Celestion 3000 loudspeaker Page 2
The woofer is a relatively conventional 8" unit (the diameter of the radiating area is around 65/8") with a flared polyolefin cone (footnote 3) and a synthetic molded rubber surround, built on a cast-alloy frame. The crossover is constructed on a printed circuit board and features third-order slopes, with the woofer fed by a low-pass network consisting of two series ferrite-cored coils and a shunt resistor/electrolytic-capacitor combination. Surprisingly, the connections to the woofer are by push-on lugs rather than soldered joints. The tweeter is fed by a physically separate third-order high-pass filter, this comprising an air-cored coil and, again, non-polarized electrolytic capacitors.
The ribbon's stepdown transformer is quite small and appears to be constructed on a conventional EI core. Thick, 10AWG, 84-strand cables connect the transformer to the ribbon. Electrical connection is via two pairs of gold-plated Michell terminal posts lined up horizontally; somewhat peculiarly, the inner two terminals are for the woofer, the outer two for the ribbon. Some specialist cables may therefore not have sufficient free-end length to allow connection. For those not wishing to bi-wire or bi-amp the 3000s, wire jumpers are supplied to connect the two hot and two ground connections together.
The enclosure is constructed from ¾" MDF, with an inset rear panel to increase rigidity. Both woofer and ribbon sub-enclosures are additionally braced with a side-to-side vertical panel, called by Celestion a "figure of 8" brace, though the one for the woofer enclosure actually has three openings—a "figure of 12" brace? A little disappointingly at this price level, the cabinet is finished in black woodgrain vinyl. (The $2199/pair model 5000 is identical, but finished in real wood veneer, while the considerably more expensive floorstanding 7000 marries the ribbon to two 8" woofers.)
Though the $399/pair "K" stands are said to be optional, they should really be considered essential. Matching both the 3000's gray-and-black colors and truncated-rectangle vertical profile, these stands feature two triangular-section pillars which can be filled with lead, dry sand, or a mixture of both. The flat top plate has a small central hole, as does the base of the speaker, allowing a short length of dowel to give firm location, while Celestion recommends Blu-tack or a similar compound to bond the two together. Carpet-piercing spikes are provided, with the useful bonus that one for each stand has a horizontal wheel attached. Leveling the stand to compensate for an uneven floor beneath the carpet is thus simple and quick.
Overall, disregarding my grumbles over the vinyl finish, the 3000's construction and that of the matching stands are to a superb standard.
Unusually for a high-end loudspeaker, the 3000s are intended to be used in close proximity to the rear wall—the excellent handbook recommends a spacing of 6". This leads to a little difficulty in my listening room as almost the entire wall behind the loudspeakers is faced with LPs and books and therefore doesn't offer a constant speaker-to-wall distance. (In all fairness, you may ask, why I am then reviewing this loudspeaker? The answer has to be that it was Hobson's choice, the other members of Stereophile's reviewing team having rooms that were even less suitable.) I ended up with the speakers situated some 4" in front of the records.
I have to say that I have never found such a close wall placement to give optimal results with any speaker, in this room or in any other. Certainly, the additional loading presented to the speaker by the wall at low frequencies extends bass extension and adds to the feeling of subjective weight to the sound. However, this is also one of the best—or should that be worst?—positions to excite room standing waves, the result being a lumpy, sometimes ill-defined LF register (footnote 4). The only exceptions I have heard are speakers like the Linn Kan, where the speaker's bass response is so restricted in the first place that the added excitement of room problems is to a significant extent avoided.
The next siting problem concerning the 3000 is how far away from the sidewalls to place the pair. Not only does the exact position affect the degree and nature of the excitation of room resonances, it will also determine how far off the ribbon axis the listener ends up. Celestion recommends the speakers be sited somewhere between 24" and 48" from the sidewalls. In my room, which is set up so that it is wider than it is long, the placement giving the best balance between treble and bass was a little further away than this at 60", which meant that the listening seat was approximately 30° off the ribbon axis. Moving the speakers closer to the sidewalls both over-accentuated the upper bass and brought my listening chair too much on to the ribbon axes, where the sound became too bright.
Not that this speaker could ever be accused of being dull! (Unless you listen to it standing up.)
Throughout my auditioning of the first samples of the 3000 I was reminded that the mid-treble was being accentuated. Paradoxically, the speaker also lacked top-octave air. At lowish listening levels, this character made the sound quite enjoyable: the bright character added a sense of life and detail, while the overall depressed response above 10kHz made the speaker sound sweet on recorded violins. The depressed HF, however, meant that cymbals and other treble-rich percussion instruments failed to excite the recorded acoustic to the same extent noticeable with other good loudspeakers. But as the replay level increased, my tolerance for the treble balance diminished proportionately. Such already overcooked recordings as Andreas Vollenweider's Dancing with the Lion (Columbia CK 45154) became unlistenably bright at anything other than background levels. And forget about my usual test for speaker brightness—whether I can stay in the room with Thomas Dolby's Aliens Ate My Buick album (EMI/Manhattan CDP-7-48075-2) played at high levels. Via this first pair of 3000s, I didn't want to stay in the room even at low levels.
Footnote 3: "Olefin" is a 25-cent word for a hydrocarbon of the methane/ethane type (though I wasn't aware that such compounds could be persuaded to form polymers.) Don't be afraid to use this word in mixed company or if children are present.
Footnote 4: This can easily be shown by Ralph Gonzalez's program for IBM PCs and compatibles, The Listening Room, an early version of which I described in the April issue (p.89). The user enters his or her room dimensions, then uses the computer cursor keys to position a pair of speakers in the room (all three dimensions for each speaker are independently adjustable); a graphic representation of the degree to which the room modes are excited then appears on the screen.