3D Connexion IL120s specifications Review System, Oh yes, the subwoofer, Listening

108-0111-Infin-p074-76,78x 1/24/02 1:32 PM Page 76

I N F I N I T Y S Y S T E M S I N T E R L U D E I L 1 2 0 S

which determines the frequency of the dominant subwoofer/room peak as well as the shape of that peak. You then set the bandwidth control to match the shape of the peak, and attenuate level at the appro- priate frequency by an amount that will pro- duce a flat frequency response. After the equalization process is completed, you can check the results by repeating the test tones and plotting the frequency response again. R.A.B.O.S. can correct for only a single dom- inant peak, but this is said to be the most common subwoofer/room interaction. In situations where there are two significant peaks, the R.A.B.O.S. manual suggests cor- recting the one at the higher frequency, which is likely to be more audible and objectionable. If there are adjacent narrow peaks and dips, the manual says to leave them alone—they’re the result of interfer- ence patterns that are specific to a certain spot in the room, and in any case can’t be corrected by this type of equalization.

76Stereophile Guide to Home Theater • November 2001

Oh yes, the subwoofer . . .

Aside from the R.A.B.O.S. function, the IL120S looks like a fairly conventional pow- ered subwoofer with a rear-facing port that’s flared to reduce turbulence. The IL120S is not one of those newfangled ultra-compact subs, and does not have servo control. How- ever, it does have one high-tech feature: the driver is a special 12-inch unit with a propri- etary Ceramic Metal Matrix Diaphragm (C.M.M.D.) and a 60-oz magnet structure. According to research reported in a white paper on www.infinitysystems.com, loud- speaker cones made of C.M.M.D. have fewer inherent resonances and are capable of more linear pistonic movement than any other comparable material. The effect is said to be the elimination of colorations due to cone modes, which should result in dra- matically reduced distortion.

Amplification is provided by a 500W class-AB amplifier with a cool-running switching power supply. In addition to the R.A.B.O.S. controls, the IL120S includes a

phase-reversal switch and a continuously variable lowpass filter that can be turned off if the subwoofer is used with a Dolby Digital/DTS surround processor-receiver. The IL120S’s sculpted front panel and grille are attractive, and the review sample was finished in “onyx-anigre,” which I take to be a term for a better class of fake wood.

Listening

Before trying to fine-tune the IL120S with R.A.B.O.S., I wanted to check out its raw performance with the R.A.B.O.S. controls turned off completely. I set up the IL120S as per my usual practice: sub placed at front left, just a bit out from the corner, the main speaker/subwoofer balance adjusted using the built-in calibration tones of the Rotel RSP-976 surround preamplifier-proces- sor—or, when using the Thule PR 250B processor (which lacks a subwoofer calibra- tion tone), the test tones on Stereophile’s Test CD 3. To ensure comparability with my previous subwoofer reviews, I used a RadioShack sound-level meter.

Over a period of several weeks, watching familiar DVDs as well as new releases (I rent many more than I buy), the impression that I formed of the IL120S was that, for $899, it’s a competent but unexceptional performer. Extension was good, and there was lots of volume available, but the bass was a bit boomy, lacking some tightness. I played

REVIEW SYSTEM

Sources

Rotel RDV-1080 DVD player

JVC HR-4700U VCR

Surround Preamp-Processors

Rotel RSP-976

Thule PR 250B

Power Amp

Bryston 9B-ST

Speakers

Dunlavy SC-I (5)

Cables

Digital: TARA Labs Decade

Interconnect: assorted AudioQuest

Speaker: AudioQuest Type 6+

Misc.

Chang Lightspeed CLS HT1000 power-line conditioner

AudioPrism QuietLine LF-1 Mk.II parallel power-line filters