Infinity Systems Beta 20 Bookshelf Speakers

4.71/5 (7 Reviews) MSRP : $144.00


Product Description

  • 2-Way 6-1/2" Bookshelf Loudspeaker with Patented CMMD Drivers
  • Nominal Impedance: 8 ohms
  • Crossover Frequency: 2,400Hz; 24dB/octave
  • Low-Frequency Driver: 6-1/2" (165mm) CMMD
  • High-Frequency Driver: 1" (25mm) CMMD


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Reviews 1 - 5 (7 Reviews Total) | Next 15

User Reviews

Overall Rating:4
Value Rating:5
Submitted by leadbelly2550 a Audio Enthusiast

Date Reviewed: October 7, 2009

Bottom Line:   
I purchased these speakers to replace a set of Infinity Reference Two bookshelf speakers that were still fine after 18 years of use. I am still breaking them in, so they probably don't yet produce the full accuracy and range of sound they are capable of, but they already sound amazing in my office, just sitting on a carpeted floor, and even better sitting on top of a wood credenza. That's true whether I play Mozart piano sonatas, Miles Davis, Yes, Green Day, Annie Lennox, Living Colour, Radiohead. The highs are accurate without being harsh on my ears, and the mid-low range is solid, tight, not at all "boomy" - yet i can feel it. i figure they will sound even better after they are broken in.

Like virtually all modern two-way bookshelf speakers at this price level, these don't have the deep low end of older, large-woofer speakers. these are more than enough sound for my office or a medium sized room and would undoubtedly be fine in a 20x20 living room as stereo or front channels for a very nice but not bank-breaking surround system. i would recommend a sub-woofer if you are thinking about a 15x15 or larger room, or for people looking for earth-shaking bass for music, home theater or gaming. i have read some people use these as satellites, but they seem a little large for that purpose, and you would need a powerhouse set of front speakers if these are the satellites. they are really a little large and heavy to wall-mount, and they don't have any slots in the back to do that. if you are space-challenged, you may find these (14" high x 13" deep x 9" wide) somewhat bulky.

this is a rear-ported speaker, so it sounds better if you leave some room between the back of the speaker and the wall. the cabinet feels very solid and appears to be engineered wood with a vinyl wood-grain exterior. Mine are black. The grille is metal and solid, so you're not going to damage anything underneath unless you remove the grille - or smack it with a baseball bat, maybe.

to make the most of them - get a receiver that has clean power and a good dynamic range (i happen to like onkyo and harman kardon, but even their low-end receivers are quite good if you don't need lots of bells and whistles) and use good, thick speaker wire. also, keep in mind that while these sound great, higher-resolution sources (CD/DVD) sound better than your ipod.

Infinity does not make these any more, but i found a pair for less than half of the original list price. Don't get hung up on the newest models at this price point - speakers haven't improved that much over the years. as a brand, Infinity speakers have proved to be very reliable for me.

i couldn't be more pleased with the sound - i have heard speakers that don't sound this good at twice the price.

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Used product for:   Less than 1 month

Duration Product Used:   Audio Enthusiast

Product model year:   2005



Overall Rating:5
Value Rating:5
Submitted by dkord a Audio Enthusiast

Date Reviewed: June 30, 2009

Bottom Line:   
Having had the entry-level Primus 152's for a year and impressed with their good sound I wanted to take advantage of the lower internet pricing offered on the Beta 20's and then give them a user review. Infinity has and still uses their C.M.M.D. (Ceramic Metal Matrix Diaphragm) drivers on some higher-end lines on current models and those that preceded the Betas and the company implies that its properties have sonic advantages over other materials when compared to others including woven Kevlar. I have owned three other speakers that used Kevlar, two made by Wharfedale, that being the Diamond 8.2 and the Evo 2-10's which I now have that serve as my reference pair. I wasn't all that happy with the Diamonds since they had some midrange roughness I couldn’t overlook. The Evo's though are very smooth and detailed with a well defined treble and uncolored response top to bottom. I also own the highly regarded Energy RC-10’s which also uses a Kevlar cone and have good things to say of them as well.

The Beta 20's are almost as deep as they are tall which gives them a bit of a chunky appearance when viewed from their sides but their clean looking mounting plates and curved fronts mostly compensate for that. In this case, better deep than tall, since their 13.7 inch height and understated appearance keeps them from dominating the room. Infinity also makes another bookshelf model, the Beta 10, which has a five inch woofer as opposed to the 20's six and a half inch driver. Finish choices are cherry or black-ash vinyl veneer. Since they are rear-ported they are best positioned away from the wall a bit and should be, if possible, stand-mounted rather than placed in an enclosed bookshelf for the flattest response and with each weighing in at 20.5 lbs. good, solid stands are important. With an efficiency rating of 90 dB at 8 ohms impedance, just about any good mass-market stereo or multi-channel receiver should drive them easily.

I placed them about 1.5 ft from the short wall in my 17 X 12 living room, on 24” Wood-Technology stands (heavy metal stands with a 7 inch top-piece would’ve been ideal) and first ran them flat in stereo mode but found that they sounded best when mated with a subwoofer with the receiver's crossover set to 60 Hz which took some of the bass work off the Betas and onto the sub with its crossover set at about 2 o’clock. The result was very satisfying, tight bass. Running them full-range, the bass is not the best I’ve ever heard in a large bookshelf, but certainly not the worst either. One of the first things I did notice was the way the Beta’s handled midrange instruments and voices – very natural and inviting with very good front soundstaging so that the Beta center C-250, which I also own, is really only needed to anchor dialog and effects when watching movies and while the ‘20’s may sound a just tad warmer than some speakers that accentuate the presence region to the point of fatigue, I find it easy to relax into the Beta’s for extended periods with all the types of music that are in my collection. For example, in Gary Burton’s wonderful smooth jazz CD, ‘Cool Nights’ (GRP) Bob James’ keyboards and Burton’s vibraphone solos have both the clarity and body that closely approaches that of my Evo 10 reference pair. The speakers amply fill an average sized listening room so that they do indeed sound big, like small floorstanders and both male and female vocals are warm without sounding husky. To sum up, it seems to me that Infinity’s C.M.M.D. engineers have done their job well with their low-distortion, rich and neutral sounding Beta 20 speakers and I give them my unreserved thumbs-up.

This model has been discontinued and at this time the Harman Store is still selling them at auction as B-stock singles on Ebay and they come with a full factory warrantee. The average selling price as was mentioned by another reviewer, is in the $50.00 range, plus a $20.00 shipping charge per speaker so they’re definitely worth trying out. They can also be found elsewhere on the net where they are heavily discounted.

Happy jams to you all!

Associated Equipment:
Denon AVR-1707 7 Channel Receiver (75 wpc)
Denon DVD-1940CI Player
Boston Acoustics VR-500 Subwoofer
BIC Acoustech HT-63 Surrounds

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Used product for:   1 to 3 months

Duration Product Used:   Audio Enthusiast

Product model year:   2004



Overall Rating:5
Value Rating:5
Submitted by pwned32 a Casual Listener

Date Reviewed: January 30, 2009

Bottom Line:   
MSRP is 200 a piece for these. They can be found for much cheaper online. I bought 2 on ebay re manufactured with full warranty from Harmon audio for about 60 a piece with shipping. I used these to replace a pair of JBL 5" monitor speakers. When i got these i noticed that there easly twice the size of my former JBLs. They are very solid at 20ish pounds a piece. Have the hooked up to a Onkyo TX-8555 stereo receiver and they sound fantastic. they have great clarity even at high volumes and great bass output for 6.5" drivers. You probably will not be mounting these, so you may want to invest in speaker stands. Perfect for a stero setup, rear surround speakers or even front surround speakers. If you can get them for less than 200 a pair, i would consider them a great deal

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Used product for:   1 to 3 months

Duration Product Used:   Casual Listener

Product model year:   2008



Overall Rating:5
Value Rating:5
Submitted by jose vergara a Audio Enthusiast

Date Reviewed: September 6, 2006

Bottom Line:   
HI THERE! I just got these speakers,and let me tell you something.these speakers are well build and they sound wonderful,very clean and deep bass.I had many good speakers like:PSB,CANTON,B&W,KEF,POLK AUDIO,JSE just to mention some of them.these fellas can proudly stand up next to the good speakers.NO DOUT! well done INFINITY.

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Used product for:   Less than 1 month

Duration Product Used:   Audio Enthusiast

Product model year:   2005

Price Paid:    $380.00

Purchased At:   CIRCUIT CITY



Overall Rating:5
Value Rating:4
Submitted by egotmick a Audio Enthusiast

Date Reviewed: May 17, 2006

Bottom Line:   
These are great looking (cherry finish), classic speakers that deliver great sound in this class. Intending to use them with Infinity Beta 50 (for stereo, mainly classic) and C 360 (for home theater). Beta 20 are working also great stand alone.

OK, they are big for the a book shelf speaker. But that's the way a speaker should be, what you loose in space you get back in sound. They are more like "furniture" - in a good way. Except for a few high-end speakers way out of my price range, I have not heard anything good from something small and light. Big is good.

Expand full review >>

Used product for:   Less than 1 month

Duration Product Used:   Audio Enthusiast

Product model year:   2006

Price Paid:    $135.00

Purchased At:   www.acousticsounddes




Reviews 1 - 5 (7 Reviews Total) | Next 15

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Polk Monitor 40 vs. Infinity Beta 20

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