Back in hi-fi’s golden age, there used to be hot debates over “East Coast” vs. “West Coast” sound — no doubt a tame forerunner of the hip-hop wars of the ’90s. East Coast speakers were thought to be smooth and mellow, with “concert-hall” sound best suited to classical music and jazz. West Coast models were bright and punchy — just the ticket for loud rock & roll.

Of course, this was largely bunk. There were plenty of “hot” speakers made back east and lots of smooth California models. For its part, Infinity Systems of Chatsworth, California, always avoided the labels and got on with the business of simply making excellent speakers, including some of the more innovative (and expensive) designs ever sold.

Infinity’s new Beta speaker line is priced squarely in home theater’s upper-middle-class. The suite we put together included the larger of two bookshelf models, the Beta 20, for the front left/right positions, the Beta C250 center speaker, a pair of Beta ES250 surround speakers, and the unusually powerful and compact CSW-10 subwoofer.

PDF: Fast Facts

For this report, I placed the Beta 20s on stands, the C250 atop my 30-inch widescreen HDTV, and the ES250s on my usual high, side-wall shelves — the same positions normally occupied by my reference speakers. I put the CSW-10 in my tried-and-true subwoofer spot, a bit to the left and behind the left front speaker.

Though small in size, the CSW-10 is a big part of this system’s story. Inside this modest but surprisingly heavy cube are a single 10-inch driver, a 650-watt BASH amp (one of today’s super-efficient “smart” amplifier topologies), and Infinity’s Room Adaptive Bass Optimization System (RABOS). Besides the three knob controls on the sub itself, RABOS comprises a test CD, a sound-level meter, some “audio-log” graph paper, and a special ruler to help you calibrate the system. All of this is intended to help you get the best possible sound in your room. Here’s how it works:

With the meter at your listening position, you balance speaker levels, then play test tones on the CD and plot the meter readings on the graph paper. The result is a graph of the subwoofer’s frequency response. Then you overlay the ruler on the graph to find how to set the sub’s Level, Width, and Frequency controls for optimal bass performance.

Once set up and tweaked, the Beta system proved to be a solid performer. With stereo music, the Beta 20s (played alone)had a notably extended, detailed, yet smooth treble — in a word, they sounded “sweet.” The midrange was scrupulously defined and clean, though with a touch of leanness through the male vocal regions. These small speakers also put out enough bass to keep me happy with most music.

In my standard movie-sound torture tests, the complete system played loud, with enough bass impact for any soundtrack. Seabiscuit is one of those films whose soundtrack, though unspectacular, serves its story well with its wide range of voices, music, and sound effects. Its horse-race sequences thundered by in a way that put me at the track — had there been a $2 window, I’d have placed a bet.

The C250 center speaker delivered even, clear response on the full range of dialogue and TV-announcer voices, with very little coloration. And I heard less change in the midrange tones as I moved off-center than with many other horizontally oriented two-way center speakers. However, I also discovered that the Infinity center’s tweeter has a fairly tightly controlled spread. If I moved more than a little to either side — to the far end of a sofa, say — I noticed some falloff in snap and sparkle, even to the extent that some voices sounded smoother than at dead center.

The Infinity array vaulted my multichannel music hurdles with unified, clean playback from the best recordings. For example, James Taylor’s SACD October Road is a sparkling six-channel studio production, and the Betas let me hear every bit of it. Tracks like “Raised Up Family” maintained all the superb clarity and instrumental definition I expected, and the disc was an excellent test of the ES250 surround speakers’ three different modes.

PLUS Very accurate, well-balanced sound. Deep bass from a small sub. RABOS improves bass performance. Highly flexible surround speakers. MINUS Center speaker loses some treble snap and sparkle when heard off to the sides.

A three-way toggle switch on the middle panel of the trapezoidal cabinet selects bipole, dipole, or monopole mode. In bipole mode, the ES250’s dual driver arrays, each with a woofer and a tweeter, operate together, in phase. Dipole mode throws them out of phase (one set pulling inward as the other pushes out), producing a “null” directly in front, which enhances ambience and reduces the ear’s ability to locate the speaker. Monopole mode silences one array altogether, yielding a simple two-way speaker.

Monopole mode provided the smoothest tonal match with the front speakers, especially on multichannel discs like the Taylor SACD, lending the most believability to the horn-stabs and percussion flourishes in the surround channels. Bipole mode added low-midrange oomph, but it was on the heavy side. I preferred the Dipole mode for movie soundtracks because it dramatically improved envelopment, but it sounded a bit hollow on this kind of music recording.

Unfortunately, as with nearly all such designs, you have to switch each speaker manually to change operating modes. Die-hard surround enthusiasts will be pleased to know that the ES250’s two driver arrays can be individually wired, so you can use a single speaker as a back surround and feed it both left and right back surround signals in a 7.1-channel setup.

Heard over the Infinity Beta system, the horse-race sequences in Seabiscuit thundered by in a way that put me in the grandstand.

The CSW-10 sub’s RABOS controls include a defeat switch, so once you have them set, you can easily turn the system on and off to judge its effects. With it engaged, the bass was subtly fuller on a lot of music and sounded slightly more powerful in the lowest octave, but without the added pounding that would come from simply raising the volume. For example, the thunder of thoroughbred hooves in the race sequence from Chapter 19 in Seabiscuit was a shade thuddier with RABOS engaged without sounding boomy.

In the final analysis, the Infinity Beta is a well-balanced and excellent-sounding system that neatly splits the difference between “speakers for music” and “speakers for movies.” That leaves one unanswered question: with corporate headquarters now in New York but its design center in California, is Infinity a West Coast or an East Coast brand?

PDF: In the Lab