Infinity Beta 40

Floor-standing speaker

  • Infinity Beta™ 40


  • Infinity Beta™ 40


  • Infinity Beta™ 40

Item #: 108BT40B

Review Summary

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Our take on the Infinity Beta™ 40

by Loren Barstow

Floor-standing speakers — still standing tall

Sure, floor-standing tower speakers buck the industry trend toward smaller, visually inconspicuous speakers, but they're hard to beat if great sound is your primary goal. Tower speakers produce powerful sound with excellent bass, making them a great choice for serious music lovers and for folks who want high-impact home theater.

Music and movie lovers will find a lot to like in Infinity's Beta 40. This slender tower speaker uses Infinity's most advanced drivers to produce a wide soundstage and precise imaging. Its solid MDF cabinet houses a 1" tweeter, a 5" midrange, and dual 6-1/2" woofers. You'll enjoy detailed, accurate highs and mids plus distinct, musical bass.

This speaker owes its open, natural sound to Infinity's patented Ceramic Metal Matrix Diaphragm driver material — the same material Infinity uses in their top-of-the-line models. CMMD™ combines layers of ceramic with a stiff metal core for crystal-clear sonic performance. It's strong and durable, yet incredibly lightweight and responsive.

All the speakers in Infinity's Beta Series are voice-matched for consistent sound. This makes it easy to assemble a home theater system to fit your needs and preferences.

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  • sold individually
  • video-shielded
  • bass-reflex (ported) enclosure
  • frequency response 45-20,000 Hz (±3dB)
  • 8-ohm impedance
  • sensitivity 91 dB
  • handles up to 200 watts
  • 3-way design
  • 1" CMMD tweeter
  • 5" CMMD midrange driver
  • dual 6-1/2" CMMD woofers
  • two sets of 5-way binding posts for bi-wiring
  • 8-7/8"W x 38-5/16"H x 13-3/8"D
  • warranty: 5 years
  • Our 60-day money-back guarantee
Priced each

    Hands-on research from the Crutchfield Labs (what are the Labs?)

    Features and Specs
    Enclosure Bass Reflex
    Finish Wood grain vinyl
    Color Black
    Tweeter Dome
    Tweeter Size (inches) 1
    Midrange Size (inches) 5
    Woofer Size (inches) 6.5
    Woofer Composition CMMD
    Woofer Surround Rubber
    Built-in Powered Sub No
    Video-Shielded Yes
    Connector Type 5-Way post
    Bi-amp Inputs Yes
    Parts Warranty 5 Years
    Labor Warranty 5 Years
    Power Range 10-200
    Frequency Response 45-20k Hz
    Sensitivity 91 dB
    Impedance (Ohms) 8
    Amplifier Power ---
    Height (inches) ---
    Width (inches) ---
    Depth (inches) ---
    Weight ---
    Product Research
    What's in the box?

    Download owner's manual

    • 1 Floor-standing Beta 40 speaker
    • Removable grille
    • 4 Spiked feet
    • Owner's Guide (English/French/Spanish/Dutch/German/Italian)
    • Limited Warranty sheet

    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 open the box, verify contents, 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.


    Overview: The Infinity Beta 40 is a 3-way, dual 6-1/2" floor-standing loudspeaker featuring Infinity's patented CMMD drivers.

    Ceramic Metal Matrix Diaphragm (C.M.M.D.): Infinity's C.M.M.D. technology delivers accurate performance with dramatically reduced distortion for incredibly lifelike sound. Additionally, the C.M.M.D. drivers can withstand extreme temperatures, moisture, humidity and sunlight.

    Woofers: The dual 6-1/2" C.M.M.D. cone woofers virtually eliminate coloration due to cone flexing, resulting in less distortion and superior accuracy. For a smoother response and improved durability, each woofer uses a rubber surround.

    Midranges: The speaker use a 5" C.M.M.D. cone midrange for increased vocal and midrange clarity.

    Tweeters: Each speaker has a 1" C.M.M.D. dome tweeter, which offers superior stiffness and damping compared to traditional metal domes.

    Constant Acoustical Impedance Waveguide (CAI): The 1" C.M.M.D dome tweeters are mounted in a Constant Acoustical Impedance Waveguide for improved high-frequency dispersion anywhere in your listening room. The CAI Waveguide design is ideal for both stereo or multi-channel applications.

    Bass Reflex: There is a single port tube opening on the rear of each speaker's rigid, well-braced enclosure for increased and extended bass response. Generally, bass output will increase as the speaker is moved closer to a wall or corner due to its rear port.

    Dual 5-Way Binding Posts: Each speaker has two sets of gold-plated 5-way binding posts connected by gold-plated jumpers. By removing the jumpers, you can separately use the two sets of binding posts to bi-amp or bi-wire the speakers. Bi-wiring will improve resolution and dynamics. For even greater improvement, you can use two amplifiers (bi-amping).

    Rubber and Spiked Feet: The speakers feature four non-removable rubber feet that enable the speakers to be placed on a smooth-surfaced floor, such as tile or hardwood. Each speaker also comes with 4 metal spiked feet. The spikes can be used to stabilize the speakers to floor surfaces such as carpet, and they help provide better defined bass response by coupling the speakers to the floor. The spiked feet screw into threaded sockets on the bottom of the cabinet's rubber feet. The spikes add a half inch to the speaker's overall height.

    Magnetically Shielded: The Beta 40 speakers are magnetically shielded for safe placement adjacent to your television.

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    Infinity Beta™ 40 Reviews

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    5 out of 5

    Excellent All Around Front Channels

    Written By xlr8, Dallas, TX on Thursday, January 10, 2008
    Great speakers for a beginner home theater on a budget. The difference between my old Yamaha's and these is black and white, and the mid and highs are superb. Bass quality is good, but i have them set to 'small' becuase i have an awesome infinity ps-12 subwoofer that handles the low end completely by itself.

    The enclosure is high quality and thick, and the speakers are very heavy. The sound is noticibly better when running bi-amp, and the grills are high quality, sturdy metal. I cannot tell if they affect sound quality or not, so i leave them on becuase I like their look.

    By far the best feature is the mid and high, but I think i need to get the c360 center channel. My old Primus is somewhat lacking now that my soundstage has widened so much.

    I have nothing bad to say about these speakers, and they are a steal for the price. You cannot go wrong with these speakers (unless you want a small, slim profile setup, in which case these should be crossed off your list. they have very deep enclosures).
    38 out of 39 people found this helpful
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    For a more in-depth review and enhanced detailed information on the Infinity Beta™ 40, please visit the Crutchfield website product page (/ISEO-rccbcspd/p_108BT40B/Infinity-Beta-40.html ).