Spica TC-50 loudspeaker Anthony H. Cordesman Follow-up
I was more than a little surprised to read JGH's recent review of the Spica TC-50 with Spica's powered Servo-Subwoofer. Gordon found the TC-50s to be bright and hard, which seemed to overshadow his impressions of the new combination of TC-50s and Servo-Subwoofer. In contrast, I have previously found the TC-50's highs to have a gentle rolloff, and the TC-50 to have one of the most listenable upper midranges of all small monitor speakers.
After discussing the subject with a distinguished panel in Santa Fe, I came to the conclusion that Gordon's displeasure with the TC-50s might have been caused by a defective sample (footnote 1). Now that I've had the chance to fully audition a new pair of TC-50s, along with their Servo-Subwoofers, I increasingly think this likely. My impressions differ enough from Gordon's to justify a follow-up review.
In terms of overall sound quality, my impression is that the combination of the Spica TC-50 and Servo-Subwoofer is a good to very good full-range speaker system. If anything, the highs and upper midrange in the TC-50s seem just a bit softer in this combination, due to the masking effect the extra power of the Servo-Subwoofer adds to the bass. Where the slight apparent rolloff in the highs of the TC-50s, when used by themselves, helps compensate for their lack of bass, they lose a little of their balance and musically realistic timbre when used with the Servo-Subwoofers.
The Servo-Subwoofers do, however, offer some important advantages: they improve the dynamics and soundstage of the system. The power-handling capability of the regular TC-50 has always been a bit limited, and the use of a matching pair of Servo-Subwoofers opens up the soundstage and adds depth to it, balancing out the TC-50's superb imaging.
There is no question that the added bass information from the Servo-Subwoofers adds a vital amount of life to the TC-50. The TC-50s are better than most small monitors in this regard, but come close to losing the impact and emotional content of any music with powerful bass content. The Servo-Subwoofers do a good job of restoring bass dynamics, and its emotional impact, to the music.
At the same time, I am not entirely happy with the way in which the Servo-Subwoofer blends with the TC-50. The theory behind the Servo-Subwoofer is excellent: Spica has concluded that, with the right crossover and speaker, a polarity-inverted Servo-Subwoofer will actually be more in phase than a noninverted unit, and will produce far less smearing in bass imaging and instrumental placement within the soundstage. Spica feels that conventional crossover approaches create phase error and time delay, and account for the tendency, so common in many otherwise good subwoofer systems, to fragment the image in the bass and midrange (though the actual crossover is quite low, subwoofers are still contributing significantly to the overall output well into the lower midrange).
Footnote 1: I also considered this possibility, since I had heard the TC-50s sound significantly better in JGH's basement a year before (prior to their woofers giving up). John Bau, however, didn't think JGH's pair had anything wrong with them, and declined to submit a second review pair, even after hearing the TC-50/subwoofer combination at JGH's house (though he definitely felt the review conditions there to be subpar).—Larry Archibald