I'm old enough to remember the era when loudspeakers were particleboard tombstones that came only in pairs. With years and years of surround-speaker reviews under my belt, I look back to those times and laugh. Nowadays my editors literally couldn't pay me to assemble a surround system from floor-standing speakers. I'll make an exception for a system anchored by a good pair of powered towers, but rarely, very rarely. My reference speakers are bookshelf-sized (although I use them on stands, of course), and that's the type of speaker I specialize in reviewing. Bass is something I get out of a subwoofer. What I want my satellite speakers to deliver is a big, open, versatile midrange with a garnish of high-frequency extension.

Pinnacle Speakers is not a company that’s caught up in the bigger-is-better game, which probably reduces their products appeal to adolescents, as well as to adults stuck in adolescence. However, president and chief engineer Rich Rothenberg and his brother Mike in marketing have spent 30 years refining their company's product line to eliminate the stupid and the unsubtle. There is a Pinnacle product in my collection -- the Baby Boomer subwoofer -- and it got there because I sought out a small sub, solicited recommendations from a former editor-in-chief of this magazine, and bought it. However the subject of this review is the Pinnacle Quantum surround speaker system and the SubSonic sub.

Experience has taught me that the cleanest-sounding speakers eliminate resonance with either the enclosure’s internal bracing or the use of a totally different material than the customary medium-density particleboard (such as molded plastic or metal). The Quantum does both, with a braced, diecast aluminum chassis. Each sleek grey speaker has a pair of carbon-graphite cone woofers (with rubber surrounds) that flank a liquid-cooled titanium tweeter. All tweeters have a break-up mode where they over-modulate and lose accuracy, and titanium’s break-up mode can sound especially nasty. According to Pinnacle’s website, to tame this, the Quantum satellite employs "a special patented process known as Cathodic Arc Evaporation, which provides a protective plasma vapor coating to the titanium diaphragm." This process gives the tweeter its "pleasing purple hue."

Each satellite is 9.32 inches high by 3.75 wide by 7.375 deep and weighs 5 pounds. It is, of course, magnetically shielded to prevent discoloration of a nearby screen. The two-way, three-driver design isn’t vented, which makes the Quantum an acoustic-suspension speaker in the tradition of the late Henry Kloss. Power handling is 15-100 Watts (although Pinnacle recommends at least 20 Watts), so the Quantums would make good replacement speakers for a lesser-quality HTIB system, or at least one that’s powerful enough to drive a speaker with an 86-dB sensitivity (nominal impedance is 8 Ohms). The speaker terminals are slim, gold-plated binding posts. Pricing is $250 per speaker in packages of two or three. The SubSonic sub goes for $699, and the whole 5.1-channel system costs $1,699.

Even smaller than the Baby Boomer subwoofer, the SubSonic packs two 6.5-inch woofers into each side of a 7.875-inch enclosure with metal-cone feet (versus the Baby Boomer's twin eight-inch woofers in an enclosure that’s two inches larger). The internal amp is rated at 350 Watts. Heat fins jut out of one side, which also includes a 50-150Hz crossover dial, 0-180 degree phase switch, and a volume control. I set the volume control at 40 percent up, just as I do with larger subs. There's also a crossover bypass switch, something every sub should have but not all do. This switch lets the user select a crossover setting in their surround processor without having the signal pass through a second, superfluous crossover circuit in the sub. I switched the crossover off. Since the speakers are rated at 100 Hz to 21 kHz, I went into the surround processor's menus and selected a crossover of 100 Hz, which is a bit higher than my usual preference of 80Hz--a move that would take on greater significance later.

The Quantum is wall-mountable (hardware included) and has a short pedestal that allows for horizontal or vertical positioning. Built into each speaker, the pedestal can also tilt the speaker upward, an option I used for the front left and right speakers, which are a couple of inches lower than the center in my system. I strongly suggest that you use vertical positioning for all sats -- yes, including the center speaker -- to avoid the comb-filtering peaks and notches that sometimes result from dual-woofer designs. You can pivot the logo so that you needn’t look at it sideways.

All vertical placement is what I chose when I connected the satellites to Rotel's beautifully dynamic RSX-1065 surround receiver. Signal sources included a Pioneer DV-37 DVD player and Marantz DR6050 CD recorder. Although I moved my reference speakers--a 7.1-channel set of the Paradigm Studio/20 with the PW-2200 12-inch sub-- to the side of the room, they were strongly present in spirit, like the lover you can't forget while you're with the one you have. I've only recently adopted the Paradigms as my reference speakers, but everything I review from now on I will either compare with them (other speakers) or use with them (other components).

The speakers arrived on a chilly day, so I let them sit overnight and warm up (literally) before beginning my critical listening. To get a sense of how they sounded without the sub, I told the Rotel surround processor to run them full-range, an experiment that lasted all of 30 seconds. With a bottom end of 100 Hz, these speakers have no lower or mid-bass and not a whole lot of upper bass, either. After I quickly reset the processor for small speakers and switching on the sub, I started running through test tracks.

Vocal snares on my test disc include the voices of Sandy Denny, which takes on a steely edge at peak moments, and Bill Morrissey, who can sound chesty when moving into his lowest octave. The Quantums aced Denny's "The Banks of the Nile" (from the Fotheringay CD) while also revealing the precise distance of her drummer's cymbals from the mic. Morrissey's voice ("Time to Go Home," Night Train) did jump from the center speaker to the sub, but that's inevitable with a 100 Hz crossover. To my surprise the effect didn't recur when I tried the title track of Nick Drake's Pink Moon. With a high crossover, when Drake sings, "Pink, pink, pink, pink ... pink moon" I usually hear the leading consonant popping out of the sub. Not this time. The Pinnacles kept Nick in one piece. Most impressive. With all of the singers, I also got a strong sense of dynamic shadings, as their heads bobbed in front of the microphone.

The SubSonic is rated at -3 dB at 28 Hz, so it missing no more than a few notes in the bottom octave. I wanted to hear it with Danny Thompson's string bass on "The May Day Psalter," recorded with Richard Thompson for the Circle Dance compilation. It sounded close to perfect. Most subs this size (especially those packaged with micro-systems) flunk the string-bass test because they're basically one-note boxes that cannot carry a series of coherent pitches. The SubSonic delivered all the pitches, in their natural proportions, and gave me a good sense of the touch on each string. The cello introduction to Piazolla's "Fuga 9" (for string quartet, Mr. McFall's Chamber, Like the Milk) was similarly smooth and proportionate.

By the time the Quantums started peeling the layers off "The Painbirds" by Sparklehorse (Good Morning Spider) I was so wowed that my notebook started filling up with exclamation points. The titanium tweeters were strong enough to illuminate the subliminal parts of Duane Allman's playing on "Key to the Highway" by Derek & the Dominoes -- not just the solos, but also the sotto-voce bits where he's quietly diddling the rhythm guitar part and letting Eric Clapton be Eric Clapton. I wrote in my notebook: "Feels so good!" By the time the CD-R finished up with The Who, Metallica, and Mountain, I was playing the system loud and loving it.

By the way, I do most of my music listening these days in Dolby Pro Logic II. On the rare occasions when I switched to stereo, the Quantums more than held their own. I also fooled around with a 5.1-channel version of DTS Neo:6 with the back channel shut down. They all sounded good.

One of my DVD rentals was Anatomy, a German thriller about med students who dissect live patients ("The subject is you!"). In standard horror-movie fashion, the surround channels filled up with music and effects at peak moments, then the mix dwindled to front-and-center for quieter dialogue passages. Speaking voices were natural, and the swelling gothic orchestra bleats filled the room.

Now comes the difficult moment where I compare the Quantums with my Paradigm Studio/20 reference speakers. Both have the big, open, versatile midrange that I alluded to earlier. However, in terms of inner detail the Paradigms have the advantage. Both have a strong top end that may get nasty with cheap, dirty amplification, but they just sing with an above-average receiver like the Rotel. My Paradigm PW-2200 sub, with 12 inches of woofer, surpasses the SubSonic in bass extension, slam, and volume capability. However, the SubSonic can do a good 85 percent of what the Paradigm sub can do, with nearly the same control. What blew me away was the tight, nearly seamless integration of the Quantums and SubSonic. It’s remarkable, especially considering that the Quantums require the SubSonic to operate with a 100 Hz crossover. Normally, forcing a sub to produce so much upper bass would invite stress and congestion, but not with the SubSonic.

The Quantums were virtually free of cabinet resonance and coloration. Rap them with knuckles, and you'll hear a very short decay. I made my knuckles sore repeating this test to be sure. The Quantums are also tiny enough to reduce acoustic diffraction to an absolute minimum. In this respect, big speakers are their own worst enemies.

In the final analysis, the real competitors of the Pinnacle Quantum and SubSonic are not my Paradigms but the likes of the Acoustic Research HC6, Bose AM-5, and Energy Take 5.2. Judged against that competition, the Pinnacles kick butt and kick it real hard. They are not merely, as the old saying goes, "competitive in their category." They sit smack on top of it and no one else comes close. If you want small, wall mountable satellites, as well as excellent tonal balance and highly musical bass from a sub that’s half the size of a seated cat, the Pinnacle Quantum/SubSonic system is precisely what you've been looking for. It’s arguably the best set of mini-satellites and the deepest-voiced baby sub sold today. Memo to the Rothenbergs: If you’ve got a piece of SubSonic B-stock for my collection--maybe a cosmetically damaged piece that you can’t sell--I’d be honored to give it a home.