The inclusion of a center channel is easily the most intriguing aspect of modern home theater systems. Like a topnotch NBA team -- perhaps a team with someone named Hakeem in the middle a high- performance entertainment system with strength at the center position truly excels by delivering excellent sound quality for multiple listeners and listening position.
Classic two channel stereo has a tightly defined sweet spot, typically limited to only one or two seals, because it relics on a phantom center image. Accurate positioning of sounds between the main speakers can be maintained only as long as the listener remains centered between the left and right speakers. Since the most important information is usually smack in the middle of the stereo image, that's a significant limitation.
The center channel in a home theater system supplies a "hard" source for that information, keeping it locked in place even when the listener chooses a chair well off the center line. (It also improves the tonal balance of centered sounds by eliminating the lower-treble cancellation notch characteristic of phantom-center stereo reproduction.) Once released from the curse of sweet-spot listening. It’s hard to go back.
The center channel speaker carries a heavy performance burden, however. It must cover a wide radiating area, encompassing all seats in the room and because it will carry most of the dialogue and solo vocals it must provide high sound quality. Further, because it will be placed near the TV screen, it must be magnetically shielded to prevent video interference with direct view sets. And it helps if the speaker is small and attractive (especially for use with the popular 27 inch screens).
Fortunately, manufacturers have been hard at work on the problem, as witness the collection of center speakers assembled for this review. All are designed to fit into a home theater over or under the TV screen. They are all magnetically shielded to prevent color interference even when placed directly on a television. They all deliver good sound quality. And most of them are small and good looking.
The performance goals of all good speakers are pretty much the same. We would like smooth response and high output capability at all listening angles over the bandwidth the speakers will be required to reproduce. Since virtually all home theater systems provide bass-management functions to divert the power-hungry low bass (below around 100 Hz) to the front left and right speakers or a subwoofer, the center speaker normally has to work only from the upper bass or lower midrange on up. It must, however, deliver the goods evenly over a wide horizontal angle to reach seats that may be 45 degrees off to the sides. That means the best center speakers will produce smooth response over a 90-degree arc in front of the screen a Herculean task for any speaker.
Test Procedure
To evaluate the speakers in this group I installed each one atop a 51-inch rear-projection TV set in my home theater system and drove it with a 250-watt power amplifier. That placed the center of the speaker baffle approximately 52 inches above the floor, about 42½ inches out from and centered on the short wall of a 12 x 22¼ foot listening room with an 8-foot ceiling. This placement met the installation specifications for all the speakers tested.
I then made in-room frequency-response measurements at a height of 37 inches, approximately matching a seated listener's ear height, and 2 meters from the speaker at angles matching those of three primary listening positions in my room: dead center, as in the middle of the main listening couch, approximately 30 degrees off center at the right end of the same couch, and 45 degrees off to the right in a wing chair. The last position serves as a torture test to separate the merely excellent speakers from the world class ones, but it is nonetheless a real seating position. The measurements do reflect the acoustical influences of my living room and the TV screen, but they are indicative of what you might expect in a typical system. If a speaker is placed against a wall, low-frequency response will be somewhat more extended than what I measured.
Then I listened, hard, at each of the three main positions. Using a set of specially prepared voice and music tracks, movie soundtracks, and pink noise, I checked out each speaker's ability to deliver flat, clean, detailed sound from the midrange up, paying special attention to male and female voices and the speaker's ability to project a sense of space or depth around the performers.
Each speaker was evaluated individually and compared directly with an anchor speaker, a high-performance two-way bookshelf speaker with an 8 inch woofer, mounted on a stand slightly to the left of the TV and aimed to provide a high-quality sonic bench mark at each listening position. The anchor is an excellent main or center-channel speaker in its own right, but its vertical orientation and height disqualify it for center duty in most surround-sound applications.
Program material included the campfire scene from Indiana Jones and the Temple of Doom; an anechoic re cording of a familiar male voice; four popular-music tracks with familiar and well-recorded female vocals (solo and with backup singers) accompanied by acoustic and electric instruments; a jazz trio of acoustic piano, drums, and bass; a big band; and full-bandwidth pink noise. If a center speaker can realistically reproduce acoustic instruments and vocals it will excel for both movies and music.
Finally, playing a popular recording with electric bass, I slowly increased the input to each speaker to a level that would cause audible distress from the anchor speaker's woofer. Although I wouldn't normally expect a center speaker to handle full-range bass, this test told me whether the speaker would be able to handle overload levels grace fully (noiselessly), whether a user could consider using it in Dolby Pro Logic's full-range Wide center-channel mode, and whether it was suited for systems with mini-speaker mains.
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ADS AVF 144
ENCLOSURE: matte-black aluminum with perforated metal grille; sealed
DRIVER COMPLEMENT: two 4-inch copolymer woofers flanking a 1-inch copolymer-dome tweeter response, 70Hz to 23 kHz ±3 dB;
SPECIFICATIONS: frequency sensitivity, 89 dB SPL; impedance, 8 ohms; crossover, 18 dB per octave at 2.5 kHz; recommended amplifier power, 10 to 100 watts
DIMENSIONS: 13 x 4½ x 61/s inches without bracket, 14 x 5¼ x 6½ inches with bracket (W x H x D) WEIGHT: 7½ pounds
WARRANTY: 3 years
PRICE: $449
MANUFACTURER: ADS, Dept. SR, One Progress Way, Wilmington, MA 01887
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KEF MODEL 100
ENCLOSURE: gray; ported
DRIVER COMPLEMENT: 6½-inch woofer with coincident-mounted 1-inch fluid-cooled dome tweeter
SPECIFICATIONS: bandwidth, 70 Hz to 20 khz; sensitivity, 90 dB SPL; impedance, 6 ohms; crossover, 3 kHz; maximum output, 111 dB SPL; recommended amplifier power, 25 to 175 watts into 4 ohms.
DIMENSIONS: 18½ x 6 x 6 inches (W x H x D)
WEIGHT: 11½ pounds
WARRANTY: 5 years PRICE: $500
MANUFACTURER: KEF, Dept. SR, 89 Doug Brown Way, Holliston, MA 01746
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The Contestants
Dedicated center-channel speakers mostly come in one basic style--flat and wide to fit on top of a TV screen. The driver complement is typically a (4, 5 1/4, or 6½ inch) flanking a tweeter pair of horizontally arrayed woofers (or sometimes two). The usual problem with such a driver layout is a tendency for response anomalies to be come evident as the listener moves off the forward axis, anomalies brought on by dispersion limitations or interference between the outputs of the two woofers. As a result, the speaker may sound great from the couch but not so good from seats off to the sides. The extent to which such anomalies are avoided or overcome is a good index of the designer's skill.
In fact, past comparisons I've con ducted with such speakers have almost always revealed steadily deteriorating, if not downright awful, sound at extreme off-center seats. I was, there fore, pleasantly surprised to find that all of the seven speakers with horizon tally arrayed drivers evaluated here maintained consistent sound quality over a ±30-degree arc, providing the same sound to all of the couch seats, and even the compromises evident at the more extreme positions were man- aged in a way that minimized their sonic impact. This shows that manufacturers have been improving their designs over the past couple of years.
Another way to address the need for wide horizontal dispersion is through coincident or coaxial driver mounting.
In a two-way coincident driver the tweeter is mounted at the center of the woofer cone where the dust cap would normally be located. Theoretically, launching all the sound from a single (coincident) point in space avoids the interference effects that typically occur with multiple spaced drivers, yielding uniform radiation in all directions.
Two of the speakers in this group, from KEF and Vandersteen, use coincident drivers with excellent results.
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MARTIN-LOGAN, ELECTROSTATICALLY SPEAKING
If you're a company that specializes in electrostatic loudspeakers -- traditionally large, vertical panels -- what do you do about home theater? In particular, what do you do for a center-channel speaker? How do you match the performance characteristics of your other speakers in a package that will integrate gracefully with a TV screen? One answer (the only one we know of, in fact) is the Martin-Logan Logos, which combines a pair of horizontally deployed electrostatic panels with a cone woofer and a dome tweeter. The result is an exotic, complex, and expensive loudspeaker with radically distinctive styling - a center speaker geared for those who refuse to walk with the crowd! You know the Logos is something special the instant you lay eyes on it. First, it is huge by center-speaker standards -62 pounds, 40 1/2 inches wide, 11 inches high, and 9 1/2 inches deep. Second, it is a three-way speaker employing a 6 cone woofer (similar to the one used in the company's Stylos speaker), two 17 x 9 curved electrostatic midrange panels, and a 1 titanium-dome tweeter. Finally, there's the price tag: $1,750. Not outrageous by the standards of its breed, but well above the prices customary for conventional center-channel speakers.
Inner works include a curved-fascia support structure that holds the twin electrostatic panels, which are mounted on either side of its face. The tweeter is centrally mounted between the electrostatic midrange panels, while the woofer resides in a sealed cabinet formed behind the curved face as an integral part of the enclosure, The enclosure itself fits into a heavy steel mounting bracket with a machine bolt and bushing at each end. The Logos is adjusted vertically to aim directly at the listening position and then secured in that orientation by tightening the machine bolts with a supplied Allen wrench. The bracket is designed so that the Logos can be placed on a TV set or shelf or, if you prefer, mounted on the floor or a wall. Be careful, however, about securing a 62-pound speaker to drywall on 16-inch studs with a bracket that has mounting holes 19 inches apart.
The Logos comes packaged with spikes, rubber feet, and screw-in drywall adaptors for wall mounting. You also need a nearby AC outlet, since the electrostatic panels require a polarizing voltage, The Logos exhibited a fairly constant radiation pattern established primarily by the two electrostatic panels, which operate between 300 Hz and 3.5 kHz. That means roughly a ±5.5- to ±6-dB envelope from 92 Hz to 16 kHz at all operating angles.
Response dropped off at 3 dB per octave below 500 Hz, and an interference pattern around the 3.5-kHz crossover at couch-end angles was joined by another at 1.5 kHz at the 45-degree wing-seat angle.
The Logos sounded rather hollow directly on-axis. Voices were intelligible but colored, percussion jangly, and the spatial presentation pinched and narrow. Moving to the sides, off-axis, ameliorated the colorations, however: Voices became fairly neutral, and the speaker opened up spatially, though the center image tended to shift with the listener. That worked okay for the couch seats, just causing the main sound image to center up directly in front of the listener instead of perfectly middle-screen. Heard from the wing seats, though, a center soloist moved with the listener toward the near-side main speaker, making the soundstage lopsided.
The Logos had excellent sensitivity for an electrostatically based speaker, clocking in at 89 dB SPL. The woofer cone bottomed loudly when fed high-level electric bass, however. Use Pro Logic's Narrow mode with these babies. Low-frequency resonance for the sealed-box woofer was at 56 Hz, and the system reached its minimum impedance of 2.8 ohms at 2.9 kHz, just at the upper end of the electrostatic panels' operating range.
Like an exotic car, the Martin-Logan Logos is a product suited pretty much exclusively to enthusiasts -- people who will appreciate it for what it is and be prepared to accept or work around its quirks and eccentricities in order to enjoy its strengths. Anyone with electrostatic main speakers already probably fits in that category, however, especially if he is contemplating a home theater built around them. Properly set up, the Logos can sound very good provided you're willing to accept a relatively small range of listening positions.
And among dedicated center-channel speakers, it is probably the best match available for Martin-Logan's other speakers (all electrostatics or hybrids like the Logos).
For electrostat buffs making the move to home theater, the Logos fills a void.
Martin-Logan, Dept. SR, P.O. Box 707, Lawrence, KS 66044
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NHT VS-2
ENCLOSURE: gloss-black with removable black cloth grille; sealed
DRIVER COMPLEMENT: two 5¼-inch woofers flanking a 1-inch fluid-cooled soft-dome tweeter
SPECIFICATIONS: frequency response, 75 Hz to 21 kHz; sensitivity, 88 db SPL; impedance, 8 ohms nominal, 4 ohms mimmum; crossover, 2.3khz
DIMENSIONS: 19 x 7 3/4 X 8 inches (W x H x D)
WEIGHT: 17 pounds
WARRANTY: 5 years PRICE: $450
MANUFACTURER: NHT, Dept. SR, Getty Ct., Bldg. A, Benicia, CA 94510
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ADS AFV 144
The ADS Audio Video Focus 144 is an unusually compact acoustic-suspension center speaker with horizon-tally deployed drivers. It comes with a C-bracket that can be used as an adjustable stand or for wall or ceiling mounting. Amplifier connections are via five-way binding posts.
Ergonomically, the AVF 144 led the pack. The stylish little speaker was easily liftable with one hand, and its stand/bracket enables you to position it and direct its output optimally for virtually any installation.
The AVF 144's measured in room response was quite good directly in front of the speaker, with a bandwidth of 100 Hz to 20 kHz tucked inside a ±5-dB window. There was a crossover notch centered at 4 kHz that actually narrowed slightly at 30 degrees off axis. The wing seat, however, was greeted by a wide trough from 600 Hz to 2 kHz, and the tweeter was pretty much out of the picture at that angle by 10 kHz. Measured sensitivity was a little lower than usual for this group at 86 dB. The system's low-frequency resonance was at 102 Hz, and the minimum impedance was 6 ohms at 5.9 kHz. We would agree with ADS's overall impedance rating of 8 ohms.
Sonically the AVF 144 did a work manlike job on dialogue and vocals from all couch positions, limited mainly by a sound field tightly bound to the enclosure. Spectrally, the system had limited body and was a little hot sounding overall. At the wing position, the overall tonal balance retained its hot character, but vocals were still remarkably natural. The speaker's tiny woofers crackled with pain when driven hard, so it should be used with Pro Logic's Normal mode.
KEE Model 100
The Model 100 may not be the cheapest center speaker on the block, but it's an awfully good one. Styling is tasteful, with a modern high-tech flair, and the construction quality appeared very good. Like most of the other speakers in this roundup, the Model 100 is equipped with dual five-way binding posts on the back for super-easy hook up. It has two sets of them strapped together with metal strips, which can be removed for bi-wiring or bi-amplification. There are no user controls.
KEF's Uni-Q coaxial driver is perfectly suited for center-channel duty.
For starters, it produced fantastic in room measurements, with virtually flat response (±3.0 dB) from 100 Hz to 14 kHz, where the tweeter starts to roll off. Moving to the end of the couch produced nearly identical performance, 97 Hz to 12 kHz ±3.0 dB, and even at the far right the Uni-Q man aged to stay within ±4 dB from 60 Hz (there is always more bass near the wall) to 12 kHz. That is nothing short of phenomenal performance.
Sound quality was also outstanding.
Voices were natural, clean, sweet, and clear at all the listening positions. The Model 100 also delivered an excellent sense of spatiality. In other words, the sound seemed to emanate from space rather than directly from the speaker box itself, and there was a sense of depth to the soundstage even at extreme listening angles. The only minor shortfall was a tiny tonal "plump" that could husky up female vocals ever so slightly. That may have been tied to a small elevation around 250 Hz, which was apparently associated with the speaker's room position.
Dynamics were about average for this crowd. Sensitivity was 90 dB SPL at 1 meter with a 2.83-volt input (equivalent to 1 watt into 8 ohms).
The vented enclosure was tuned to 73 Hz, and the minimum impedance was 3.4 ohms at 233 Hz making this a 4-ohm speaker if I ever saw one. The Model 100 could be coaxed into over load at about the same level as my main speakers, but it should be suit able for Pro Logic's Wide mode in all but the most extreme circumstances.
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PARADIGM CC-300
ENCLOSURE: black-ash vinyl finish; ported
DRIVER COMPLEMENT: two 6½-inch woofers flanking a 1-inch fluid-cooled textile-dome tweeter
SPECIFICATIONS: frequency response, 55 Hz to 20kHz ±2 dB; sensitivity, 92dB SPL; impedance, 6 ohms nominal, 4 ohms minimum; crossover, 18 dB per octave at 2 kHz; recommended amplifier power, 15 to 175 watts
DIMENSIONS: 22 x 7¼ x 15 inches (W x H x D)
WEIGHT: 25 pounds
WARRANTY: 5 years
PRICE: $299
MANUFACTURER: Distributed by AudioStream, Dept. SR, MPO Box 2410, Niagara Falls, NY 14302
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PSB STRATUS C5
ENCLOSURE: dark oak, black oak, or gloss-black finish; ported
DRIVER COMPLEMENT: two 5¼-inch woofers flanking two vertically aligned ½-inch fluid-cooled dome tweeters
SPECIFICATIONS: frequency response, 70Hz to 21 kHz ±1.5 dB; sensitivity, 92 dB SPL; impedance, 8 ohms; crossover, 2.8 kHz; recommended amplifier power, 10 to 200 watts
DIMENSIONS: 19½x6 (W x H x D)
WEIGHT: 20 pounds
WARRANTY: 5 years (with registration)
PRICE: $500 in oak, $550 in gloss-black
MANUFACTURER: PSB, Dept. SR, 633 Granite Ct., Pickering, Ontario L1W 31
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NHT VS-2
The VS-2 has a horizontal woofer tweeter-woofer design. The back of its gloss-black cabinet sports dual five way binding-post connectors and a clever post that adjusts to tilt the cabinet so that it aims directly toward the listening area. It is a good-looking speaker, and I particularly like the way its nicely finished grille cloth stands slightly away from the cabinet's front panel.
The VS-2 delivered darn good response all along the main couch seats, ±4 dB from 83 Hz to 20 kHz directly on-axis and ±3 dB from 82 Hz to 14 kHz at 30 degrees off to the side. As with many of the speakers in this com parison, the response tilted upward slightly with increasing frequency. At 45 degrees off-axis the output developed a deep, wide hole from 600 Hz to 3 kHz.
The VS-2's sound consequently exhibited a compressed quality with a loss of detail from the wing chair, though it managed to keep the response trough from blatantly coloring vocals. Moving to less extreme angles improved matters greatly. The speaker sounded quite natural on vocals, if a little bright, from any location on the couch. This sealed system had its sys tern resonance at 90 Hz, and the impedance hit a low of 6.2 ohms at 180 Hz. Like NHT, we'd call it an 8-ohm speaker. Sensitivity hit the spec dead on at 88 dB, and the VS-2 had no trouble matching our anchor speaker bass lick for bass lick. Go with Pro Logic's Wide mode when you can.
Paradigm CC-300
Canada-based Paradigm manufactures practically all the individual parts for the CC-300, which sandwiches a 1 inch dome tweeter between a pair of 6 clear-plastic cone woofers.
The tweeter is actually squeezed slightly upward toward the top of the baffle to minimize the spacing be tween the woofers, with the goal of reducing the interference-induced response anomalies that can occur when two spaced drivers operate over the same frequency range.
The CC-300's black vinyl finish is competently applied and attractive in its own right, but the speaker is not the queen of this hop fashion-wise. Connections are made to strapped pairs of five-way binding posts; with the straps removed, the speaker can be biwired or biamplified.
My measurements seemed to con firm the validity of Paradigm's driver layout. Response hung within a narrow ±3.4-dB envelope from 82 Hz to 16 kHz, and the woofers provided tam a ±5.2-dB range from 31 Hz to 16 enough low-frequency output to main kHz at every position on the couch.
The vented enclosure was tuned to 26 Hz, indicating that Paradigm intends the speaker to be capable of working full-range. Minimum impedance was 2.8 ohms at 184 Hz, which is distinctly on the low side. Sensitivity rang in at 90 dB SPL. This baby can surely be used in Pro Logic's Wide mode in nearly any system.
At 45 degrees off-axis there was an 1 8-dB ravine centered at 940 Hz, but it was so narrow (probably because of the close driver spacing) that most listeners in the wing seats would never notice. This is a good example of ingenious response-error management.
The sound in that position was mildly hushed, reticent, and smooth - not obnoxious at all.
Meanwhile, anyone on the couch gets excellent detail, clear and articulate vocals, and an excellent "out-of the-box" presentation with only a mild suppression of ambience. At the end of the couch the CC-300 was nearly indistinguishable from the anchor speaker with most material. Moreover, the power-handling capability of the twin 6½-inch woofers meant that the anchor gave in to overload well in advance of the CC-300.
The CC-300's extended bass response also enables it to be deployed as the full-range speaker in a surround system using mini-speakers at all other locations. Don't expect full-bandwidth dinosaur stomps, but average sound tracks and good old rock-and-roll ought to come through just fine. On the other hand, the dual woofers make the CC-300 relatively large and heavy.
PSB Stratus C
PSB is another Canadian manufacturer that provides loudspeakers for just about every audio application. The Stratus CS has a pair of 5.25" woofers flanking a vertically stacked pair of ½-inch dome tweeters. For a center speaker, the Stratus C5 is unusually elegant in appearance. Its high-gloss black finish perfectly complements the tastefully sculpted cabinet. I actually like its shape a little better than the Snell's, and both of them leave the competition in the dust style wise. The C5 has no user control connections are made to a single pair of five-way binding posts.
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PSB STRATUS C5
ENCLOSURE: dark oak, black oak, or gloss-black finish; ported
DRIVER COMPLEMENT: two 5¼-inch woofers flanking two vertically aligned ½-inch fluid-cooled dome tweeters
SPECIFICATIONS: frequency response, 70Hz to 21 kHz ±1.5 dB; sensitivity, 92 dB SPL; impedance, 8 ohms; crossover, 2.8 kHz; recommended amplifier power, 10 to 200 watts
DIMENSIONS: 19½x6 (W x H x D)
WEIGHT: 20 pounds
WARRANTY: 5 years (with registration)
PRICE: $500 in oak, $550 in gloss-black
MANUFACTURER: PSB, Dept. SR, 633 Granite Ct., Pickering, Ontario L1W 31
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Like several of its competitors in this evaluation, the C5 actually had smoother midband response at the end of the couch (±2.5 dB from 92 Hz to 12 kHz) than in the center (±4 dB from 92 to 18 kHz), although it performed well from both angles. At the extreme off-axis seat, the PSB 's response exhibited a wide, deep trough, but surprisingly the main sonic effect was a compression of space and dynamics rather than major spectral errors. Ambience evaporated, and the sound of some acoustic instruments became mildly hollow, but voices escaped pretty much unscathed.
The Stratus C5 was especially clean at the end of the couch, matching the anchor speaker beautifully in most respects. Directly on-axis the sound was smooth and clean, if somewhat homogenized. Voices were clear and articulate. Spatially, the C5 was a little closed-in, especially at the far wing positions.
Dynamically, the Stratus C5 had no trouble keeping pace with the anchor speaker and its 8-inch woofer no bang, no clang, and probably okay for Pro Logic's Wide mode. Sensitivity measured 89 dB SPL, adjusted for anechoic conditions. The C5's vented cabinet was tuned to 71 Hz, and the speaker's minimum impedance was 8.1 ohms at 247 Hz, making it a true 8-ohm speaker.
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SNELL cc 1
ENCLOSURE: hand-sanded oak, dark-oak, walnut, or black-gloss wood veneer finish; sealed
DRIVER COMPLEMENT: two 5¼ inch woofers flanking a 1-inch textile-dome tweeter
SPECIFICATIONS: frequency response, 80 Hz to 20 kHz ±3 dB (anechoic); sensitivity, 89 dB SPL (anechoic); impedance, 8 ohms nominal, 5.5 ohms minimum; crossover, 2.7 khz; recommended amplifier power, 15 to 150 watts
DIMENSIONS: 16½ x 7½ x 8 inches (W x H D)
WEIGHT: 17 pounds
WARRANTY: 5 years PRICE:
MANUFACTURER: Snell, Dept. SR, 143 Essex St., Haverhill, MA 01832
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RDL RA LabsCenter Channel
A member of RDL's RA Labs line, the Center Channel uses a conventional horizontal woofer-tweeter-woofer configuration. It has pleasing but nondescript styling that will fit into most home theaters with little fanfare. The cloth grille covers the whole face of the enclosure, and dual five-way binding-post connectors are provided on the back of the cabinet.
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RDL RA LABS CENTER CHANNEL
ENCLOSURE: black vinyl; sealed
DRIVER COMPLEMENT: two 5¼-inch woofers flanking a 1-inch copolymer-dome tweeter
SPECIFICATIONS: frequency response, 55 Hz to 20 kHz ±3 dB; sensitivity, 89 dB SPL; impedance, 6 ohms nominal, 5 ohms minimum; crossover, 3 kHz; recommended amplifier power, 15 to 100 watts
DIMENSIONS: 20½ x 7 x 6½ inches (WxHxD)
WEIGHT: 10 pounds
WARRANTY: 5years PRICE: $149
MANUFACTURER: RDL Acoustics, Dept. SR, 26 Pearl St., Bellingham, MA 02019; telephone, 1-800-227-0390
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The sleek black beast pumped out 91 dB SPL when driven with 2.8 volts. Low-frequency resonance of the sealed acoustic-suspension system was at 84 Hz, and the minimum impedance was 5.1 ohms at 300 Hz. Response was within ±4.5 dB from 100 Hz to 11.5 kHz over a ±30-degree arc in front of the speaker, including directly on-axis. (Placement closer to a wall would extend the low-frequency response.) The overall shape of the response curve was fairly smooth, but a notch around 3 kHz got progressively worse as the angle off-axis was in creased.
The Center Channel sounded fairly natural, though vocals and acoustic instruments were somewhat colored. Nonetheless, it managed to keep vocals reasonably natural even from the wing seats. There was good detail, but the speaker sounded pinched spatially. The RA Labs Center Channel had no trouble keeping pace with the anchor speaker when fed large amounts of amplifier power.
By far the lowest-priced of the speakers in this comparison, the RA Labs Center Channel represents an excellent value. Like all RDL speakers, it is available only direct from the manufacturer, with a thirty-day money-back guarantee of satisfaction.
Snell CC-1
Snell gives the classic horizontal woofer-tweeter-woofer layout a clever twist. Each of the CC-1's two 5¼-inch woofers is mounted on a portion of the front panel that is angled approximately 25 degrees outward, while the tweeter faces dead ahead. This configuration worked fantastically well for all but the extreme outside listening positions.
In styling, the Snell gets my top vote in this crowd. My sample had a superb real-walnut veneer finish complemented by a graceful black cloth grille smooth and elegant. Connections are made through a single pair of five-way binding posts. There are no controls of any kind.
Straight ahead the CC-1's output was just as smooth as that of the KEF Model 100, but it was more extended, with in-room response fitting within a 3.3-dB window from 100 Hz to 20 kHz. Response was identical 30 degrees off-axis except that the treble began falling off above 12 kHz. At 45 degrees off-axis there was a 6-dB depression from 650 Hz to 3 kHz, but the tweeter was still singing at 12 kHz.
That all added up to nearly perfect spectral uniformity at any couch position. Voices were perfectly articulated and almost perfectly natural tonally. Acoustic instruments were clean and clear. The CC-i delivered a good but not outstanding sense of space, depth, and ambience in the main listening window along the couch.
Off-axis to the far side I noted that Snell had managed the response trade offs masterfully. There were no major vocal or other colorations that called attention to themselves, such as singers or announcers sounding like they had permanent colds. Instead, the anomalies leaned toward a cutback of treble and the sense of space. The sound seemed limited but clean - and, naturally, we should expect the rest of the system to help us out from time to time. The main consideration for Mr. Center is to deliver the vocals without shouting.
The sealed system had its bass resonance at 102 Hz, and impedance reached a minimum of 3.7 ohms at 239 Hz. Sensitivity clocked in at 91 dB SPL. Dynamically, the CC-i stayed right with the mains, exhibiting only mild compression at extreme volumes. Use it in Pro Logic's Wide mode when you can.
Vandersteen VCC- 1
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ENCLOSURE: black cloth wrap with wood-veneer top cap; sealed
DRIVER COMPLEMENT: 6.5" woofer with coincident-mounted 1-inch dome tweeter
SPECIFICATIONS: frequency response, 150 Hz to 21 kHz ±3 dB; sensitivity, 86 dB SPL; impedance, 8 ohms; crossover, 6 dB per octave at 3.5 khz; recommended amplifier power, 30 to 200 watts
DIMENSIONS: 12’/8 x 9¼ x l0’/s inches (W x H x D)
WEIGHT: 22 pounds
WARRANTY: 5 years (with registration)
PRICE: $495
MANUFACTURER: Vandersteen, Dept. SR. 116 W. 4th St., Hanford, CA 93230
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The Vandersteen VCC- 1 is built around a coaxial driver that marries a 6½-inch polypropylene-cone woofer with a 1-inch fabric-dome tweeter in the same superstructure. As in the KEF Model 100, the tweeter is integrated into the space normally occupied by the woofer's dust cap. This arrangement has the advantage of producing nearly the same response at every radiating angle, and Vandersteen says that it also maintains complete phase integrity.
The VCC-1 is a 22-pound box wrapped in black grille cloth and capped with a wood-veneer panel.
Mine had a neat light-oak cap, but the speaker can be ordered with a top plate to match any standard Vandersteen finish and grille color. The cabinet is almost as tall as it is wide and has thick walls with constrained-layer damping. There are T-nut inserts on the bottom for spike enthusiasts and a barrier strip with slot-head screw-terminal amplifier connections on the back panel.
The VCC-1's frequency response was very good over an exceptionally wide radiating angle: ±3.3 dB from 175 Hz to 20 kHz on-axis, with similar tolerance to 15 kHz at 45 degrees off-axis. Vandersteen also supplies a "proximity compensation" circuit - a switch that rolls off response by 5 dB below 400 Hz. The circuit is meant to compensate for the effect on the speaker's sound when it is placed next to large objects, such as a wall or a large TV screen.
Vandersteen believes that Dolby Pro Logic decoders assign too much low- frequency content to the center channel, which combines with the proximity effect to reduce intelligibility. Listening to the VCC-1 with and without compensation, I thought the circuit reduced midrange vocal content too much, making the sound too thin. The speaker actually needs a bit more low- frequency output even without the compensation. In any case, a rear mounted toggle switch turns it off -- quite good. The lower vocal registers were recessed and very mildly colored with a faint trace of hollowness. Spaciousness was relatively limited, with most of the sound seeming to come directly from the speaker. But the performance of this speaker remained virtually unchanged even at the far left and far right listening positions, so there will be no loss of sound quality in the tough seats.
Dynamically, the VCC-1 matched the anchor speaker stride for stride. Sensitivity registered 87 dB SPL. It should be okay for Wide mode most of the time. The sealed system's crossover design delivers a very flat impedance curve up to 320 Hz (475 Hz with proximity compensation), where it measured 4.9 ohms, drifting upward to a maximum of 8.1 ohms at 990 Hz and then falling to a minimum of 4 ohms at 20 kHz.
Yamaha NS-AC300
The Yamaha NS-AC300 has a classy gloss-black cabinet with a sloped front panel that enables it to be aimed about 15 degrees downward when the speaker is placed on top of a TV or upward if it is placed below the TV on a shelf or even on the floor. The speaker also comes packaged with a 10-foot section of polarity-coded speaker cable.
A back-panel level control permits tweeter attenuation above 6 kHz to suit listener tastes.
The NS-AC300 has two 6½-inch woofers in the standard horizontal lay out, one on each side of its 1-inch dome tweeter. Its on-axis response was within ±5.5 dB from 92 Hz to 20 kHz, with a wide notch from 3 to 8 kHz. At the couch-end seats, 30 degrees off axis, the center of the notch moved downward to about 3 kHz, and at 45 degrees it split into a pair of deeper but narrower notches, one centered at 725 Hz, the other at 2.2 kHz. Sonically that gave the main listening seats accept able vocals and dialogue, but with a hollow, distant character and little depth, width, or detail. As we moved to the end of the couch and beyond, vocal colorations remained in check, but the sound became progressively huskier and more compressed spatially.
With two relatively large woofers, the NS-AC300 had no trouble matching the anchor speaker note for note on electric bass. Sensitivity clocked in at a healthy 92 dB SPL. The sealed system had a resonance frequency of 96 Hz, and the minimum impedance was 5.4 ohms at 9 kHz.
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YAMAHA NS-AC300
ENCLOSURE: gloss-black; sealed
DRIVER COMPLEMENT: two 6½-inch polypropylene woofers flanking a 1-inch titanium-dome tweeter
SPECIFICATIONS: bandwidth, 50Hz to 20 kHz; sensitivity, 90 dB SPL; impedance, 8 ohms; crossover, 6 kHz; recommended amplifier power, 10 to 200 watts
DIMENSIONS: 23½x7½x9½ inches (W x H x D)
WEIGHT: 21 pounds
WARRANTY: 3 years PRICE: $299
MANUFACTURER: Yamaha, Dept. SR, P.O. Box 6660, Buena Park, CA 90622
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Closing Thoughts
Any of the speakers reviewed here can be successfully employed for the center channel in a good home theater system. The KEF and Snell models, especially, are suitable even for very high-performance systems, particularly when matched with appropriate speakers from their own lines for front left and right duty. And those two models, along with the Paradigm, PSB, and NHT entries, will compare favorably with topnotch conventional speakers at listening positions within 30 degrees off center on either side.
For users who have extreme wing seats (like me), the KEF, Snell, and Vandersteen will deliver the goods to either side with little or no compromise. Avoid using the ADS in Dolby Pro Logic's Wide mode, which will overstress its low-frequency capabilities. The Paradigm, on the other hand, could be used as a super-full-range center with enough bass to support a system with mini-speakers at the front left and right positions.
Source: Stereo Review (09-1995) By Tom Nousaine