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Polk Audio LSi M 703

Bookshelf speaker (Mount Vernon Cherry)

20 Reviews | 5 questions - 17 answers

Item # 107LSI703C

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Our take on the Polk Audio LSi M 703

Polk's LSi M 703 gives you the kind of high-end performance that's characteristic of the LSi M line's larger floor-standing model, but in a smaller, more flexible bookshelf speaker. You'll hear a wide, deep soundstage with realistic imaging fleshed out in pinpoint detail, and complemented by surprisingly deep bass — even without a sub. Use a pair of LSi M 703s to create a compact stereo music system or as front speakers in a high-end home theater system.

Remarkably realistic performance and a compact footprint

Polk's LSi M 703 gives you the kind of high-end performance that's characteristic of the LSi M line's larger floor-standing model, but in a smaller, more flexible bookshelf speaker. You'll hear a wide, deep soundstage with realistic imaging fleshed out in pinpoint detail, and complemented by surprisingly deep bass — even without a sub. Use a pair of LSi M 703s to create a compact stereo music system or as front speakers in a high-end home theater system.

Building upon the widely acclaimed LSi family of speakers, the LSi M series incorporates the latest developments in speaker technology, fitted into a newly designed enclosure that's beautifully sculpted and luxuriously finished.

Polk's Dynamic Sonic Engine: The speaker within a speaker

Like Polk's larger, floor-standing LSi M models, this smaller bookshelf speaker uses a Dynamic Sonic Engine. Made up of a 3-1/4" midrange driver and a 1" ring radiator tweeter in its own acoustically sealed enclosure, this tightly spaced duo acts like a "mini-monitor." The precise alignment of the midrange and tweeter allows them to disperse sound over a wide, uniform area with excellent off-axis response in the critical 200 Hz to 2,000 Hz midrange.

The ring radiator tweeter features several improvements from the version in the earlier LSi line. A slight reshaping of the tweeter's bullet-shaped phase plug allows it to move even farther out of the baffle, while a redesigned diaphragm has made the tweeter even more efficient.

It even has its own tuned enclosure within the Dynamic Sonic Engine. These changes result in higher power handling, extended dynamic range, improved dispersion, and extended high-frequency response — all the way up to 30,000 Hz!


Advanced driver material for even more realistic sound

The original LSi speakers featured a light, stiff mineral-filled polypropylene cone that was "puffed up" with injected air to form a honeycomb-like structure. The new super cell aerated polypropylene uses larger "puffed cells" to create a cone material that's thicker yet lighter than the original. It's used in both the midrange and woofer, allowing them to move faster and with more efficiency.

This speaker also uses proprietary Orth Crossovers to send the right frequencies to the right drivers, making it extremely efficient and easier for your receiver or amplifier to drive.

PowerPort technology for smooth, deep bass

Like all LSi M speakers, the 6-1/2" woofer has its own PowerPort®. Designed exclusively by Polk, this specially designed "cone" at the mouth of the bass port directs moving air to eliminate bass-stealing turbulence. No turbulence means no wasted power, which means more efficient bass response. You'll hear surprisingly deep bass for a bookshelf speaker that blends smoothly with the mid- and high-frequencies.

Careful cabinet design with a stunning real wood veneer

The '703 cabinet is made of heavily braced 3/4" thick MDF with an even thicker front baffle (1-1/4") to keep distortion to a minimum. Each driver has its own separate, non-parallel chamber to increase the efficiency of each driver and eliminate internal resonances and standing waves. Dual gold-plated binding posts let you bi-amp or bi-wire this speaker for even better performance.

The magnetic grille easily snaps on and off, and it measures less than 1mm thick, so it won't interfere with the sound. And finally, the curved cabinet is finished with a furniture-grade, real-wood veneer that's hand-polished to achieve a gorgeous glow in your home.

Complete your home theater system

Achieve startling realism and seamless surround effects when you build a complete LSi M system. All LSi M models feature the same components and tuning, so you can combine the '706c center channel with any combination of bookshelf or floor-standing speakers in the front of your room, and either additional bookshelf speakers or dedicated surround speakers in the back of your room for wraparound sound effects.

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Product Highlights:

  • frequency response 50-30,000 Hz (-3dB)
  • handles 20-200 watts
  • sensitivity 88 dB
  • 8-ohm impedance
  • 1" ring radiator tweeter
  • 3-1/4" super cell aerated polypropylene midrange
  • 6-1/2" super cell aerated polypropylene woofer
  • PowerPort® technology (for the woofer only) improves bass response
  • dual 5-way gold-plated binding posts allow bi-wiring or bi-amping
  • hand-rubbed lacquer finished real wood veneer
  • 8-7/8"W x 16-3/4"H x 14-5/8"D
  • weight: 29.6 lbs.
  • warranty: 5 years
  • Our 60-day money-back guarantee

What's in the Box:

  • 1 Bookshelf loudspeaker (cherry)
  • Magnetic grille (black)
  • 4 Self-adhesive rubber feet
  • Owner's Manual CD-ROM
  • Quick Start Guide
  • "Read First" note
  • Thank You letter

Smooth sound quality with just enough bass to sound complete when listening to all genre's of music.

denise, Jamaica, NY


Polk Audio LSi M 703 Reviews

Average Customer Review(s):

(20 Reviews)

Polk Audio LSi M 703

Kris from Hudsonville, MI on 12/14/2017

Crutchfield Customer Review (What's this?)

I bought these speakers to replace some older, smaller paradigm titans. I predominately listen to music. I was disappointed with them so my husband took them for his system in our basement. They were too laid back for me and I did not enjoy their overall tone. They did look nice though. If you like a little "punch" in your music search for something else or you will be unhappy.

Pros: Nice looking speaker

Cons: Cost Too laid back, no punch

Polk Audio LSi M 703

denise from Jamaica, NY on 6/2/2017

Crutchfield Customer Review (What's this?)

Smooth sound quality with just enough bass to sound complete when listening to all genre's of music.



Excellent quality for the price.

Dan from Greenville, WI on 1/4/2017

Crutchfield Customer Review (What's this?)

Very nice sounding. Currrently using with a center channel until my home is built with a 5.1 setup. Bass is solid even without my sub hooked up. For the money can't go wrong.

Pros: Full spectrum sound and price.

Cons: My wife wouldn't let me get towers.

Best bookshelf

J. PATRICK from Waterford, CT on 1/2/2017

Crutchfield Customer Review (What's this?)

I replaced a pair of Klipsch 61Bs with Polk LSi M703s for better overall clarity. Klipschs are bright mid range and not that good at high & low. The M703s have a 88db sensitivity that needs more watts to push them. I am using a Parasound amp with 125 watts RMS that make them sound great over spectrum range. M703s have good bass without a subwoofer for the normal application. Wood and construction make for a attractive speakers. Purchase center channel stands because of M703s weight and foot print; using them sideways. Speakers are a great compliment to my B&W 805D speakers and Parasound Int amp with 165 watts RMS with DAC and GoldenEar Forcefield 5 subwoofer with 1500 peak watts.

Pros: Sound, size, frequency response, looks, and value!

Cons: weight and sensitivity

New speakers

Dave from richmond, va on 11/23/2016

Crutchfield Customer Review (What's this?)

I have always had Polk speakers since the mid 80's. My last speakers were Polk Rt7 which had a 7.5 inch woofer and a 1 inch tweeter. I used them in a 5.1 set up that still includes a 15 inch Velodyne sub. I had been looking to upgrade my speakers for years. The Polk TL350's were on sale about 6 months ago as a set of 5 speakers so I bought them. Sound quality was excellent, but kind of small so I returned the set. The 703's were on sale a few weeks ago at half price so I decided to pull the trigger on fronts and a matching center. The sound is a great improvement over my old speakers. The sound is warmer and clearer and I am hearing things in my music I had never heard before. These are very good speakers. One thing to keep in mind is that they will play exactly what you give them. These speakers can easily show you when a recording on a cd is not done well, but give them a clear signal and the speakers just disappear. I was also surprised about the amount of bass they can produce. I am a bass-head, but I sometimes turn off the 15 inch sub just to listen to the speakers by themselves. Well worth the money. I can't wait until they have a few more hours on them so that they'll sound even better.

Pros: Beautiful sounding, well built speakers.

Cons: None

Great Speakers

Tom CW from Vista, CA on 6/25/2016

Crutchfield Customer Review (What's this?)

Great speakers. Hard to believe they are bookshelf speakers. No reason to add a sub woofer. I often use hi res files and USB or BlueTooth input to my amp.

Pros: Great sound, no need for a sub woofer

Cons: Cost

LSi M 703 Are Amazing

chris from CT - Connecticut on 6/13/2016

Crutchfield Customer Review (What's this?)

Recently upgraded from a pair of 17 year old RT-7s. This is a definite improvement in terms of low and response and overall clarity. I plan on picking up the surrounds as well



beautiful looks and sound

william from ky. on 4/8/2016

Crutchfield Customer Review (What's this?)

these speakers sound wonderful and the real wood and finish is really classy,out of the box they were ok when it came to the soundstage but I have read one review where the reviewer said they really open up greatly after 80 hours.These speakers have nice detail and clarity.And the overall sound still is improving with time.I think I will keep these for a long time they are built to last.

Pros: clarity and detail ,and three way design also the option of bi-wiring

Cons: none

Not the best but....

SouthernYankee from Georgia on 8/13/2015

Crutchfield Customer Review (What's this?)

I was first exposed to Polk speakers in the early 70's when I lived near Baltimore where they were founded. I always thought they were over-rated and too expensive for what you got. Ten years later I bought a pair of original Klipsch Forte speakers which are still rated as superior speakers by true audiophiles (before music was all digital!). I still have the Klipsch but need something smaller now for my living space. I looked at the Klipsch bookshelf speakers but wasn't willing to pay thousands of $$ to get the same quality sound I was used to. I tried the RB-61 and it just didn't cut it. Way to shrill and they seemed to be built really cheap. I saw the Polk LSiM703 and thought, "WOW, a 3-way bookshelf with a quality build", and nothing but great reviews on every website I checked. So I decided to give them a try. I'm glad I did. They sound great! I did an 8 hour test of all the genres I listen too (smooth jazz, oldies, country, pop vocals, and some rock, along with live recordings as well as concert dvd's). Oh yes, and the requisite tv digital output. Although not real bright speakers (I'm driving them with a Cambridge Audio receiver with a Wolfsson DAC that I'm sure influences what I'm hearing), they sound very natural to me. The 3-way set-up allows for better transparency than other 2-way speakers, in my opinion. Maybe that's why vocals sound really great. I would recommend them for those who don't want to break the bankk and still get great sound.

Pros: Very sturdy/heavy, well built Nice soothing sound Great bass for a small speaker

Cons: Heavy (30lbs), not for everywhere Low efficiency (88dbm) Need a good quality amp to get good sound

There is no speaker

Dan from New Hampshire on 4/14/2015

Crutchfield Customer Review (What's this?)

It all begins at the source. If you are looking at speakers of this caliber, you must also assume the responsibility of obtaining material worthy of playback. 44.1khz/16bit minimum. Don't bother with MP3. If you listen to MP3, go down to the super center and pick up a set of Beats headphones. Those will suffice for the compressed quality and over compensation of low frequencies. These speakers deserve a quality soundtrack. A decent CD player or equivalent source; Turntables very much acceptable. When I close my eyes, these speakers disappear. Only the music is left standing and it sometimes leaves me in ecstasy. There are times I'm listening while engaged in something else, and I stop everything to look up and make sure I am still in my living room and not on stage with the composers For those who are OCD about their music room decor; I went with the midnight mahogany and they are basically black. You would need a bright light under them to notice the dark wood tone. If your room composes of a black theme, these should fit right in. Alright, I am done ranting. I came from the Polk RTI A3 and these are on another level. Be aware, they are heavy. You will need a sturdy stand. I built mine for $20 at the hardware store. MDF and 2x6 pine.

Pros: Everything?

Cons: Price?

Polk Audio LSi M 703

Cliff from Atlanta, Georgia on 1/24/2015

Crutchfield Customer Review (What's this?)

These are excellent bookshelf speakers. I prefer the three-way design because I find it lends a little more texture and produces cleaner mid-range compared with two-way designs. There are of course caveats to this generalization (three-way vs two-way), but I'm finding my ears prefer three-way designs. I initially purchased the Definitive Studio Monitor 65, which are also capable speakers. But, they sounded a little enclosed and constricted and lacked the presence that I find pleasing in the Polks. The analogy to that would be if somebody was talking with their mouth covered by their hand. Conversely, the Polks sound as if that hand has been removed with clear and present sound. Vocals sound great, the highs are clean defined and the bottom end is tight. I find they are very nicely balanced, have presence, and handle volume well without losing separation. Overall, a very nice soundstage that I think would likely appeal to many. My source is a Denon X4100 which seems to have a very compatable sound signature with these Polks. I realize that sound is very subjective but I hope that this at least gives you a useful frame of reference. The speakers are also aesthetically beautiful (except for the rather large metallic looking Polk badge on the front). Also, I want to give Crutchfield a plug because they really have been wonderful to deal with RE: shipping damage and/or returns if you are simply not happy.

Pros: Nice spread, definition, presence

Cons: I find these speakers are a little power hungry so having a capable amp is necessary to bring out the best in these speakers.

Fantastic Speakers

Ken from Maplewood, NJ on 10/3/2014

Crutchfield Customer Review (What's this?)

In short, the 703s are fantastic speakers, particularly so for a bookshelf design. The 703s replaced a pair of Polk RTi A3s that I have had, and enjoyed, for about three years. They are in the same room, position and used with the same equipment (dedicated music streaming PC, HRT dac, Dynaco tube amp and all AudioQuest cables, source material is a combination of 320kbps streaming and lossless iTunes with the occasional use of a FM tuner, the room is about 500 ft^2 / 4,000ft^3 and relatively 'live') Compared with the RTis, the 703s are substantially more textured, detailed and sound much larger overall despite their being only marginally larger physically - they are about twice as heavy as the RTis which seems to be a good thing. Vocals are really fantastic, a favorite of mine, and the lower registers are substantially more controlled and defied, not all that much deeper per sea, but much improved giving a greater sense of timing and rhythm. Also, the fit and finish are wonderful, very impressive. Keep in mind however that the advantage(s) of the 703s vs the RTis were more clearly apparent as the quality of the source material increased, if you were only to listen to low bit rate streaming, say Pandora, the advantage is much reduced. In sum, the RTi A3s are, on their own, a very good sounding speaker and a fantastic value. The 703's however are a truly fantastic sounding speaker if only a good value, as usual, Crutchfield was great to deal with.

Pros: great sound

Cons: none to date

Polk Audio LSi M 703

C. A. Massa from Chaplin, CT on 6/16/2014

Crutchfield Customer Review (What's this?)

i am very pleased with my recent purchase of the Polk Audio LSi M703 Speakers. Clarity and imaging are excellent for speakers of this (or any) size. They also handle power quite well, and I especially like the "presence" of the mid-range frequencies without the need for any additional coloring or boosting of the signal. I purchased the speakers with the Dark Mahogany finish.... beautiful! They look almost black; but when light hits the cabinets at an angle, you can clearly see the red in the finish. All said, I am very happy with these speakers; I am pleasantly reminded of those boutique speaker systems found only in "Audiophile" stereo shops of the 1970's. A little pricey; but I've learned that you get what you pay for. I would recommend these speakers to a friend.

Pros: Clarity; presence; separation; and construction.

Cons: As said; a bit pricey.

Polk Audio LSi M 703

JamesB from Redding, Ct on 1/7/2014

Crutchfield Customer Review (What's this?)

I really love these speakers. Right out of the box they impressed me. 29.6 pounds each, heavy and solid. The real wood vaneer is beautifully finished; like a fine pc. of furniture. An impressive freq. responce; 50- 30,000 HZ, and a 20-200 watts power range. They are running off of a NAD C165 pre amp and a NAD C275 power amp which produces very clean power. They sound full and musical at low volumes, which was important to me and they have the ability to really stand up and grow some hair. I matched them up with a Polk Audio DSW Pro 660 wi subwoofer and now the whole neighborhood is enjoying the music.

Pros: Quality construction, beautifully finished. Great sound at high, medium and low volumes. (Not the case with all speakers.) Five year warranty parts and labor.

Cons: None

LSiM 703 Perfect for my HT

BobR from Ashburn on 7/1/2013

Crutchfield Customer Review (What's this?)

I bought these to compliment my Polk 705's and 703c. The sounded is near as perfect as what my ear can detect. The re being driven by a Marantz SR7007. With that amp you match the speaker set up for distance, balance and sound quality. I would recommend these to both HT buyers and those who are just into stereo, they are per fort for both formats. Great bottom. Sub hardly needed.

Pros: Build quality, great mids and bass. Very aesthetic.

Cons: None really. Could be price prohibitive, but you get what you pay.

Audiophile Sound at a Fair Price

Anonymous from Boston, MA on 4/25/2013

Crutchfield Customer Review (What's this?)

With the LSiM703, Polk has rediscovered their audiophile roots. Not only does it sound very good; it's also well built, its curved cabinet is attractive in its real-wood veneer, and it's available at a reasonable price for all that it offers.

Pros: Superior sound quality from furniture quality cabinets.

Cons: N O N E .

Polk LSiM 703 book shelf speaker

Leslie from Pioche, NV on 3/24/2013

Crutchfield Customer Review (What's this?)

Fantastic speaker-----all it was billed up to be. Crisp, sharp upper mids and highs without being too bright. Trumpets snap just like being there in person. It's amazing how Polk was able to get such a small driver for the lows to get down that low, without loosing too much gain. The lows are very clean and precise, however many people will probably want to supplement the bottom end with a powered sub woofer, to give more control and gain to those frequencies 80 Hz and down. The cabinet is a work of art, but if that is really Cherry wood, I would have preferred to see some grain and personality to the wood-----it's too perfect to look real.



The Ramblings of a Happy Customer

J. T from South Holland, IL on 11/3/2012

Crutchfield Customer Review (What's this?)

In a multi-speaker showroom situation an truely excellent speaker will often sound unassuming or even a bit bla. If you are smart enough to buy such speakers, you will find that the speakers fall away and only the music is left standing. These wonderful speakers do just that. I highly recommend them.


Cons: None

I Really Thought They Would Be Too Small

Al from Lancaster, OH on 9/18/2012

Crutchfield Customer Review (What's this?)

I read a lot of positive reviews on the LSiM 703 but still I thought they would be too small for my room. I have them on 28" stands, 4' from the back wall, and I sit 15' from them. I use them with 200 watt mono amps and a subwoofer. I do like to turn it up and really expected to try them out and send them back to Crutchfield for something larger. These speakers not only satisfy my volume needs, but they have clarity and image like many of the the much more expensive boutique speakers. The mid-woofer, mid-range, and tweeter are identical to those found in Polk's LSiM 707 Tower Speakers. The cabinets are beautiful, the magnetic grills are cool (just pull them off), and the binding posts are high quality. I had a popular electrostatic speaker before getting the LSiM 703's, and the Polks are every bit as clear and open sounding and a whole lot easier to position in the room. I highly recommend the LSiM 703!

Pros: Clear & Open Sound-Beautiful Cabinet-Easy To Place In The Room

Cons: None

worth the price

jj from Columbia, MD on 11/2/2011

Crutchfield Customer Review (What's this?)

I purchased these after hearing the wonderful lsi tweeter in the blackstone tl3. They are wonderfully musical and good with cinema. They are beautiful but I couldn't figure out how to make them look right in my living room due to my furniture. I felt that I wanted to fill in the low end and move up to the 705s. I may have made a mistake 703s with the 6.5 midrange may outperform the 705s.

Pros: very musical solid midrange rich sound best looking bookshelf I've seen amazing tweeter- super highs

Cons: low end handicapped (bookshelf reality)


Hands-on research

Features and Specs

Enclosure Bass Reflex
Video Shielded No
Tweeter Type Ring radiator
Tweeter Size (inches) 1
Midrange Size (inches) 3.25
Woofer Size (inches) 6.5
Woofer Composition Super cell aerated poly
Woofer Surround Rubber
Power Range 20-200
Sensitivity 88 dB
Impedance (Ohms) 8
Frequency Response 50-30k Hz
Connector Type Post
Bi-amp Inputs Yes
Height (inches) 16-3/4
Width (inches) 8-7/8
Depth (inches) 14-5/8
Weight (pounds) 29.6
Mounting Bracket Included No
Recommended Stand Height (inches) 30-36
Parts Warranty 5 Years
Labor Warranty 5 Years

Product Research

Driver Technology
Enclosure Design
Mounting Options

Driver Technology

Performance Objectives of the Polk Audio LSiM Series Loudspeakers: The LSiM series loudspeaker is Polk Audio's best high-performance loudspeaker. Polk Audio designed the LSiM series loudspeakers to create a sound that virtually transports you to the scene of the recorded performance. It was engineered & created with the following performance objectives in mind.

  • Pleasing tonality, even during extended listening at performance levels.
  • Crisp, lifelike impulses, transients & coherent detail without any unnatural ringing or decay.
  • Natural reproduction of complex low frequency instruments & special effects.
  • Uniform sonic representation within the listening area & immersive spatial impression.
  • Reproduce concert/theater levels while maintaining linearity and accuracy.
  • Compatibility with a wide array of electronics both past, present & future.
  • Work as promised for many years of enjoyment (5 year parts & labor warranty).

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, & low distortion.

3-Way Driver System: The Polk Audio LSiM series bookshelf loudspeaker employs a 3-way driver system for crisp, detailed highs; natural, lifelike midrange; and accurate, dynamic midbass. The bookshelf loudspeaker houses a 1" (diameter) Dynamic Balance Enhanced Ring Radiator Tweeter, a 3.25" (diameter) Dynamic Balance Super Cell Aerated Polypropylene cone midrange driver, & a 6.5" (diameter) Dynamic Balance Super Cell Aerated Polypropylene cone midbass woofer.

Enhanced Ring Radiator Tweeter: The ring radiator tweeter was a vital element in the success of Polk Audio's original LSi Series. Polk Audio engineers have made some nuanced improvements in the design of this tweeter. First, they reshaped the tweeter's bullet-shaped phase plug, allowing it to move farther out of the baffle, improving dispersion and eliminating horn-loading. Next, they opened up the tweeter's face-plate, then redesigned the tweeter's diaphragm roll to make it more efficient and improve dispersion even more. Finally, they gave the new ring radiator tweeter its own tuned enclosure (Dynamic Sonic Engine). This new ring radiator tweeter boasts higher power handling, extended dynamic range, improved dispersion and extended top-end response.

Super Cell Aerated Polypropylene (APP) Cone Woofer: If the perfect cone material is lightweight (for faster, more efficient action) and stiff (for less distortion-causing flex), with enough internal damping to suppress and offset any limitations of its lightweight stiffness, then the Super Cell APP Cone Material is about as perfect as cone material gets. Aerated Polypropylene (APP) is a mineral-filled polypropylene material that's been "puffed up" with injected air to form a honey-comb structure. Polk Audio's original APP cone approached the ideal balance of lightweight stiffness with high damping, along with good resistance to moisture, UV and temperature extremes. Next generation LSiM series loudspeakers employ Polk Audio's next generation of APP Super Cell. In Super Cell APP, the "puffed cells" are larger, for a thicker cone material that actually has less mass than the original APP material. Super Cell APP has larger cells, for lighter weight and more inherent damping, plus uncompromised stiffness, for unsurpassed transient response and resonance suppression.

Butyl Rubber Surrounds: Durable, soft, injection-molded butyl rubber surrounds are tuned to absorb and suppress unwanted cone resonances. Polk Audio's butyl rubber material is impervious to UV, extreme temps & humidity, for a lifetime of smooth, reliable sound.

Extended Linear Motion Voice Coils: Allowing lots of movement in a limited space, ELM Voice Coils power the LSiM series speaker's mid-range & mid-woofer drivers to extend their higher-frequency response with much less impedance.

Cast Aluminum Baskets: These lightweight, cast aluminum baskets provide a rigid structure for precise alignment of the speaker's active parts, for flat response & low distortion, with no mechanical resonances or ringing. The open design provides ample venting for unobstructed linear movement.

Orth Crossovers: The Polk Audio LSiM series bookshelf speaker employs proprietary engineering, designed and patented by Polk Audio to maintain a lower order crossover design & increase power handling. Orth Crossovers feature Mylar/polypropylene capacitors for sparkling highs & Air Core Inductors for superior transparency. Notch Filters and sophisticated Zobel circuits smooth the impedance curve of the system for more efficiency & better high frequency response.

  • Tweeter/Midrange Crossover: 2.8 kHz 18 dB/oct
  • Midrange/Midbass Crossover: 300 Hz 12 dB/oct

Timbre-Match Series: You can achieve incredible realism & seamless surround effects when you build a complete Polk Audio LSiM series speaker system. All LSiM series speaker models feature the same components & tuning for perfect timbre-matching.

Frequency Response Note: The overall frequency response is 36Hz to 40kHz & the -3dB frequency response is 50Hz to 30kHz.

Enclosure Design

Real Wood Veneer: The Polk Audio LSiM loudspeaker is finished in a real, natural, furniture-grade wood veneer.

MDF Enclosure: The enclosure is an integral part of the sound design of the Polk Audio LSiM series loudspeaker. All LSiM cabinets are made of .75" MDF, with wide-radius baffles of robust 1.25" MDF. Substantial internal bracing (each driver has its own separate non-parallel chamber) increases efficiency and banishes internal resonances & standing waves, for high power handling and incredible smoothness. Wide-radius baffles, along with zero-diffraction magnetic grilles, help stabilize imaging for a very wide, well-defined soundstage.

Dynamic Sonic Engine (DSE): At the heart of the Polk Audio LSiM series bookshelf loudspeaker is an enclosure-within-the-enclosure design (known as the Dynamic Sonic Engine) that houses the mid-range driver & the ring radiator tweeter. Molded into one rigid piece, the DSE enclosure tapers to a "turbine" that reduces back-wave reflections. The DSE combines its two speakers in an aligned, optimized array for wide, uniform dispersion in the critical 200Hz-2kHz midrange, improving transient response. The combination delivers exact timbre-matching, improved high-frequency dispersion and greater horizontal off-axis response.

Note: The ring radiator tweeter & midrange driver are housed in a separate internal sealed enclosure from the ported enclosure which houses the midbass woofer.

PowerPort Bass Venting: PowerPort Bass Venting is a Patented Polk Audio technology that uses a specially designed "cone" at the mouth of the bass port to direct moving air as it exits the port. Air moving out of a bass port creates turbulence, which can result in boomy distortion & "port noise", especially at high volume. This distortion can cause bass output losses up to 3dB, wasting lots of amp power. To eliminate bass-stealing turbulence at the mouth of the port, Polk Audio engineers designed the PowerPort. It's unique shape promotes "laminar" airflow even in short tube ports by mimicking the properties of longer, flared port openings. No turbulence means no wasted power, which means more efficient bass response.

Zero-Diffraction Magnetic Grille: The super thin (1mm), zero-diffraction grille has no measurable effect on the speaker's response. Completely unobtrusive, stylishly sheer; the grille locks into place magnetically.


Dual Gold-Plated Binding Posts: The bookshelf loudspeaker has two sets of gold-plated binding posts connected by wire-jumpers. The gold-plated binding posts will accept bare wire (16-12 AWG), pin connectors, spade connectors, & banana plugs (single only).

Bi-Wiring/Bi-Amping: Using the dual posts, you can bi-wire or bi-amp the speaker. Bi-wiring or bi-amping the speaker provides improved bass & treble performance. If you decide to bi-wire or bi-amp, you must remove the jumpers between the terminal posts (failure to do this could result in damage to your amplifier and loudspeakers).

  • Bi-Wiring: Bi-wiring can provide noticeable improvements in the overall transparency of your loudspeakers. Run separate speaker wires to the low & high frequency drivers from a single amplifier (the upper set of binding posts are for the high frequency drivers; the lower set of binding posts are for the low frequency drivers).
  • Bi-Amping: Bi-amping allows you to use separate amplifiers for the high & low frequency sections of your loudspeaker for greater dynamic range & lower distortion. We recommend that your separate amplifiers have identical gain to preserve the speaker's voicing balance.

Color-Coded: The bookshelf speaker's binding posts are color-coded (red/black) for easy identification between positive & negative.

Mounting Options

Placement: The LSiM series bookshelf loudspeaker is designed to provide excellent performance on a bookshelf or placed on a floor stand. For best results place LSiM bookshelf loudspeaker so the tweeter height is within 6" of your seated ear height.

Positioning: The LSiM series bookshelf loudspeaker can be used as a front speaker or rear-channel surround speaker.

  • Front Application: To enjoy the most realistic stereo image and lifelike sound, place the speakers so that an equilateral triangle is created between the speakers & your favorite listening position. Angle the speakers toward the middle as necessary in order to support a more solid center image. Experiment with the distance between your speakers & both the back/side walls. You'll experience some bass boost with the speakers located closer to walls.
  • Rear Application: If you are using your LSiM series bookshelf loudspeaker as a rear channel in a home theater system, it should be placed on the rear or side wall, slightly above (and, on the side wall behind) the listening position. Angle it toward the listening area if possible.

Rubber Feet: The bookshelf speaker comes with 4 self-adhesive rubber feet so it will sit securely on your stand or shelf.

Note: The speaker does not offer any wall-mount options.

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Product reviews from the Crutchfield Labs

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Customer Q&A

Crutchfield asked  
Why did you buy this?

reviews [ Wayne  Jan 18, 2018 ]
After speaking with Stone the rep who gave me great advice and product info I believe my decision was the best for me and my music. Can't wait to spin my vinyl again and rock the house. [ Michael  Jun 07, 2017 ]
My main speakers, love the sound with Miles Davis or John Coltrane playing. Very pleasing. The only speakers I own are Polk Audio, like their sound and they fit my budget. [ Scott  Jan 04, 2017 ]
The 1/2 list price, 5 star reviews, large bookshelf, Polk history with other speakers, Crutchfield service, and online pro reviews! [ J. PATRICK  Dec 21, 2016 ]
I've been listening to a pair of RTi A3's, and a PSW108, thought it was time for a bigger sound. [ Joe  Feb 01, 2017 ]
I'm a long time listener of polk speakers I have SDA's it's time to upgrade I like how the LSi M sounds. [ John  Nov 09, 2016 ]
Excellent look, performance and size. [ John  Jul 25, 2016 ]
I own other polk products it was between these or paradigm prestige 15b [ shannon  Jan 18, 2016 ]

5 questions already asked

Lsim703 will make a good front set of speakers for a small to medium size room. Not sure if the Lsim703 will over power the RTI 100 because I have not heard them. [ John  Mar 08, 2017 ]
In order to achieve the best sound, it is best to timbre match speakers. What that means is if you purchase LSi fronts you should also purchase a rear speaker that is in the LSi series. So I would recommend to purchase the best RTI speaker you can afford. In a 5.1 configuration the center channel is extremely important, followed closely by the right and left front. Hope this helps. [ Daniel  Mar 07, 2017 ]
think you will improve overall sound of your system without 703s overpowering other speakers. my own preference would be for a mached system. that said, the 703s ain't cheap [ JAMES R  Mar 06, 2017 ]
The overpower is not a concern; but your watts per channel may be! These speakers have a effiency rating of 88! So you need a minimum of 100 watts RMS! With a 5.1 will your receiver put out 100 watts RMS? Great speaker that I push with 125 watts from amp! [ J. PATRICK  Mar 06, 2017 ]
Hi, I have bought a pair of these speakers and I can tell you they meet my expectation in terms of quality, clarity of sound, no distortion, and elegance. They are indeed a bit expensive but the sound is equivalent to the one produced by bigger speakers. I really don't regret the investment. I listen various style of music from classical piano to jazz, passing by pop rock and the speakers are very polyvalent. I hope this will help you making your choice. [ Guillaume  Jul 28, 2015 ]
Hi William T R! I am passionate about the sound from Polk speakers. I have a center channel in addition to the LSi M 703. They don't just "really sound good" but they sound fantastic. Whether you listen to classical, jazz or rock, the range and clarity of sound from Polk does not disappoint. It is an investment that I cherish each time I crank the volume. [ JEFFREY R  Jul 27, 2015 ]
These are well designed speakers. I replaced a set of tall speakers with these and found they supplied all the range in less space. I did get the free Polk subwoofer to supplement my movie watching, but don't need that for music. [ RICH  Jul 27, 2015 ]
True, they need to back it up, and I think they do... I think they are reasonably priced... the placement of them will be important as always to get best effect.... since buying these, I've bought some Magnepan 1.7i's and also some Revel F208's... the Revel's cost about $5K, though I got mine for $3K used. I still listen to the Polk's even with more expensive speakers around. The Polk's are good. [ William  Jul 27, 2015 ]
You don't want tall unless you are standing during the listening! If you are sitting the stands should have the speakers at eye level! 15 to 24 inch at the most! Because of the size of 703s I purchased two center speaker stands that are about 16 inches high and 14 inches long to accommodate the large base! [ J. PATRICK  Jun 17, 2017 ]
i have 36 inch stands i bought about ten years ago when i had the polk lsi9 speakers. several articles i've read over the years suggest 36 inch hight is a good fit for book shelf spkrs [ JAMES R  Jun 16, 2017 ]
The best stand for LSIM 703 is 26-30 inches [ JOHN  Jun 16, 2017 ]
If you have a good amp putting out 50 watts it should sound fine but LsiM line of loud speakers likes alot of power, mines are running with 135 watts and sound great. Hope this helps. [ John  Dec 31, 2016 ]
I am running them at 100 watts each and they seem to take a little more to push them than my older Polk speakers. I think they would sound okay (these things are amazing), but would probably not sound up to their potential. [ David  Dec 31, 2016 ]
Minimum recommend power is 20 W. Not an expert but I imagine that they will sound great at lower volume levels. A problem with any underpowered amp is clipping. When you try to listen to something at high volume the amp won't be able to deliver and you end up sending a clipped signal to your speakers which can damage them. I've heard it's better to have an amp that exceeds your speakers max rated voltage (headroom) than to under power them if you like loud music [ chris  Dec 31, 2016 ]
with the power mentioned i'm thinking the listening area is small. i think 50 watts will work out fine. i have four lsim 703s and a lsi center i use in a 5.1 setup. for music i don't turn up the volume that high. i'm using a sony ZA3000es AVR that is rated at 100 watts per channel [ JAMES R  Dec 30, 2016 ]
50 watts is not adequate for this speaker because its sensitivity is 88dBs! I am pushing it with a Parasound amp that is rated at 125 watts RMS! I would think that 100 watts is minimum! Look for two way with higher sensitivity and lower watt handling max. [ J. PATRICK  Dec 30, 2016 ]
Hello, I actually had the Marantz PM6005 & PM6006 in my home prior to finally purchasing the Cambridge. I really enjoy the Marantz and their warmth. I also own the older PM7000 and use it on a second system. However, the Cambridge CXA60 was a huge surprise. This amplifier IMO punches a bit above its rating and I feel like both the other Marantz models are a bit too laid back for my liking. I found myself needing to constantly adjust the volume, and direct controls on the Marantz. This was not an issue with the Cambridge CXA60. The sound is warm but not overly so. I feel like their new pieces are great matches for a wider variety of speakers, whereas the Marantz stuff does require a bit more "pairing" attention. It broke my heart to send back a Marantz for a shot in the dark on this Cambridge but man I'm glad I did! If I didn't already own a cd transport that I was very happy with i would have purchased the Cambridge transport as a partner to the CXA60 also. I cannot recommend the CXA60 enough! I hope this helps. Pros - Warm sound across the board Great design and looks High quality components Nice weighty remote with very basic controls, also compatible w/other Cambridge pieces Seems more powerful than its rating suggests Cons - Not exactly a "budget" price but I feel it's well worth it Again, hope this helps. Cheers! [ Derek  Nov 11, 2016 ]