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Boston Acoustics M350

Floor-standing speaker

1 Review

Item # 065M350

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Our take on the Boston Acoustics M350

Exceptionally accurate, aesthetically pleasing

The top floor-standing speaker in Boston's M Series, the M350 is a powerhouse specializing in the kind of detailed, spacious sound that brings your music and movies to life. This slender 3-way tower design excels when used as a stereo pair or as front left and right speakers in a multi channel home theater system.  Plus, the M350 looks every bit as good as it sounds. With a glossy black lacquer finish and luxurious leather-feel trim, it makes an elegant addition to just about any space.

Advanced tweeter design for spacious, detailed highs

Boston's Extended Wide Bandwidth tweeter

Boston's Extended Wide Bandwidth dome tweeter lets the M350 really sing with silky, transparent highs. Unlike most tweeters, this one has a dimple in the middle that stabilizes the motion of the tweeter for significantly lower distortion, as well as improved dispersion for a deep, expansive soundstage, and greater clarity over a broad range of frequencies.

A musical midrange with a room of its own

Boston mass-loaded midrange and midrange sub-enclosure

The M350's delightfully musical midrange comes courtesy of the mass-loaded 4-1/2" midrange driver. This uniquely designed cone features four small rectangular “tabs” on the inside edge of the surround that add mass to achieve smoother frequency response at the top of the driver's operating range. This mechanical mass-loading approach eliminates the need to add more electronic components (and complexity) to the crossover, resulting in cleaner sound and superior imaging in the critical upper-midrange frequencies.

Along with its mass-loaded cone, the M350's midrange also gets its own separate internal chamber. This acoustically isolates the midrange from the woofers inside the cabinet to prevent them from interfering with each other and muddying the sound. The separate midrange chamber also doubles as a reinforcing brace near the top of the cabinet to add rigidity and reduce cabinet vibrations even further.

Multiple woofers deliver tight, accurate bass

The M350 delivers precise, hard-hitting bass thanks to its four matched 5-1/4" woofers and and acoustically tuned port. Combined, these four woofers have approximately the same radiating surface area as a single 10” woofer. But by using multiple smaller drivers, the M350's front baffle is kept narrow to improve its sound dispersion into the room and give it a more slender, room-friendly profile. Another advantage to this design is that four separately positioned woofers generate multiple floor reflections (also known as floor bounce). This minimizes the speaker's sensitivity to room placement, for smoother bass response than is typical from a single larger driver. 

Better cabinet construction = better sound

Cabinet vibration, or resonance, is the enemy of clear sound. It distorts and colors the sound of instruments and vocals. Boston's M Series speakers fight vibration with LoQ™ cabinet construction. By using two sheets of MDF (medium density fiberboard) with a special damping adhesive layer between them, Boston created an enclosure that provides the acoustic deadening of much thicker materials without the drawbacks of added weight and increased size. The result is a relatively compact, lightweight speaker that has a very low resonance — or in speaker-speak, a low “Q.”

In addition to the Lo-Q cabinet material, Boston also used a scanning laser vibrometer to critically position the M Series cabinets' internal braces where they provide the most benefit. Then they add heavy-duty absorptive cabinet fill to eliminate internal standing waves. These advanced cabinet building techniques and materials result in speakers with impressive transparency and a large, detailed soundstage.

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Product Highlights:

  • 1" Extended Wide Bandwidth soft dome tweeter for excellent clarity and low distortion
  • 4-1/2" mass-loaded polypropylene midrange provides smooth overall response with minimal coloration
  • four 5-1/4" polypropylene woofers minimize sensitivity to room placement and optimize bass response
  • bass reflex (ported) enclosure
  • separate internal chamber isolates midrange driver from the woofers to prevent interference
  • Boston Lo-Q™ cabinet construction reduces vibration and eliminates unwanted resonance
  • high-gloss black lacquer finish with leatherette trim
  • frequency response: 45-30,000 Hz (±3dB)
  • sensitivity: 90 dB
  • impedance: compatible with 8-ohm outputs
  • recommended amplifier power: 50-500 watts
  • high-quality 5-way binding post speaker terminals
  • 9-5/8"W x 42-3/8"H x 12-1/4"D
  • weight: 55.9 lbs.
  • warranty: 5 years
  • Our 60-day money-back guarantee

Very we'll made speakers sounds amazing they will rock with very high quality

Tim, Ganado

What's in the Box:

  • Floor-standing loudspeaker
  • Detachable grille (installed)
  • 4 Rubber feet (pre-installed)
  • 4 Spiked feet
  • Owner's Manual (En/Fr/Sp)

Boston Acoustics M350 Reviews

Average Customer Review(s):

(1 Review)


Tim from Ganado on 12/22/2013

Crutchfield Customer Review (What's this?)

Very we'll made speakers sounds amazing they will rock with very high quality

Pros: You get what you pay for

Cons: It's cost a lot to have speakers that sound this good


Hands-on research

Features and Specs

Enclosure Bass Reflex
Finish MDF/Leatherette/Lacquer
Color Black
Tweeter Dome
Tweeter Size (inches) 1
Midrange Size (inches) 4.5
Woofer Size (inches) 5.25
Woofer Composition Polypropylene
Woofer Surround Rubber
Built-in Powered Sub No
Video-Shielded No
Connector Type Post
Bi-amp Inputs No
Parts Warranty 5 Years
Labor Warranty 5 Years
Power Range 50-500
Frequency Response 45-30,000 Hz
Sensitivity 90 dB
Impedance (Ohms) 8
Amplifier Power ---
Height (inches) 42-5/16
Width (inches) 9-5/8
Depth (inches) 12-1/4
Weight 55.9 lbs

Product Research


Three-Way Speaker Design: This three-way speaker combines a 1" Extended Wide Bandwidth dome tweeter with a 4.5" midrange and four 5.25" woofers for smooth, natural sound, and dynamic bass. Experience rich sound while enjoying music, movies, and more with the M350 floor-standing loudspeaker from Boston Acoustics.

  • 1" Extended Wide Bandwidth Dome Tweeter: The M350 floor-standing loudspeaker is equipped with Boston's signature 1" Extended Wide Bandwidth (EWB) dome tweeter, which is designed to cover a broad range of frequencies, reduce distortion, and improve clarity in the high registers. Unlike most tweeters, the EWB has a small dimple in the middle and a large radiating surface that extends from the center to the outside perimeter of the diaphragm. This design enables the tweeter to track subtle treble details and reproduce the highest frequencies with ease.
  • 4.5" Midrange Driver: A 4.5" polypropylene midrange employs mass loading to dampen harmful resonances and achieve a smoother frequency response at the top of the driver's range.
  • Quad 5.25" Woofers: The M350 also features an array of four 5.25" polypropylene woofers that produce multiple floor reflections that minimize sensitivity to placement and optimize bass response. The woofers feature aluminum shorting rings for dramatically lower distortion and a clearer sound.

High Quality Crossover Networks: Very high quality crossover networks featuring low loss film capacitors and low distortion laminated silicon steel core inductors are utilized for greater clarity and minimal coloration.

Lo-Q Cabinet Construction: The M350's Lo-Q cabinet is built to reduce vibrations and eliminate unwanted resonances. The M350 has a cabinet made of Lo-Q, a material consisting of two pieces of medium-density fiberboard joined together with a thick layer of damping adhesive in the middle. This material significantly reduces cabinet vibrations to virtually eliminate unwanted resonances allowing the M350 to create a larger, more vivid soundstage. The cabinet also contains heavy-duty absorptive fill and internal braces which have been strategically positioned to maximize the speaker's strength and optimize sound.

Isolated Chambers: An internal chamber acoustically isolates the midrange from the woofers to prevent interference and serves as a reinforcing brace near the top of the cabinet to add rigidity and reduce vibrations even further.

Gloss Black Finish w/ Leatherette Wrap: The M350's gloss black finish and curved side panels with faux leather wrap can complement almost any decor.

Rear-Firing Port: The Boston Acoustics M350 employs a rear-firing port for higher efficiency and greater bass response. Because of the rear-firing port, the speaker should be placed at least 3" from the wall.

Binding Post Speaker Terminals: The Boston Acoustics M350 floor-standing loudspeaker is fitted with a set of binding post speaker terminals that will accept bare wire (up to 10AWG), banana plugs (single only), spade-connectors, and pin-connectors.

Rubber & Spike Feet: The M350 floor-standing loudspeaker comes with pre-installed rubber feet which are ideal for hardwood floors. Spike feet are also included for placement on a carpeted surface.

Our Product Research Team

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