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Polk Audio LSi M 707

Floor-standing speaker (Midnight Mahogany)

10 Reviews | 1 question - 4 answers

Item # 107LSI707M

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Our take on the Polk Audio LSi M 707

Immerse yourself in smooth, high-end sound that envelops and caresses you thanks to Polk's LSi M 707. 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. You'll hear a wide, deep soundstage with realistic imaging fleshed out in pinpoint detail, and anchored by effortlessly deep bass. It'll faithfully reproduce your most demanding audio sources from top to bottom, without any help from a separate subwoofer. It makes an excellent pair in a stereo music setup or becomes the shining star in a knock-out home theater system.

Luxurious sound from Polk's gorgeous, flagship floor-standing speaker

Immerse yourself in smooth, high-end sound that envelops and caresses you thanks to Polk's LSi M 707. 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. You'll hear a wide, deep soundstage with realistic imaging fleshed out in pinpoint detail, and anchored by effortlessly deep bass. It'll faithfully reproduce your most demanding audio sources from top to bottom, without any help from a separate subwoofer. It makes an excellent pair in a stereo music setup or becomes the shining star in a knock-out home theater system.

Polk Audio LSi M 707 Floor-standing speaker

Add incredible sound — and great looks — to your home's entertainment system.

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

The heart of the LSi M 707 is Polk's 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.

Rich lifelike details, with crisp mids and highs

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 midbass drivers, as well as both woofers, allowing them to move faster and with more efficiency.

Dual woofers deliver smooth, effortless bass

Low on the '707's front baffle you'll notice dual 6" x 9" woofers. The oval shape helps them produce tight low-frequency music and movie sounds while maintaining a narrow cabinet width. Plus, each woofer has its own PowerPort® — a unique Polk design that positions specially designed "cones" at the mouth of the bass ports to direct moving air to eliminate bass-stealing turbulence. No turbulence means no wasted power, which means more efficient bass response.

Four-way design for clear, low-distortion sound

The LSi M 707 features a 4-way design, meaning that the tweeter handles only the highest of frequencies, the midrange handles the middle frequencies, the midbass handles the mid to low frequencies, and the woofers handle only the lowest frequencies. This separation allows each driver to perform within its optimum range, meaning you'll hear sound with absolute clarity and stunning impact. And this speaker uses proprietary Orth Crossovers, making it extremely efficient and easier for your receiver or amplifier to drive.

Careful cabinet design with a stunning real wood veneer

The '707 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 create any combination of towers in the front of your room with a center channel speaker for crisp dialogue, and either bookshelf speakers or dedicated surround speakers in the back of your room for wraparound sound effects.

Product Highlights:

  • frequency response 38-30,000 Hz (-3dB)
  • handles 20-300 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 midbass
  • dual 6" x 9" super cell aerated polypropylene woofers
  • dual PowerPort® technology (for the woofers only) improves bass response
  • dual 5-way gold-plated binding posts allow bi-wiring or bi-amping
  • hand-rubbed lacquer finished real wood veneer
  • 9-1/2"W x 50-13/16"H x 18-7/16"D
  • base measures 10-1/2"W x 20"D
  • weight: 99.2 lbs.
  • warranty: 5 years
  • Our 60-day money-back guarantee
  • sold individually

What's in the Box:

  • Floorstanding loudspeaker (black)
  • Magnetic grille (black)
  • 4 Spiked feet (installed)
  • 4 Rubber feet (installed)
  • 5mm Allen wrench
  • Owner's Manual CD-ROM
  • Quick Start Guide
  • "Read First" note
  • Thank You letter

These things sound and look AWESOME. if you get them you won't be disappointed. Lots of $ but well worth it. Very detailed spacious sound. The enclosures are like fine furniture Best I've heard and seen! Can't beat Crutchfield.

Steve, Michigan


Polk Audio LSi M 707 Reviews

Average Customer Review(s):

(10 Reviews)

Polk Audio LSi M 707

Crutchfield customer from Salt Lake City, UT on 1/3/2018

Crutchfield Customer Review (What's this?)

Just replaced my old LS70's with these bad boys. I run them with an old Adcom high current amp and the resulting sound is awesome. Much better bass response than my old towers. They have a very discreet sound presence with very musical attributes. Good for all types of music. Could not be happier.

Pros: Great punchy bass and exceptional musical clarity.

Cons: Weight, you need a forklift to haul them around.

These Polk LSIM 707s have ended my speaker search.

Gordon from Holliston, MA on 12/4/2016

Crutchfield Customer Review (What's this?)

I wouldn't call myself an audiophile, but as a 51-year-old life-long music lover and musician, I do have fairly high standards. For the past year I've been collecting vintage gear for my 2-channel music room in the basement, so this review is in that context, as my home theater set-up is in a separate room upstairs. My source units include Sansui (7070, G6000) and Pioneer (SX850) receivers with modern mid-level CD players and turntables connected. I've been rotating through vintage speakers, trying to find a full-range solution that didn't require a sub. Nothing wrong with using subs, of course, as I have a nice one in the home theater, but I just prefer a simple two-speaker approach for stereo music. I tried various respected vintage speakers such as Klipsch KG4, EPI 150, Ohm Model H, Bose 601 and 10.2 (both Series 1), DCM TimeWindow 1A, and Advent 5002, but I wasn't totally satisfied, primarily on the low end. Next I stepped up to a new pair of Klipsch RF62ii, but found them to be a little heavy in the mid-bass, but lacking in the low end, which is typical of modern home theater towers. I returned those (thank you Crutchfield!). When I saw these Polk's on sale for half price they caught my eye, and I found a few very favorable reviews on true audiophile websites. I pulled the trigger and couldn't be happier! Wonderfully balanced highs, mids, and satisfying low bass. Spacious musicality that completely out-classes all of those other speakers. My search is over.

Pros: - Beautiful asthetics. - Very solid high-quality construction. - Excellent, smooth full-range tonal balance and detail. - Very nice imaging. - No harsh/fatiguing upper mids. - No mid-bass hump. - Very solid low end foundation that requires no sub for most types of music.

Cons: - Large and heavy (but they need to be to perform as they do). - More than I initially wanted to spend (but totally worth it in hindsight). - Might still need a sub for ultra-low bass like pipe organ, techno/electronic music, or home theater.


Steve from Michigan on 4/6/2016

Crutchfield Customer Review (What's this?)

These things sound and look AWESOME. if you get them you won't be disappointed. Lots of $ but well worth it. Very detailed spacious sound. The enclosures are like fine furniture Best I've heard and seen! Can't beat Crutchfield.

Pros: Awesome sound and looks

Cons: Can't think of any


donald from Vallejo, CA on 4/6/2016

Crutchfield Customer Review (What's this?)

I like the speakers. Still trying to figure out how to get the best sound out of them.

Pros: sound good at any volume, They look nice too

Cons: very heavy.

Polk Audio LSi M 707

Brianjt from California on 10/4/2015

Crutchfield Customer Review (What's this?)

They far exceeded my expectations, I upgraded from a set of Polk Monitor 70's that have been my main speakers for 10 years and have been great. But I have to say it was like trading in a 10 year old Malibu for a new Corvette Stingray, it was that big of change. They are awesome, you will not be disappointed. I also got the Lsim 703's for the surround speakers and a Lsim 704 center channel (the 706 was to big for my cabinet), makes for an awesome listening experience. Listening to 7 channel stereo with your eyes closed you swear hour sitting in the middle of the performance. A little pricey but worth every penny. I saved 800.00 on the set through scratch and dent and the only issue I had was the grille on one of the units was slightly bent, an easy fix, no others flaws were found.

Pros: Won't disappoint Look and sound beautiful

Cons: Heavy, have some help unpacking and setting up.

Polk 707's, an orgasm for the ears

justin from Florida on 8/2/2015

Crutchfield Customer Review (What's this?)

After 30 years with Advents, was is a financial position to upgrade my entire stereo; speakers are everything as you know and went with these, sight unseen, only speaking with pros and reading articles. A big, beautifully constructed masterpiece which delivers music with the force of a 747 while delivering crisp, concise notes. Volume is not needed to "hear" the music.. but they CRANK! I have mine hooked to a Yamaha S2000... They are visually astonishing; a work of art,a piect of furniture. And the sound is just unbelievable. I truly can not compile a list of adjectives to describe these speakers and still give them justice. It was worth the cost and the wait.

Pros: -quallity craftmanship -distortion-free music

Cons: -size, these guys are big

Polk Audio LSi M 707 Review

Chris B. from Valencia, California on 7/2/2015

Crutchfield Customer Review (What's this?)

I purchased the Polk Audio LSIM 707's in May of 2014. In short, these Speakers are the most Accurate, Fullest Sounding and Precise speakers I've ever listened to or have owned, for under $10-$15K pair. The Bass is extremely precise, deep, and tight and goes well below the published specification of 38Hz. I've measured, with my spectrum analyzer, -3db @ ~28Hz with sound pressure well down to 20Hz.The Mid-Bass, Midrange and Highs are exceptional, Clear, Detailed and Precise with no "harsh edge". The Soundstage is Deep and Wide, it is as if the Musicians are present and "live" right at home in my listening area. Polk has created a fabulous product that has far exceeded my expectations! I'm running the speakers in a bi-amp configuration, using a Yamaha A-S2000 to drive the Bass and Yamaha A-S2100 (this as the Master) to drive the Mid-Bass, Midrange and Highs. The Soundfield performance is truly astonishing! (Please see my reviews on both these Yamaha's) For Speaker Cables I'm using 2 pairs of the AudioQuest Rocket 33's (Please see my review on the Rocket 33's). I've reversed the cables so that 4 banana plugs for each left and right channel(s) are plugged into the Yamaha's and have the Yamaha's speaker output select switches set to A+B. As stated, you're not going to do better then this unless you're willing to spend $10K+ at minimum. Out of the box, I was blown away; however, break-in time for these speakers was around 60-100 hours. After that, they really "settle-in".

Pros: Highly Recommended if you have the right gear driving them. Beautiful, High-Quality construction like the finest furniture! There is content in my now 30+ Year CD collection that I've never heard until now, with the LSIM 707's / Yamaha A-S2x00's combination!

Cons: These speakers are real "Beasts"! Make sure you have a buddy around to help with the Setup and Placement.

Great experience Polk Audio LsiM707

rickybobby from Crown Point, IN on 12/14/2014

I currently run a 7.2 Emotiva UMC-200 preamp and a Emotiva XPA-2 & XPA-5 and purchased the new Polk Audio LsiM707 tower speakers the Polk Audio LsiM703 bookshelf speakers 4 of the 703's and the Polk LsiM706c all in midnight mahogany and I am smitten kittens ( blown away ) at the quality of these speakers and not to mention the beautiful sound they emit! For instance when I am listening to them in 2 channel mode it feels like the rest of my speakers are still on. The 2 707's alone fill the room with magic you are just submerged in every little detail of the music just close your eyes and you feel the music they play imagin is perfect the midrange drivers do a wonderful job I would have to say that they take a good 100 hrs to break in. Also have 2 Polk Audio DSWPRO-660i on bass duty

Pros: I love these speakers, I could have bought Bowers & Wilkins 802 Nautilus but they were harsh on the ears I can listen to the Polk Audio LsiM707's and the rest of my LsiM series of speakers for hours without any fatigue on the ears. I listened to a lot of Expensive Speakers costing more than 5 times than that of the Polk LsiM series but none of them could beat the polk's with the LsiM707 not 1 thing stood out everything stood out and that's how I like it that is a true audiophiles speaker.

Cons: No other speaker has a chance in and around the $10,000.-$15,000 range because once you hear the LsiM707 speakers with a good power amplifier you would realize that Polk hands down built one of the best all around audiophile speakers and the rest of the other brands is just wasted cash. I'm not saying that the other brands I heard aren't good but it's like they would only stand out in one area mids highs but not in the bottom end . And that's exactly what Polk did by building there LsiM series

Polk Audio LSI M707 Floor Speaker

William P. from Naples, FL on 8/28/2014

I bought the M707's with the intention of not having to purchase another set of lead speakers for myself again for many many years - if ever again. These speakers each composed of five powered speaker cones/woofers require a lot of power. I am currently powering mine with a 70 W per channel, well reviewed, tube amplifier which I've only had since I bought the speakers. I may keep the tube amplifier for other purposes in the future and purchase a pair of "Mono blocks" to power these babies. They sound good now - knowing that my current main limitation is the acoustics of my room and possibly an under powering amp. They certainly need to breath and have a lot of clean power backing them up to perform as designed - I'm sure. Also I think space to pull them out away from the front wall helps their sound so consider this also - basically you need a lot of space. But that is certainly a consideration for any speakers at this level of power and consumer expectations. That being said, I just love them. They look great, don't distort at all at any power level I able to give them, and hit all phases and frequencies well. Of course you may want to have some kind of equalization to be sure the tones fit your listening preferences.

Pros: Pros include a huge appetite for whatever you throw at them. The ability to bi-amp the speakers. Super high-quality furniture finish and construction, and extremely thin magnetic grill and covering that looks fantastic and can easily be removed and replaced with no damage to the cover or speakers, and of course a well - documented and respected track record, engineering, and production history for decades by Polk Audio. Not to mention a fantastic full five year warranty.

Cons: So far the only con I can come up with for the speakers is the fact that I probably could supply a better power source for them. Otherwise most likely I would've given five stars.

Polk Audio LSIm707

Danimal from Henderson NV on 11/20/2011

Crutchfield Customer Review (What's this?)

Have owned several higher end speakers over the years and these are just about the best, especially at this price point. Sparkling highs, realistic mid-range voice; solid, tight bass--can momentarily be a bit boomy lower-mid range on some material, but tweaking speaker location helps put an end to that. These speakers present a great soundstage with a great sense of space and openess around each individual sound--they also seem to be able to very competently present every detail and nuance of the program material without losing small soft details to louder sounds that occur simultaneoously. Sound surprisingly good even at lower volume settings for such large speakers and have tremendous dynamic range---you will need quite a bit of power to drive these, especially at higher volume settings. Appear to be an outstanding value for the money and are not only great to listen to but pleasing to look at.

Pros: Great look--great sound

Cons: Not really a dislike--but be prepared--these are large, heavy speakers--not easy to move them about to tweak the sound, especially on a carpeted surface


Hands-on research

Features and Specs

Enclosure Sealed/Ported
Finish Wood veneer
Color Black
Tweeter Ring radiator
Tweeter Size (inches) 1
Midrange Size (inches) 3.25
Woofer Size (inches) 6 x 9
Woofer Composition Super cell aerated poly
Woofer Surround Rubber
Built-in Powered Sub No
Video-Shielded ---
Connector Type Post
Bi-amp Inputs Yes
Parts Warranty 5 Years
Labor Warranty 5 Years
Power Range 20-300
Frequency Response 38-30k Hz
Sensitivity 88 dB
Impedance (Ohms) 8
Subwoofer Amp Power ---
Height (inches) 50-13/16
Width (inches) 10-1/4
Depth (inches) 20
Weight 99.2 lbs

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.

4-Way Driver System: The Polk Audio LSiM series floor-standing loudspeaker employs a 4-way driver system for crisp, detailed highs; natural, lifelike midrange; accurate, dynamic midbass; & deep, rich bass. The floor-standing loudspeaker houses a 1" Dynamic Balance Enhanced Ring Radiator Tweeter, a 3.25" Dynamic Balance Super Cell Aerated Polypropylene cone midrange driver, a 6.5" Dynamic Balance Super Cell Aerated Polypropylene cone midbass woofer, & two 6"x9" Dynamic Balance Cassini Oval subwoofer drivers.

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.

Cassini Oval Subwoofer Drivers: The Polk Audio LSiM series floor-standing loudspeaker uses dual Cassini oval subwoofer drivers. The Oval woofer shape increases surface area for deeper, more musical low-frequency response, while allowing for a narrower baffle design. The overhung voice coil design allows larger excursions & higher power handling. As a result, the bass response is deep & blending is smooth.

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.

Enhanced 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. The LSiM subwoofer drivers use Overhung Voice Coils, which allow the larger excursions and greater power handling necessary for big subwoofer performance.

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 floor-standing 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: 3 kHz, 18 dB/oct
  • Midrange/Midbass Crossover: 300 Hz, 12 dB/oct
  • Midbass/Subwoofer Crossover: 100 Hz, 6 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 20Hz to 40kHz & the -3dB frequency response is 38Hz 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 floor-standing 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, & midbass woofer are housed in a separate internal sealed enclosure from the ported enclosure which houses the two oval subwoofer drivers.

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 floor-standing 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 floor-standing speaker's binding posts are color-coded (red/black) for easy identification between positive & negative.

Mounting Options

Placement: To enjoy the most realistic stereo image and lifelike sound, place the floor-standing 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.

Rubber Feet & Adjustable Floor Spikes: Rubber feet & adjustable floor spikes are included with the LSiM floor-standing loudspeakers to anchor & stabilize the speaker on any type of floor (carpet, tile, or hardwood).

  • Spiked Feet: The floor-standing speaker includes 4 pre-installed adjustable spiked feet. These adjustable spiked feet allow you to tilt the speaker backwards or forward a tiny bit in order to optimize your listening area. Most floor-standing speakers are adjustable only from the bottom of the base & require you to tip the speaker over using two hands to access the floor spikes. The LSiM floor spikes are adjustable from the top of the base using the included 5mm hex (Allen) wrench.
  • Rubber Feet: The floor-standing speaker's 4 pre-installed adjustable spiked feet come covered with rubber protection tips to protect your hardwood or tile floor. These rubber tips are removable.

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.

Staff Reviews

Product reviews from the Crutchfield Labs

What are the Labs?
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

I have a pair of RTi A9s. After reading numerous reviews about the LSi M707s and its superior sound quality, I decided to upgrade. The sound from the 707s is better as expected. The additional investment is worth the audio improvement. [ DANNY V  May 14, 2017 ]
It got good reviews without being too expensive [ ROBERT  Jul 01, 2016 ]

1 question already asked

Thanks much! Your feedback is greatly appreciated. I'm going to Magnolia to hear an audition of Definitive Tech Mythos ST-L Super Towers, I've heard some good reviews of these speakers, again thanks. [ Bill  Aug 29, 2014 ]
These Polks are amazing! I have them paired with LSim707 book shelf speakers, LSi706c center channel, Polk 550 and 660 subs and FXi A6 surround. I watch blueray and listen to music extensively. The pros are the sound quality and attractive cabinets. Only con is the weight of these monsters, getting them to sit exactly where I wanted them was difficult and should require 2 people. This is my second set of Polk towers. The originals are 10 years old and sound amazing and are now in my man cave. [ GUNTER  Aug 26, 2014 ]
POWERFUL. I am pushing mine with a Jolida 801BRC 70WPC sweet tube amp (w/6550's)... JUST enough power... Remember each of these towers house (5) POWERED speakers, weigh 100lbs. ea., and they can be attached to (2) amps EACH. My advice: Have space, a lot of clean power, some form(s) of equalization, and HAVE FUN. I have a separate powered subwoofer in the room with them because I already had it. They produce VERY good base even w/o it. [ William  Aug 26, 2014 ]
So far, for what they purport to be, I do not think they are particularly good. I have them hooked up to a NAD M2 Direct Digital Amplifier playing HI Res Flac files. They are no where near as good as the the itty bitty Totem Model One bookshelf speakers, (on speaker stands), I thought I would replace them with. They are not as good as an old pair of mirage M-290 bookshelf speakers I have either. That said, they do sound quite a bit better now after perhaps 100 hours of playtime then they did out of the box. It may also be you have to really crank these speakers up for them to show their stuff. The M2 can do that, but this is not the every day way I listen to music. In my opinion, they are particularly lacking in prescense, staging, and timbre. This does improve somewhat if you place them some distance from the walls. All in all, very disapointing really. I am considering returning them and I would have already if they wheren't so big. I didn't really shop around for any other floor standing speakers. These where being offered at a substantial discount so I took a shot and just bought them, figuring, "how bad could they be". Sad to say, for a "flagship" speaker from Polk Audio, IMHO, they are pretty bad. If I don't return them they will probably move from my "listening" room to my garage workshop. I want to say I understand the perception of how good a pair of speakers sound is a very personal thing, and this is just my personal opinion. To my ears, these speakers are simply not as musical as the Totems and old Mirages I own. [ Howard T.  Aug 26, 2014 ]