Pioneer S-1EX loudspeaker
One of the highlights of such annual events as the Consumer Electronics and Primedia Home Entertainment shows has been the demonstrations of loudspeakers from TAD, the professional division of Pioneer Electronics. Designer Andrew Jones is always generous in using recordings brought by visitors, and enthusiastic in explaining the technology behind these beautiful behemoths. Among these speakers' unique features are a beryllium dome tweeter mounted concentrically inside a beryllium midrange cone, and a cabinet built of stacked, carved horizontal sections, for incredible rigidity without using exotic materials or excessive mass. The concentric upper-range driver is a reminder that, some time back, Jones worked for KEF, where the coaxial UniQ driver was developed, but the materials and details of the TAD drivers are all new. While the TAD Model 1s are always good for musical and audiophile thrills, their price is in the upper five figures, which put them out of serious purchase consideration.
However, at the 2006 CES, I found Jones in the Pioneer room, just downstairs from the TAD room, demonstrating Pioneer's new EX speaker line, which is derived directly from the technology developed for the TAD products. That demo, of the stand-mounted S-2EX ($6000/pair), was very encouraging; the demo at HE2006 last May of the larger S-1EX ($9000/pair) convinced me that I had to get a pair for review.
Description
Some months later, two large transit cases, each the size of an armoire, appeared at my back door—along with Andrew Jones, who assisted in unloading them. That task was quite easy, and shortly I was alone with the S-1EXes.
Why they don't bear the TAD badge and its attendant cachet rather than the Pioneer logo with a fancified EX modifier is a long story that involves Pioneer's worldwide marketing decisions rather than any effort to distance themselves from the TAD name. Nonetheless, we've seen many mass marketers try to invade the High End with worthy products, only to fail because the typical audiophile couldn't bear to have a Sony or a Samsung nameplate. Heck, even the Japanese big three auto makers, Honda, Toyota, and Nissan, invented new names and distribution channels in recognition of the need to differentiate their high-end models from their regular lines. Let's hope that the S-1EX will be the exception to the rule; it will be sold through "selected" Pioneer EX dealers and is not simply a gussied-up mass-market box. It's a genuine effort to offer cutting-edge speaker technology at an affordable price. Of course, affordable is highly subjective, but an order-of-magnitude reduction in price from the TAD-1 is significant on anyone's scale.
The S-1EX is a handsome black column with a subtly complex shape. Its cross section is almost trochoid—that is, its curve is generated by a point on the radius of a circle or the radius extended as the circle rolls on a fixed straight line—and the front and sides are gently convex. Jones maintains that the use of curved construction results in greater stiffness than would result from flat panels of the same thickness. The thickness of the panels ranges from 3" on parts of the front to 1.25" on the sides, which are built up from 1/8"-thick layers that are curved before being laminated together. The S-1EX comes mounted on a heavy base plate whose adjustable feet give the speaker a wide stance. With its feet flat on the ground, the cabinet leans slightly back and is absolutely stable. In addition, almost the entire front of the cabinet is deeply scooped out from top to bottom, with the drivers mounted in a vertical arc. This is done so that each driver is equidistant from and aimed directly at the listener.
And what special drivers these are! The coaxial tweeter-midrange—or, as Pioneer calls it, the Coherent Source Transducer (CST)—consists of a beryllium-dome tweeter that shares a dual-gapped neodymium magnet with a magnesium-coned midrange unit. (The TAD drivers use beryllium, with its high ratio of stiffness to mass, for both the tweeter and midrange.) The coaxial arrangement means that these two drivers essentially act as a single driver that provides controlled and symmetrical radiation for all frequencies from the low hundreds up to 100kHz. The S-1EX also has two 7" woofers with cones made of layers of aramid, carbon fiber, and polypropylene, with neodymium magnets and diecast aluminum chassis—all features of the TAD system as well. The complex, composite crossover uses series and parallel elements to divide the frequencies among the drivers, control their in-band frequency responses, and ensure that the overall system presents a sensible load to the amplifier.
To sum up: The S-1EX has four drivers in three chassis, vertically arranged on the front panel, below them an artfully sculpted 5" port. At the bottom of the rear panel are nice biamp terminals. There are no tone controls or doohickeys.
Sound
My first impression of the S-1EX was of clean, balanced sound, with the exception of some lumpiness in the bass that demanded that I experiment with the speakers' positions. Andrew Jones assisted with this, and before he left, the S-1Exs were positioned to his liking. However, I now thought they lacked a little in the bass. Over the next week or so, I moved them a bit farther from the sidewalls and toed them in a bit more to reach what sounded to me like smooth neutrality. I listened to them this way for quite a while before realizing that, when listening, I was always sitting much more erectly than mere alertness required. I placed a 5/8"-thick board under the rear feet of each speaker base so that the speakers themselves sat a bit straighter. (I could have adjusted the feet and gotten the same effect, but I'd already packed the provided tool away with the shipping cartons.) At my listening distance of about 14', this placed the axes of the CST drivers exactly at the level of my ears. That was it!
At every musical task I set it, the S-1EX was simply outstanding. Most important, it was devoid of any identifiable tonal coloration through the mid to high frequencies. That, coupled with its great transparency and crisp transients, made it sound more like a full-range planar than a conventional box speaker. Like planars, it seemed to be able to throw the music into the room rather than let it expand backward behind the speaker plane. Unlike most planars, it was as good with the precision imaging of a single instrument—a solo violin, say—as with a full orchestra or choir. Whether the violin was off to the side, as in the opening solo in Fritz Reiner and the Chicago Symphony's recording of Rimsky-Korsakov's Scheherazade (SACD/CD, RCA Living Stereo 66377-2), or dead center, as in Julia Fischer's spectacular new performance of Tchaikovsky's Violin Concerto with Yakov Kreizberg and the Russian National Orchestra (SACD/CD, Pentatone PTC 5186 095), it was both dead stable in position and full-bodied in tone.
The S-1EX's large soundstage representation was wide and tall, though less deep than a warmer, richer speaker would make it, and at first I missed that depth. However, I have no way of knowing exactly how far behind the orchestra the choir stood during the recording of, say, Sibelius' Kullervo, by either Sir Colin Davis and the London Symphony (SACD/CD, LSO Live LSO0574) or Robert Spano and the Atlanta Symphony (SACD/CD, Telarc SACD-60665). In the former, the entry of the men's chorus in Part 2 is thrilling, the deep voices spread broadly across the back of the soundstage just behind the detailed and somewhat sleek strings and winds. The Spano at first seemed even more spectacular in its greater depth for both chorus and orchestra, but over time I realized that the prices paid for that depth were wind placements that were less than natural and slightly muted upper strings. The Pioneers made explicit all the spatial and tonal differences between these two recordings while also making both quite satisfying. With such variables, it was hard to find fault with the S-1EX.
With smaller-scale recordings, the S-1EX did everything I asked. In fact, it was eminently clear that Patricia Barber's voice on Modern Cool (SACD/CD, Mobile Fidelity UDSACD 2002) should not be softer or louder than one specific volume setting, and at that setting the piano, bass, and all the stars were in perfect alignment for a stunningly realistic presentation. Solo guitar, too, was clean and ripe, with all the details of fingers on strings in appropriate measure. In fact, I found myself gravitating toward music rich in transients so that I could revel in the Pioneer's abilities to reveal all the details.
Listening to a new reissue of the 1973 Decca/HEAD recording of Roberto Gerhard's brilliant and blistering adaptation of Camus' The Plague, with speaker Alec McGowan, Antal Dorati, and the National Symphony Orchestra and Chorus (CD, Explore EXP0005), I was continually startled by the intimacy of the vocal parts and the power of the orchestra. McGowan's matter-of-fact narration was chilling—through the S-1EXs, he seemed to speak to me from a seat in my own room, as all the plague-driven panic and chaos raged outside. The S-1EX's midrange and treble are great.
The S-1EX also had excellent bass extension and detail, and, when called on, could deliver a terrific wallop. It did sound a bit bass-shy at times, but that was due in part to what I heard as a highly damped tuning of the drivers and cabinet. This contributed in no small measure to the speaker's overall transparency and openness throughout the entire audioband—I wasn't distracted by any spurious muddiness or boom. For example, wide-range organ recordings sounded glorious, with granitic, stygian pedal tones. It was only when I listened to low timpani and bass drums that this overdamping seemed to dull the impact and presence a wee bit. All I had to do was transfer all bass below 50Hz to a JL Audio f113 subwoofer and it was clear that the Pioneers could do a little better. Sure, this wasn't fair—the JL is a dedicated bass transducer with an adaptive room equalizer that has improved the bass of every speaker I've used it with. Still, the best is the enemy of the good, and the S-1EX is better in the bass than underdamped speakers that spew woolly bass all around the room.
A comparison with my resident B&W 802D speakers was interesting. Central imaging and transparency were equally good. The Pioneers threw a wider, more forward soundstage, but one more limited in depth than the B&Ws'. Joel Fan's piano on his eponymous recital disc (CD, Reference RR-106) was pearly clear and fairly forward through the Pioneers, but I heard more of the instrument's body wood and more of the ambient space with the B&Ws. The Pioneer give the impression of greater transient quickness and brilliance, but a careful comparison suggested that this might have been the consequence of its overall balance, which can seem tilted toward a treble balance higher than the B&W's. Despite all these impressions, Julia Fischer's violin sounded remarkably similar through both speakers.
I did most of my listening with a pair of Bel Canto REF-1000 monoblocks that, fortuitously, I'd recently installed in my system. Andrew Jones had used this class-D amplifier for his impressive demos at HE2006, and we agreed that the match was symbiotic. Although I tried other amps with varying degrees of success, I kept coming back to the Bel Cantos. The Classé CA-3200 and the Mark Levinson No.433 provided more midbass slam without adding any bloat, and sweetened the extreme treble, but the basic honesty of the S-1EX's midrange remained unaffected. The downside of both the conventional amps was their emphasis of the S-1EX's slightly puddingy reproduction of bass drums and low electric bass. This was probably the only flaw in the Pioneers' otherwise faultless performance, and mating them with the Bel Canto amps minimized it with no further damping or rolling-off of the bass.
Conclusions
I never bought into "trickle down economics" before, but Pioneer and Andrew Jones have applied the audio technology they learned in making the TAD Model 1 to a much less expensive speaker that has retained a disproportionate amount of the TAD's performance. Sure, $9000 is not pocket change. On the other hand, the S-1EX is fully competitive with higher-priced speakers that have spent time in my listening room, such as the B&W 802D ($12,000/pair) and the now-discontinued Revel Ultima Studio ($15,000/pair)—and with anything I've heard in demos. In regard to ease of placement in a domestic room not exclusively dedicated to listening, the S-1EX surpassed all other speakers I've used. This means that anyone who buys the Pioneer is more likely to enjoy optimum results than with more finicky speakers.
If you've read this far, you know that I love the Pioneer S-1EX. It is a full-range speaker with great transparency, dynamic potency, and truly neutral tonality. The speaker's ease of placement and setup are aided by its ability to immediately and easily reveal how it is affected by changes in position—when the Pioneers are in the right places, you'll know it. Then you'll stop thinking about the S-1EX and all its technological features, because you'll be listening to the music. Ladies and gentlemen, we have a winner.
