Unity Audio Signature 3 Page 2
The second sample of the Signature 3's bass quality was about the same as the first pair, maybe a little smoother in the upper bass. It remained smooth all the way to the cutoff point, still about 55Hz. With Simple Minds' latest, Good News from the Next World (Virgin 39922 2), the lack of low bass was a little unsatisfying. This is a bright recording, so it sounds lightweight on its own. With the Signature 3 it sounded even more lightweight than with the other speakers in this review, which will all go at least another half-octave down in frequency.
This lightweight balance is the Signature 3's only major drawback. It was more of a casualty on rock music like this, which relies so much on that driving beat. This shortcoming was partially offset by the high quality and tightness of the upper bass, however. Everything did have a nice rhythmic feel, if not a sense of low-end heft.
The Signature 3s provided me with plenty of detail, falling short of what I heard with the Thiels and B&Ws, but not by much. I prefer listening to even mediocre recordings like Journey's Greatest Hits on a very revealing system. Hits they sure arethey hit you over the head with the harsh sound of too much electronic processing. I'm willing to take a few blows if I must, for the sake of hearing more of what the musicians are doing. Correctly, the Unitys didn't pull any punches.
The Signature 3s, however, sounded just too bright on the Journey Hits album, which is, at any rate, a collection of too-bright recordings. The speakers had their usual hazy, too-prominent treble, yet I was still able to listen past the recording flaws and enjoy the music. Here, again, the lack of anything resembling low bass was a liability. I didn't miss it too much unless I was listening to rock, and I bring it up because I really can't find too many other things to complain about with these speakers. I think whether or not you'd rule them out as candidates because of their limited LF extension really depends on what type of recordings you listen to the most.
Though the Unity Audios gave a generally spacious presentation, with a subjectively large amount of ambience, their imaging was not as pinpoint as I'm used to. The ambient decay of the new samples seemed to be a little better than with the older versions, more precisely defining the exact spaces where the recordings took place. They tended to foreshorten the depth associated with instrumental locations, although not to the detriment of the music. In spite of this, the recording venues did have a nice large feel, partly because of the rear woofers' sound spreading around without bound. Individual instruments were not placed quite as precisely as I've heard with other speakers. The (quasi) dipole design has tradeoffs, but I definitely enjoyed the benefits of this method of loudspeaking.
I briefly tried driving the Unitys with the NAD 2100X, to get an idea of the effect of a low output impedance on their sound. The midrange and treble seemed just a little worse in terms of balance, but the difference was very small. The bass seemed a tiny bit fuller. Kathy Grost of Unity Audio told me that the more recent Signature 3s have a fairly flat impedance curve, so that their balance should not change drastically when changing amps. It sounded to me as if that was the case. However, sometimes even a small change in balance can be important, so I recommend a careful audition before pairing these speakers with one of those crazy billion-ohm output impedance single-ended amplifiers.
The Signature 3s passed the Greenberg Memorial Loudness Test without blowing upas, given their maximum power rating, you'd expect them to. I think 300W might be a little optimistic, but I didn't get quite that carried away, so I wouldn't know for sure.
I do think both the Unity Audio Signature 3 and the Thiel CS1.5 are worthy of recommendation for listening to any kind of recording. And, like any two high-end components that you might hit if you threw two rocks in the air, they have different balances of strengths. The Signature 3 will play louder, but the 1.5 will go lower in the bass. The CS1.5s' imaging is more pinpoint-accurate, but the Signature 3s give a more enveloping sense of space. The Signature 3 presents more midrange detail, but the '1.5 has a flatter frequency response.
Come to think of it, both the Unity Audio and the Thiel have a lot in common (in addition to the loudspeaker ladder thing). They both have a bit of an unforgiving treble. They both are very detailed and will reveal the quality of anything they're matched with. Also, they both have tight and tuneful bass.
Which did I prefer, after all of my auditioning? For me, the nod has to go to the Thiel CS1.5. I felt it was a little more accurate in some respects, and the bass extension was a necessity given the amount of rock music I listen to. I certainly enjoyed my time listening to the Signature 3, though, and so might you.
For the record, I marginally preferred the sound of the B&W Matrix 804 (footnote 2) over those of the other three speakers. This surprised me a little, since the B&Ws are four years old. Still, I've gotten some really fine replacement woofers under warranty from B&W. As you can imagine, I was relieved: it meant that dancing the Buy/Sell Tango was still way off in my future.
Footnote 2: Reviewed by TJN in November 1991, Vol.14 No.11, p.150.