Spica TC-50 loudspeaker Page 2
The speakers must also be toed-in to fire straight at the listening position, the result otherwise being a prematurely rolled-off treble and a lack of vitality to the sound. Image precision also suffers. Ah, image precision...
There is a fundamental test of a pair of speakers' ability to produce a well-defined image that owes nothing to any real musical event, whether acoustic, electrical, classical, rock, or jazz. For a while forget about "soundstaging," image depth, and other such subjective buzzwords. All you need do is play monophonic pink noise through both speakers simultaneously—many test CDs have a suitable track, the only important point being that the output from both speakers be identical—and listen carefully to where the phantom image of that mono noise seems to come from. All you need to know is that a perfect pair of loudspeakers would produce an infinitely thin point of noise, with every frequency component of that noise positioned at the same place in space.
Real, rather than perfect, speakers will depart from that paradigm in two ways: first, that phantom image will acquire size; second, at some frequencies the sound will appear to come from somewhere else altogether, the image often "splashing" to the sides, or even behind you if one of the speakers has a drive-unit inadvertently wired with the wrong polarity. Careful adjustment of speaker and listening position, making sure that there are no acoustic obstacles to the sides of the speakers, should minimize any such image splashing.
If your speakers can produce a narrow mono image at all frequencies, then they will allow your ears to accurately decode the information present in two-channel recordings and synthesize a stereo image, a soundstage between and behind the loudspeakers—maybe even above them! Contrariwise, if your speakers are unable to produce this narrow mono phantom image at all, then no matter how spacious the sound on music recordings, that spaciousness will be an added function of the hardware, not anything intrinsic in the recording—it will be inaccurate, and even pleasant inaccuracy is not what this magazine is about!
This is about the most fundamental test of the imaging ability typical of a pair of loudspeakers—there's nowhere to hide. If a pair of speakers can perform well on this test, then every soundsource in a recording will appear to come from its correct position in space; there will be no spatial distortion. And that applies to all the ambience and reverberation captured on the recording. If these are also correctly positioned in space, then the ear/brain will create the appropriate image depth—if you hear what appears to be the direct sound from a soundsource and a coherently reproduced reverberant soundfield associated with that direct sound, then you can't help but hear that soundsource as being further away.
The best speakers in this respect I have heard in my current listening room are the Rogers LS3/5a, Celestion SL700, and Martin-Logan Sequel II, all of which are more expensive, two considerably so, than the Spicas. I have also heard the $4000/pair Quad ESL-63s give a similarly tightly defined central image from a mono source. Yet the budget-priced TC-50s join that select group, from the midrange on up producing a tightly defined, narrow central image. Only in the lower midrange did the mono image spread appreciably, and nothing I could do with the speakers' position would change it. I can only assume it is due to colorations in this region specific to each individual loudspeaker.
But it didn't prevent the pair of TC-50s throwing a well-defined soundstage with impressive depth. The crowd noises at the beginning of Pat Metheny's As Falls Wichita, So Falls Wichita Falls (ECM 1190), for example, appeared to be coming from behind the rear wall of my listening room. And on the cassette copy of Poem, the new Stereophile flute and piano recording, the images of the musicians had—here comes that phrase again—a palpable presence. In the words of the Anarchist, there was a lot of "there" there.
And that "there" was spatially accurate. On my recording of Anna-Maria Stanczyk playing Chopin on the original HFN/RR Test CD, many speakers seem to reproduce this single-point-mic-captured track as either rather diffuse, or in fat mono. On the Spicas, as on LS3/5a's, you can hear quite unambiguously that the Steinway soundboard extends from just left of center to about halfway toward the right speaker, just as I had intended it to when I made the recording. And around the piano image, you can hear the acoustic of the hall gently stroked into vibration to produce a dome of surrounding reverberant ambience.
This delicacy at achieving spatial resolution was not achieved at the expense of a live feel to the sound, there being a suitable immediacy overall. Whether this is due to the time coherency of the sound, or HF detail in the relatively neutral lower treble slightly pointed by the added energy in the room in the top octave—mellow these Spicas aren't—is open to debate. Nevertheless, while not approaching the transparency of, say, the Sequel II or Vandersteen 2Ci, to name very disparate designs that both perform well in this area, there were lacks both of confusion and of "grain," as it were, in the upper midrange and lower treble that helped the music to communicate very effectively. "Psychokiller," from the live Talking Heads album Stop Making Sense (Sire 9 25186-2), if lacking in ultimate loudness, was almost as intensely dynamic as I can remember. (Mission 780 Argonauts hold the prize here.) The only real restriction on dynamics seems to be due to the TC-50s' lower treble hardening as the sound pressure level reached the high 90s.
Lower down in frequency, I was surprised to discover that the mids were rather more colored than I expected, a slightly woody texture overlaying the tonalities of instruments in this region and thrusting instrumental images with a lot of energy in this region forward toward the listener. The lower registers of my piano recording, for example, sounded nearer the mic than the upper, when, of course, the opposite was actually the case. (This anomaly is also due to the fact that, in absolute terms, the presence region was a little laid-back.) Coupled with the rather lispy HF, this coloration is perhaps the only indication that you are listening to a $550/pair of loudspeakers rather than a $1500/pair.
Finally, as might be expected from such a small enclosure, the low bass was restricted in weight. However, definition was good in this region, and a slightly overdamped character noticeable when the speakers were first plugged in, which made the sound too thin, too small, was significantly ameliorated over the first two weeks of listening.
It is a couple of years since I last heard a pair of the original Spica TC-50s under critical circumstances, so any comparisons between old and revised versions would be invidious. However, the Spica TC-50 remains a musical bargain when treated on its own terms. Good stands must be used, room placement is critical, and the listener must take great care that he or she sits on the speaker's optimum axis if the sound is not to become thin and peaky in the treble. But then, even given the speaker's lack of low-bass weight, the result will be true high-end sound, excellent soundstaging and presentation of detail being coupled with a musical tonal balance and a taut upper bass. Highly recommended.—John Atkinson
Footnote 2: In Vol.9 No.5, p.111.—John Atkinson