Snell Acoustics Type A Reference loudspeaker
The circa-1984 Type A/III Improved was a hefty system, with a total shipping weight just over 300 lbs. The Type A Reference doubles the weight and quadruples the former loudspeaker's suggested retail price. However, all Type As have remained faithful to Peter Snell's highest priority, which was the production of a uniformly flat amplitude response by addressing the interaction between the speaker and the nearby room boundaries. In so doing, the new Type A Reference makes the powerful reproduction of deep bass a top priority.
The former Type A/III-Improved was more of a modification than a redesign, involving the addition of a new Danish VIFA tweeter, a rebuilt internal baffle, and a retuned crossover. It was reviewed in these pages in March 1990 (Vol.13 No.3, footnote 3), JA's measurements revealed an "ultraflat frequency response" and a "superb coupling of low frequencies with room acoustics." Although bi-amplification extended the speaker's dynamic range, the Type A/III failed to achieve Stereophile's top recommendation because of a lack of treble transparency and a shallow image depth. The new Type A was auditioned here to determine if its new away-from-the-wall modularity results in better image depth and improved treble transparency.
Although I was familiar with the previous Type A's four shipping cartons, I wasn't prepared for the stream of boxes that arrived from the Snell factory at Haverhill, Massachusetts (two subwoofers and a crossover), from Stereophile headquarters in Santa Fe (two Reference Towers, two outboard passive networks, and a set of unlabeled cable looms), and Utah (a separate set of labeled cable looms from Kimber Kable). In total, I opened a dozen shipping cartons before assembling this system. Two of the truck deliveries exceeded 300 lbs!
Snell ships the main speaker enclosures in huge reinforced cardboard boxes. The subwoofers are packaged in stout 19.5" by 23.5" by 50.75" 150-lb cartons, and the towers in tall 16.5" by 19.75" by 68.5" 150-lb cartons. The subwoofer containers were the most difficult to get a purchase on, requiring the combined strength of two people to move them up the six steps from my front hall to listening room (footnote 4). Owners shopping in this price range deserve and should insist on dealer installation.
Despite this massiveness, the subwoofers are controlled by a surprisingly small electronic crossover box, the EC-200. This tiny device is powered by a power "brick," which plugs into a power receptacle at the right edge of the back panel. The 18dB/octave high-pass filters use a Butterworth filter configuration, while the low-pass's 24dB/octave slopes are modeled on Linkwitz-Reilly curves. One input and two outputs for each channel, plus a single summed output for one subwoofer, are available on gold-plated, single-ended RCA outputs. The EC-200's chassis is just too light, considering the size, weight, and torque applied by some heavy audiophile cables. Peter Lyngdorf, president of AudioNord and the sole shareholder in Snell Acoustics, advised me that the company plans to replace this tiny EC-200 with a rack-mountsized electronic crossover that offers both single-ended and balanced connections. All current owners will be offered this update at no cost.
Kevin Voecks, who recently left Snell to start his own company, designed the system's SUB 1800 subwoofer to deliver bass down to 20Hz in large listening environments, but to be a separate enclosure so it can be moved to the best spotsay, in a corner or against a wallwithout worrying about the midrange imaging.
The subwoofer meets THX specifications of 105dB output at 1m for most environments, including the top specification for a 9000 cubic-foot room. Tom Norton (footnote 5) called this a "brute-force design." It uses a single 18" driver in a fourth-order bass-reflex cabinet with a front-mounted port. TJN described the subwoofer's port extending to the back of the cabinet, then turning 90° to run farther internally. The cone driver has a resonance of 28Hz and the port has a resonance of 14Hz. This 18" driver has a 3" excursion, and is equipped with two spiders to prevent twisting when driven with large signals. The subwoofer cabinet can be positioned on its narrow or long sides. With the subs mounted on their sides, as TJN had them in his Snell Music & Cinema review, the 18" driver and the port are equally close to the floor. Tom indicated that this may deliver the most bass reinforcement. One can also mount them vertically, with either the port or the driver closer to the floor.
The Type A Reference Towers, on the other hand, were designed to be placed away from walls and out into the room, thus optimizing imaging and depth of field in a way that the back-wallsituated older Type A could not. Freed of a large woofer driver and the passive crossover network, Voecks was able to make the towers very narrowthe Reference towers are only 9" wide; the previous Type A was 23.5" wide. In fact, he designed the towers to be as wide as the human head. He explained that his experiments suggested that narrow loudspeakers are better at producing an illusion of depth.
The Towers feature a computer-modeled, tiered baffle supporting seven drivers arranged vertically in a so-called D'Appolito configuration. This array is vertically symmetrical, with one handmade 1" textile tweeter at center, flanked by a set of three drivers each above and below. Each flanking set consists of one 5" cast-magnesium basket, mineral-filled midrange drivers, and two 6.5" cast-magnesium basket woofers with mineral-filled polypropylene cones. This driver array uses the company's Coincident Virtual Image (CVI) technology, which is designed to create a virtual image of the midbass and midrange that coincides with the tweeter's for improved imaging.
Voecks said that the Reference Tower arrays generate a number of room or floor reflections at staggered time intervals. This minimizes the overall impact of these reflections on the loudspeaker's response because each driver is a different distance from a room boundary. As on earlier Type A loudspeakers, there's a rear-firing metal-dome tweeter, which is said to flatten the Type A's power response in the room by adding HF energy to compensate for the loss due to the front tweeters' increased directivity at higher frequencies.
The Reference Towers' narrowness led Voecks to move their passive crossover networks into separate, shorter, but similarly styled enclosures. As TN pointed out in his review of the M&C Reference System, the crossover network circuit boards had to be so large as to allow enough space between individual components, such as open-air coils, and to remove the crossover boards from the vicinity of the eight powerful loudspeaker magnets. Each passive network enclosure features an elaborate hookup panel with a top section for fuse; a switch and level control for the tower's rear tweeter; a center section of four jumpers to set the front tweeter levels at +1dB, calibrated flat, 1dB, and 2dB; and a middle section of input jacks to take the audio signal from the upper-range stereo amplifier. Jumpers in this section allow the owner to separate the high- and low-frequency tower drivers for bi-amping or bi-wiring. Finally, the bottom section contains four pairs of four-way binding posts for connections to the Reference tower.
Footnote 1: The Audio Critic, Vol.1 No.4, 1977, pp.3839.
Footnote 2: Snell Acoustics markets a Home Theater version of the Type A Reference: the Snell Music & Cinema Home THX Reference System. This system costs $11,000 more than the Type A ($29,993 vs $18,999), has more components than the Type A (10 for the Music & Cinema System vs seven for the Type A), and has the THX-standard multiple tweeter array in each Reference Tower (three forward-firing 1" textile dome tweeters in the Music & Cinema vs only one in the Type A). Tom Norton reviewed this system in Stereophile Guide to Home Theater, July '95, pp.103111, and gave it high marks.
Footnote 3: That was the Type A's tenth review in American audio magazines, and one of the more favorable.
Footnote 4: We used our legs, not our backs, to ramp the carton up the steps. This involved putting the top of the thigh under the part of the carton facing downstairs and extending the leg. As the leg extends, it gradually pushes the box's weight up as it slides up the stairs. It is possible to "push up" hundreds of pounds with quadriceps strength, even if one's back wouldn't tolerate lifting a fraction of that weight above waist level.
Footnote 5: The Type A Reference Towers differ from those in the company's M&C Reference System in having two more tweeters (to meet the THX multiple-tweeter specification) in the Tower's front array, for a total of nine drivers.