customer Review (What's this?)

    I can't say enough good things about Polk speakers, I have owned some form of Polk for over 25 years now and I keep going back to them. Reason why is they are affordable and they sound amazing good quality built speakers for the money. These hold up to the Polk name for me they are great good quality surround sound. I always buy the higher end Polks so I am not sure about the cheaper entry level speakers but these as well as my other floor standing, center and subs, all meet my expectations. And as always Crutchfield is an amazing company that I have been doing business with for over 30 years.

    Pros: clarity, loudness and function great as surround rear speakers dividing the sound as should be.

    Cons: None

    Good value and sound

    Jake from Cincinnati, OH on 10/13/2017

    Crutchfield Customer Review (What's this?)

    Sound good. Smooth and not distracting. Good size. Easy install 3rd Polk SS speaker set. Good value.

    Pros: Value, sound, size

    Cons: None

    Excellent surround sound in a less than perfect home theater room

    Mike from Waterbury, VT on 10/1/2017

    Crutchfield Customer Review (What's this?)

    I was using a set of book shelf speakers for my surround speakers and wanted to improve the overall theater sound quality in my home theater room. The room is not perfect, with one side longer than the other, so was concerned that even a quality dipole speaker would not be sufficient. However, when I hooked up the FXi A4's, they performed fantastically! The quality and surround sound is what I was looking for. My home theater is now complete!

    Pros: Awesome sound at a budget price

    Cons: none so far

    Polk Audio FXiA4 Black Pair

    Anonymous from Queen Creek, AZ on 8/27/2017

    Crutchfield Customer Review (What's this?)

    Replaced a basic pair of Paradigms. Using Sonus Faber Venere 2.5 for my front and centers with Paradigm DSP 3200 sub and Marantz SR-7007 receiver in a 5.1 setup. I bi-amp the right and left speakers. These Polks are on stands on either side of a sectional sofa. Instant huge improvement! And for the price, unbeatable! Allowed me to budget to obtain the beautiful and awesome Sonus Faber speakers and the Paradigm sub on the same purchase. No regrets.

    Pros: Great performance and price.

    Cons: None.

    Makes sense to match CSi A4 center channel speaker

    Kevin from Salem, NH on 8/9/2017

    Crutchfield Customer Review (What's this?)

    I was running all Polk speakers and an old pair of Cambridge Soundworks surround speakers. I finally completed my set with these rear surrounds. They sound awesome with the voice matched Polk CSi A4 center channel. Big speakers as is. I can't imagine going up to the next size Polk rear surrounds. Very happy with purchase!

    Pros: Great sound

    Cons: Very large. I had a hard time making them work on my original speaker stands.

    Polk Audio FXi A4

    Anonymous from Bristow, VA on 6/12/2017

    Crutchfield Customer Review (What's this?)

    My viewing area is in a small space and the design of these speakers gives 7.1 sound from a 5.1 system. Once again the quality I have come to expect from polk.



    Great Value

    Barry from Mandeville, LA on 8/6/2016

    Crutchfield Customer Review (What's this?)

    Sounds great well constructed




    Mark from Maui on 6/3/2016

    Crutchfield Customer Review (What's this?)

    Great reflection and fills the room with all the small nuances needed in a satellite speaker. Handles the power with depth and clarity.

    Pros: Easy to mount on Wall and the clarity and space filling in a surround system is remarkable!

    Cons: Not sure I can find any.

    Polk Audio FXi A4 surrounds

    Pat M from Virginia on 1/5/2016

    Bryan L. of Crutchfield has provided excellent advice and support in selecting these speakers to accompany the Onkyo receiver he recommended. Technical support was superb in assisting installation via phone. The speakers are wall-mounted behind the listener (not on the side wall) and once balanced via the receiver's microphone have made a terrific addition to the 5.1 system. They definitely improve the sound with ambient images without overwhelming the main speakers (B+W 685's). The room is relatively small (15x15), and the power is more than adequate. Be sure to set the bi/di switch on the speaker's back and carefully put them on the correct side (R or L). Great design seems to me to provide a better listening field than speakers firing straight out. Sound fidelity is excellent. Patient, professional and knowledgeable salesperson in Bryan. Thanks.

    Pros: Excellent design. Quality sound. Mirror imaged speakers. Mounting bracket on each speaker.

    Cons: None.

    upgrading surrond speakers

    Joshua from Indiana on 3/28/2015

    Crutchfield Customer Review (What's this?)

    Was looking to upgrade Polk 5.1 system surround speakers (had RM7600s). stuck with Polk and they do no disappoint. These surrounds perform very well. Great for movies and even when playing music they have been a great upgrade.

    Pros: The Dipole/bipole switch is the feature that sold me on these speakers.

    Cons: Could not use the Banana plugs since I mounted them directly onto the wall. (I have straight plugs, have not tried a different version)

    customer review

    steven from South Carolina on 1/10/2015

    Crutchfield Customer Review (What's this?)

    great product and sound. the bracket design is not as robust for hanging the speaker on a wall as I would have anticipated. while the bracket is stamped steel, it is attached to the speaker with only one, one inch wood screw. two would have been better, four best.



    perfect match

    bear from ocala,fl. on 8/13/2014

    Crutchfield Customer Review (What's this?)

    i was looking to upgrade from a borroewd pair of mb quarts and exhausted every review of every affordable rear channel speaker on the planet. (gotta make sure i make the right decision) since i don't have money to throw around i narrowed it down to 2. my system consist of a yamaha rxv 477 5.1 receiver. a pair of polk monitor series 2 70's and the mb quarts for the rears. i don't use a center channel speaker because my fronts are only 6 ft. apart. i just make the necessary adjustments on my receiver and no dialogue is lost. Anyway to match my fronts my choices were polk fxi a4 or the a6. I almost went for the a6's because the the drivers would of matched my monitors (as far as speaker size) but after reading the reviews and considering the size of my listening room 13 x 18 i went with the a4's. So when they arrived i didn't waste any time hooking them up. i have to say that these speakers took my system to a whone new levil. the a4's are a PURFECT match for my setup. I have watched Gladiator, Command and Conquer, Matrix reloaded, Sherlock Holmes game of shadows and Titanic. thats just in the last 24 hours. need i say more. polk makes a great product for the budget minded without comprimising on quality. Cooper a Crutchfield was great. no pressure sales is hard to find these days. they just answer youf questions and promply ship your stuff. .So if your in the market for rear surround speakers take a look at the polk fxi a4's. they are very clean and accurate and deliver.

    Pros: clean, accurate sound, great cabinet finish. great for movies or music

    Cons: i didn't purchase them sooner

    Polk Audio FXi A4

    Dee from Alabama on 1/5/2014

    Crutchfield Customer Review (What's this?)

    Bought as a gift for the hubby. He loves them. Truly enhances the surround system.



    Polk Audio FXi A4

    JohnB from San Jose, Ca on 1/5/2014

    Crutchfield Customer Review (What's this?)

    Rounds out my speaker upgrade, two Polk Audio TSx550T for the front, Polk Audio TSx250C center and these two for the rear. Great surround in rear, does not appear to be focused. Overall very satisfied with the performance thus far

    Pros: Great sound, nice appearance

    Cons: None


    marlin from orange,nj on 1/2/2014

    Crutchfield Customer Review (What's this?)

    glad with the deal from Crutchfield.... professional sound in my living room... afordabble...

    Pros: quality.

    Cons: none


    Ted from Odessa, Tx on 11/21/2013

    Crutchfield Customer Review (What's this?)

    The speakers are a decent size. I was watching a moving and i will admit i got scared. The sound that these speakers produce is impressive. It caught me off guard and made me jump. They integrate well with the rest of my polk speakers. This is a good buy.

    Pros: Price, sound, easy to mount

    Cons: I wish it had another driver on the other side.

    Polk fx

    Randy from Douglasville, GA. on 5/6/2013

    Crutchfield Customer Review (What's this?)

    Fast delivery, look great on the wall, sounds great.

    Pros: They go well with the Polk towers, great sound. Polk speakers like power and these can handle it.

    Cons: They do not come in cherry.

    well balanced sound and a great price point

    Don,S from North Greenbush,NY on 2/27/2011

    Crutchfield Customer Review (What's this?)

    What a great sound from these speakers smoothe and clear as a bell strong sturdy and not too heavy,and come with options also.Use as rear's you can bipole with the flip of a switch or surrounds and dipole them they sound fantastic. I was a little heasitant at first reading about them,now I would highly reccomend them at this price point. We love um



    Happy with My Choice

    Brian from NW, Ohio on 10/20/2010

    Crutchfield Customer Review (What's this?)

    As I was building my component HT system, when I got to choosing the rear/surrounds I was between the FXi A4's and A6's. With size of the speakers and the size of my living room (17x15) being a big consideration, I decided to try the A4's and have not been disappointed. I've never heard the A6's but can't imagine they can sound too much better. As another review stated these A4's sonically blend very well with the rest of my system (my other speakers include a pair of Polk A7 towers and for a sub I have a Klipsch RPW-10). My receiver is giving these speakers 110 watts per channel over a 50ft total (each) length of Original Monster Cable and they sound great. I have mine placed on the wall in the back of the room set to the bipole mode. There certainly is a bit of a noticeable difference between the bipole and dipole modes (dipole being more scattered immersing sound if placed on the side walls). They sound great for movies but I use my system alot for listening to music using one of my receiver's all channel stereo modes and these A4's do very well. These do not disappoint.



    Great surround speaker

    Steve from Las Vegas, NV on 2/21/2009

    Crutchfield Customer Review (What's this?)

    This speaker performs very well and blends in perfectly with my other Polk speakers. Set on the dipole setting they provide immersive sound without the ability to localize the speaker. One thing to be careful about is that the speakers are not identical. One speaker is labeled for right surround and the other for left.




    Hands-on research

    Product Research

    Driver Technology
    Enclosure Design
    Mounting Options

    Driver Technology

    Dynamic Balance: Dynamic Balance is a proprietary Polk Audio technology using laser imaging to determine what combination of speaker materials create the least amount of resonance. Eliminating resonance in speakers results in a wide, smooth response and low distortion.

    Polymer Composite Woofers: Each speaker features a 5.25" polymer composite woofer for smooth wide-range response with low distortion. For high performance durability, each woofer uses a butyl rubber surround.

    Silk/Polymer Tweeters: Each speaker has dual 1" silk/polymer dome tweeters that provide clear, detailed highs and spacious surround effects. Each tweeter uses a heat sink on the Neodymium magnet for superior heat dissipation, power handling and reliability.

    Frequency Response: The overall frequency response is 50Hz-27kHz and the -3dB frequency response is 60-26kHz.

    Enclosure Design

    Enclosure: Each enclosure has a triangular shape with the speaker faces angled at 45 degrees. One face has a tweeter and a woofer, while the other face has a tweeter and port tube opening. A switch for selecting Dipole or Bipole operation is located on the rear of the speaker above the speaker's 5-way binding post speaker terminals. One of the speakers is specifically designed for the "left" channel and the other for the "right" channel.

    Acoustically Inert Cabinets: Each speaker cabinet features all-MDF construction with internal bracings that virtually eliminate sound-muddying resonance. The speakers are finished in either a black or white laminate finish.

    Anti-Diffraction Grilles: The floating anti-diffraction grilles minimize grille diffraction for spacious, 3-dimensional imaging.

    Port: On the side with only a tweeter, there is a single port tube opening for increased and extended bass response.


    5-Way Binding Posts: The gold-plated 5-way binding posts will accept bare wire, pin connectors, spade connectors, banana plugs, and dual banana plugs.

    Mounting Options

    Dipole/Bipole Switch: There is a switch that allows each speaker to be used as a Dipole (out of phase) or Bipole (in phase) speaker. If you're mounting the speakers on the side walls in line with your listening position, the dipole mode will create a diffuse, ambient soundfield. If you're placing them behind your position, the bipole mode fires the drivers in phase to flood your room with surround sound. When used with a Dolby Digital system, the surround speaker setting should be set to small.

    Wall Mounting: The bracket on the back of each speaker has two keyhole slots, allowing the speaker to be mounted on the wall using the supplied 2-1/2" wood screws.

    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.

    Q & A

    Customer Q&A

    Crutchfield asked  
    Why did you buy this?

    I wanted Surround Speakers that offer a solid dispersion and would compliment my MartinLogan XLM's for LCR, but without the Motion FX price tag. [ RICHIE  Jan 31, 2018 ]
    I am unable at this time to go to a 7.1 setup so I am taking a chance on these. Reviews were good on Youtube and Crutchfield so when they went on sale I figured it was time. [ Michael  Jan 24, 2018 ]
    To enjoy full background sound [ Terry  Jan 13, 2018 ]
    Upgrading the surround speakers in my Polk Audio system [ stickywicked447  Jan 10, 2018 ]
    recommended by polk audio to match the RTia3 [ David  Dec 04, 2017 ]
    Polk makes good audio equipment. $150 savings on these speakers is a great deal !! [ John  Dec 01, 2017 ]
    Looking for a good surround speaker and Polk's reputation is excellent to say the least Reading through the reviews I didn't see any negative feedback at all [ Chad  Nov 26, 2017 ]
    On sale, good manufacturer, upgrade for rear channel sound [ Jeremy  Oct 17, 2017 ]
    Polk Audio Rocks [ ERIC  Oct 12, 2017 ]
    Quality Polk products [ Jeffrey  Sep 17, 2017 ]
    On-Line Reviews and Feedback from customers;. Sale Price. [ Mike  Sep 17, 2017 ]
    Cost and quality. [ L  Jul 29, 2017 ]
    From reviews and should work good for my surrounds and back speaker [ Keith  May 09, 2016 ]
    To match and compliment my existing Polk Audio gear. (3) 265rt's (L-C-R), (2) 255crt's in ceiling (Atmos) and (2) PSW505 subwoofers, for a complete 5.2.2 Home Theatre setup! [ Greg  Apr 10, 2016 ]
    Upgraded receiver to 7.2 from a of speakers are 10 year old Polk and wanted to maintain the same quality that I have been satisfied with for a decade [ JOE  Mar 22, 2016 ]
    Good reviews, and matches/compliments the RTI A9's and CSI A6 I purchased as well [ James  Feb 27, 2016 ]
    Have seen great reviews and can not wait to setup. [ ZION C  Jan 24, 2016 ]

    4 questions already asked

    They come with mounting plates but I'm sure stands would work as well. [ James  Feb 19, 2017 ]
    I have mine mounted on the wall, but I would imagine that they will work just as well if placed on a shelf or stand. They are fantastic speakers and you will not be disappointed! [ FRANK A  Dec 29, 2016 ]
    I have mine mounted. I think they'll work fine either way. [ Robert  Dec 29, 2016 ]
    I have mine mounted to the wall. If the floor stands you have except a wall mount bracket that would work as well. [ Randy  Dec 28, 2016 ]
    Either way. I have mine on the wall. Have these in my vacation home. I have Rti a3 at home also on the wall. Polk make the best all around speaker. [ PATRICK  Dec 28, 2016 ]
    Either way will work. I wall mounted mine. [ jason  Dec 28, 2016 ]
    The speakers are very solid and fairly heavy. I mounted mine on a wall with the integrated bracket, but I'm sure they would do fine on a properly sized speaker stand. [ Rick  Dec 28, 2016 ]
    These can be placed on a stand, table or shelf, as well as wall mounted. [ GEORGE  Dec 28, 2016 ]
    Stands should be ok, depending on location. Like any surround speakers.. location, location, location!!! Stands of course will be fine and work, so Good Luck!! [ Greg  Dec 28, 2016 ]
    1. The Polk FXi A4 will make a satisfactory match for the LSi front speakers. 2. However you would achieve more seamless sound effects when you also add LSi surround speakers. I would recommend the Polk LSi M702 F/X as your surround speakers. [ NORBERT  Jan 31, 2016 ]
    i have all polk speakers and think they all match up well to each other, You cant go wrong. i use the FXI A4 on the sides and back. Love all 4 of them! I have the Polk Monitor 70 as my mains and the Polk CS2 as my center. go for it. [ Martin  Jan 30, 2016 ]
    yes they will and they sound very good [ RICHARD  Oct 07, 2015 ]
    I forwarded your question to an Advisor and they responded with the following: I would try to stay within manufacturer as much as possible. The reason for this has to do with voice matching your speakers. Ideally you want the same type of components in your speakers so that a motorcycle traveling front to back on your speakers will sound the same all the way across. The tweeter on the Polk FXi A4 will be a bit softer of a material and may give you too much of a warm sound versus the bit brighter sound of the Primus you already own. I would look at the Infinity Reference R152 which has a tweeter is made with much closer material than the Polk which will allow it to mesh better. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Oct 06, 2015 ]  Staff
    Yes, both are a good match with the 75T. The FXi A4 is similar in price rage to your 75T. I have the FXi A4's and they produce excellent surround sound. i feel like i am sitting in a movie theatre. [ JOHN B  May 17, 2015 ]