Spica TC-50 loudspeaker John Atkinson
"Why does John Atkinson devote so much of his time to loudspeakers selling for under a [sic] $1000?" wrote a correspondent to The Audiophile Network bulletin board in August, there being a clear implication in this question that "more expensive" always equates with "better" when it comes to loudspeakers. While it is true that the best-sounding, most neutral loudspeakers possessing the most extended low-frequency responses are always expensive, in my experience this most definitely does not mean that there is an automatic correlation between price and performance. I have heard many, many expensive loudspeakers whose higher prices merely buy grosser sets of tonal aberrations.
For those on modest budgets, provided they have good turntables or CD players, a good pair of under-$1000 loudspeakers, coupled with good amplification, will always give a more musical sound than twice-the-price speakers driven by indifferent amplification and a compromised front end.
End of discussion.
Having spent time in recent issues with relatively expensive speakers, ranging from the $1195/pair Vandersteen 2Ci to the $4000/pair Pioneer TZ-9, with stops along the way at the $1999/pair Celestion SL600Si and the $2500/pair Martin-Logan Sequel II, I thought it appropriate that I should return to my Cheapskate roots by looking at two small, insensitive, sealed boxes featuring limited low-frequency extension that, while epitomizing the adjective "cheap," do have high-end pedigrees.
Extremely familiar to Stereophile readers since they were first written about in the magazine by Anthony H. Cordesman back in 1984 (Vol.7 No.2), the $550/pair Spica TC-50s last appeared in these pages when Martin Colloms reviewed a pair in Vol.11 No.1. Since then, this diminutive loudspeaker has been slightly revised, as well as suffering a price increase, so I thought it would be useful to give a listen to the latest version.
Quickly to recap the basics, the TC-50 uses an unusual triangular enclosure, with just the side panels finished in veneer. Electrical connection is via closely spaced, knurled mounting posts carried on a small panel on the speaker's rear. Clearance around the posts is minimal, meaning that heavy-duty, stiff speaker cables are easiest connected with banana plugs, which some might feel to be a slight source of degradation when compared with a good lug connection.
The tweeter is a version of the venerable French Audax 1" fabric-dome unit, while the woofer is a 6.5" paper-cone unit, heavily doped by Spica and again sourced from the Audax company. Both drivers are mounted on the sloping face and surrounded by a ¾"-thick felt blanket. The crossover was optimized by computer and consists of a unique combination of a quasi-first-order high-pass slope, and a fourth-order Bessel-response low-pass slope, with both drivers connected with the same polarity. Together with the time-alignment conferred by the sloping baffle, this is said by the speaker's designer, John Bau, to confer a linear amplitude and phase response on the loudspeaker (footnote 1).
Changes compared with earlier TC-50s are the addition of a bracing rod between the baffleboard and the cabinet rear, a revised crossover, a redesigned felt blanket, and improved drive-units. The result is said to be increased sensitivity and power handling, improved imaging, and a more extended top end, now reaching 16.5kHz rather than the original's 14kHz.
Owners of older TC-50s can have their speakers updated by the factory for $250/pair—phone Spica before shipping the speakers in their original packing to get an RA number. The speakers are completely disassembled, rebuilt with new drive-units, and tested. Spica will extend the original warranty for five years from the date of revision.
The Spica manual is both well-written and accurate regarding how to get the best sound from a pair of TC-50s. It goes into some detail on where to place the speakers in the room, particularly emphasizing the need to allow the speakers to run-in for at least eight hours and the necessity to listen to the speakers on the correct vertical axis. Regarding the warm-up, I left the TC-50s repeating Kraftwerk's Electric Cafe album while I spent one more day (one of many) at the office trying to integrate all the comments from Stereophile's team of dedicated reviewers—hi guys, hope you got home from Santa Fe okay—into this month's "Recommended Components" listing. Even then it was apparent throughout the first week's listening that the midbass was still becoming looser and the overall balance warmer with every record I put on.
Regarding the listening axis, I found it to be at least as sensitive as Spica says, differences in listening height of 1" noticeably affecting the upper treble balance. To get the optimum frequency and phase response intended by John Bau, it is essential that your ears be on a level with a point halfway up the enclosure; ie, with your ears level with the top of the woofer cone. If the combination of your listening chair and stands results in a listening axis any different from this, the speakers must be tilted up or down accordingly. Listening even slightly below this axis results in a depressed HF balance, very noticeable on recorded spoken voice; if you listen any higher, the speaker's top octaves become both increasingly disparate from the rest of the treble and exaggerated in level.
Footnote 1: See "Interstellar Overdrive," Vol.11 No.2, February 1988.—John Atkinson