There has been a long history in high-end audio of super-tweeters and, more commonly, subwoofers to enhance the overall performance of a listener's speaker system. As I mentioned in my past review on the REL Acoustics T-7 subwoofer, the major advantage of using a subwoofer, if properly set up, is not just to lower the frequency extension, but to open up the size and space of the soundstage, leading to a more three-dimensional presentation of the music. Likewise, while it has been objectively proven that the average listener does not hear much above 12 kHz to 15 kHz, if a super-tweeter can cover from 8 kHz to over 40 kHz, it can have a major effect on overall system performance.
The subject of this review is the ENIGMAcoustics Sopranino electrostatic super-tweeter, which retails for $3,690 per pair. ENIGMAcoutics is the first company to produce, through a licensing agreement with the Taiwanese Industrial Technology and Research Institute of Taiwan, a self-polarizing electrostatic diaphragm that does not need an external DC power supply. It is a gray, rectangular, horn-loaded electrostatic diaphragm. The diaphragm measures 4.75 inches wide by 3.5 tall, and the Sopranino's overall dimensions are 8.15 inches high by 7.6 wide by 8.15 deep, with a weight of six pounds. The diaphragm is enclosed in a beautiful case of white, crystal-like glass, with a layer of felt on the bottom to protect your other speaker from being scratched when you place the Sopranino on top of it. Behind the Sopranino are a pair of WBT binding posts, a high/low gain switch, and a rotary crossover dial that can set the crossover point at 8, 10, or 12 kHz. For a quick, easy setup, you use a short speaker wire to connect each Sopranino to the back of your speaker's binding posts, match the gain of the speakers, and experiment with which crossover point gives the greatest positive effect without causing harm to the overall performance of the speakers.
Over a long time span, I used the Sopranino super-tweeter with seven different speakers in three different systems. Matching the gain level was always quite easy. With all the speakers I auditioned, the Sopranino with the 12-kHz crossover point had very little effect overall. When I would lower the crossover point to the 8-kHz level, it produced some positive sonic changes; however, it slightly took away some transparency in the upper midrange, possibly due to having too much overlap with the main speaker's drivers. The go-to crossover level that produced the best positive results was 10 kHz on all the speakers in the survey. For speakers using ribbon or AMT tweeters, like my Lawrence Audio Cello and Mandolin speakers, the benefits were quite slight in terms of air around the players in the soundstage. When used with speakers that use a more common dome tweeter, regardless of which material it was composed, the effects were much more noticeable. These included micro-dynamics and details that were more easily heard, an enlarging of the height and depth of the soundstage, and the creation of more space and air around individual players within the soundstage. My conclusion was that speakers having a tweeter with excellent high-frequency extension over 30 kHz and a wide radiating pattern derive very little benefit from the Sopranino super-tweeter. Speakers that start to roll off in the frequency region under 30 kHz are positively augmented by the Sopranino.
Click on over to Page 2 for the High Points, Low Points, Competition and Comparison and Conclusion . . .