Snell Music & Cinema Home THX reference system
Nine separate pieces comprise the Snell M&C Reference system (the photo shows only seven, leaving out the outboard crossover networks for the main left and right Towers). In a custom installation, you could, if you had a resourceful installer, conceal all but two of the enclosures (the left and right main channelswhich, like all good freestanding loudspeakers, should be placed away from nearby walls).
But in many installations, the entire system will be visible, even in very large rooms. Fortunately, most of the piecesother than the subwoofersare elegantly styled. Despite all of the cute little subwoofers flooding the marketplace, uncompromised reproduction of the bottom octave still means large boxes, and my samples of the SUB 1800s looked very much like small black refrigerators. They might be less conspicuous in something like the available light oak, but nothing outside of a baronial Home Theater room will make them look small. Finding a creative way to conceal themafter you've determined the best location for themis the best solution.
The main loudspeakers of the Snell M&C Reference System are the sleek Music & Cinema Reference Towers, just over 5' high. If you could remove the grilles (footote 1) you would see the nine drive-units arranged vertically in a so-called D'Apollito array, with the by-now-familiar THX multiple-tweeter setup (three in this case) in the center. (A true D'Apollito configurationwhich is designed to smooth a system's vertical dispersionuses third-order networks, as do the Snell Towers, except for the fourth-order low-pass circuit on the woofers).
The tweeters in the Snell system, as with many such multiple-tweeter arrays, use neodymium magnetsthe main benefit of which is their small size, which allows the tweeters to be placed very close together. Flanking the tweeters above and below are, first, the two 5" midrange drivers, then the four 6.5" woofers. In case you've been on the moon, the purpose of the multiple tweeters is to meet the THX's mandated limited vertical dispersion, which is intended to minimize floor and ceiling reflections.
To a lesser extent, the symmetrical midranges and woofers should also contribute to this narrow vertical dispersion in their respective ranges. The three tweeters don't all cover the same frequency band; the top and bottom tweeters only go up to about 9.5kHz, the center tweeter alone operates above that point. This is said to minimize interference effects and smooth the vertical dispersion in the top octave. The narrow front aspect of the baffle, along with the use of felt pads around the midranges and tweeters, minimizes diffraction problems.
The individual baffles of each of the Towers' drivers are also stepped back slightly, with the tweeters recessed the most, the woofers the least. Presumably this is to assist in time-alignment of the system, though Snell, characteristically conservative about such things, makes no such claim in their literature. The crossover network for each tower is externally located in a shorter, similarly styled enclosure. The eight terminals on the back of this crossover are linked to eight terminals on the back of the tower via a furnished, color-coded cable loom (made by Kimber). Some care should be exercised in connecting the two pieces together to ensure that the hookup is correct. The Towers have no internal protection (series capacitors or other such) for the individual drivers. While damage is unlikely to occur to the woofers or midranges by an incorrect hookupunless you jump immediately to "Jurassic Lunch" on Telarc's The Great Fantasy Adventure Album (CD-80342)feeding bass to the tweeters at high volume may well be fatal to them. It's not difficult to hook up the crossover correctly, but neither is it foolproof.
The purpose of isolating the crossovers for the Towers in a separate enclosure has, according to Snell, nothing whatever to do with vibration, which they consider to be a non-issue with the passive components used in a crossover network. Rather, it's to both remove the crossover elements from the vicinity of the drive units (and their associated magnetic fields) and to allow for a less-crowded layout of the network itself to minimize the interaction of its various elements. The Towers are the only elements of the M&C Reference System that are designed with external crossovers. The Towers are also set up for optional biwiring (as is the LCR 2800 center channel).
The almost square LCR 2800, used here as a center channel, is the only piece in the M&C Reference system that's magnetically shielded. It has a considerably different driver arrangement from the left and right Towers, as you might expect from the radically different cabinet design. The tweeters remain centered with the midrange drivers above and below. The woofers, however, are positioned to the left and right of this mid-tweeter array, which permits a cabinet shaped to fit below or above a screen (or behind it, if you use a two-piece projection system with a perforated screen).
Both the midranges and the woofers are different from those used in the left and right Towers. The mids here are smaller 4" unitsSnell's specs incorrectly list them as 5" unitsthe woofers larger at 8". The sonic match between the center and main loudspeakers is very close. While with pink noise the center channel seemed to be slightly "chestier" than the lefts and rights did, that discrepancy was likely due to the different positioning required for it (closer to the floor and the wall behind). On actual program materialboth music and videoI was never conscious of any spectral imbalance across the front of the soundstage.
The baffle of the LCR 2800 is also staggered, and felt is also used in appropriate areas to minimize diffractiona more significant problem with the center loudspeaker's wide-frontal-aspect cabinet. The grillein this case removableis also designed for minimum sonic interference. I used the system with the center grille in place. Since the left and right Towers need their grilles, it makes sense to also use the center's grille. Besides, the 2800 LCR is just plain ugly with its drive-units exposed.
The SUR 2800 Tower surrounds, while slender, are more than 7' tall. They are, of course, dipolesanother THX requirement. Here, however, the dipole arrayfront- and back-mounted woofer/midranges and tweetersis augmented by a single 8" woofer mounted on the forward-facing baffle. This extends the speaker's response down to a specified 36Hz. Whether or not such expanded response is needed in the surrounds is still controversial. For Pro Logic, there's not supposed to be any response much below 80Hz. There does appear to be deeper surround-channel bass on much Pro Logic material; Dolby argues that this is merely leakage and simply duplicates the bass content found in the front channels.
The new discrete 5.1-channel formats will have full-range response in all of the channels. How often this will be used by filmmakers (in light of the restricted low-frequency capabilities of theater surrounds) is still an open question. And the bass-management schemes, which will be provided in the new AC-3 processors, will allow the user in any case to route the rear surround bass to the main channels or subwoofer(s). In any event, Snell has covered the bases here in their price-no-object system; the surrounds may not have subterranean bass, but they are full-range.
Two ergonomic criticisms of the big Snell surrounds: The bottom of the cabinet, or nearly half of its entire volume, is not part of the woofer cabinet. Its only function is to raise the system to the proper height. Because the drivers are at the top of the cabinet, the speaker is decidedly top-heavy. While it may be "walked" around the room during positioning, care must be taken to keep it from toppling over. It's not particularly unstable when in its final position, though it should be spiked on a carpeted surfacespikes are provided for the surrounds and the left and right front Towers. (Without the spikes on my carpet, it resembled the Leaning Tower of Pisa, since its 8" woofer makes the front of the cabinet heavier than the back.)
It would have made more sense to build the surrounds in two pieces, which the user would then bolt together. This would allow the bottom pieceessentially a stand for the top halfto be filled with sand, effectively eliminating the top-heaviness of the system. It would also make for simpler packing and shipping; the boxed surrounds are long. They wouldn't fit upright in my garage while awaiting unpacking.
Finally we come to the SUB 1800 subwoofer, which is a huge, brute-force design. The cabinet's volume is approximately 7ft3, its 18" driver ready to rattle your sacroiliac. The large, front-located port extends to the back of the cabinet, then turns 90° and travels a farther distance internally. The subwoofer's 120 lbs (shipping) make the cabinet feel much heavier when you're moving it. It's unpowered, with a single set of input terminals on the rear panel.
I set up the Snell Music & Cinema Reference System in my approximately 22' long by 18.5' wide by 12' high audio/video room. The 18.5' dimension opens to a large entry and dining area in the last two-thirds of its run on one side, significantly increasing the cubic volume of the space. (A diagram of this room is found in my "Matter of Taste" sidebar in May '94; Vol.17 No.5, pp.9899). With the subwoofers positioned on their sides (more on this later), the front arraysubs, Towers, crossovers, and center channeltook up nearly 18' of this dimension, with less than a foot of breathing space between each enclosure. In light of this (and echoing my comments earlier about the subwoofers), I believe one of the lighter wood finishes would allow this system to blend in better with its surroundings than the basic black of my samples. Clearly, using the Snell flagship M&C system requires a certain degree of commitment and/or a large room.