Pioneer S-2EX-W review

Pioneer's various S-EX models are certainly very serious speakers indeed, in no small part because they use drive units based on the legendary TAD units made by Pioneer's pro-audio division, Technical Audio Devices.

Since the days of Laserdisc, Pioneer has been a key player on the home cinema scene, and visitors to Sound & Vision shows over the years may well have been reduced to quivering wrecks by a complete multichannel S-EX surround sound system in full flight.

Floorstanders, centre-front dialogue, subwoofers and standmount speakers all share similar driver technology, similar enclosure construction and, of course, similar styling and presentation.

The build

The Pioneer S-2EX-W is a big and decidedly hefty three-way standmount. Unfortunately, it has also become a rather expensive one recently, as the plummeting value of sterling has led to a dramatic price rise, from the £3,500 per pair we thought the speaker cost when this review was originally commissioned to a wallet-hammering £5,200 per pair.

At a not inconsiderable 28kg, a weightlifting belt is advisable when unpacking and lifting each speaker onto a stand. Although it's well suited to the normal 60cm-high stand, the model's substantial footprint means you'll need one with a relatively large top surface.

Furthermore, the curved shape really suggests that Pioneer's own matching stand is probably the best choice. Designed to complement the look of these impressive speakers, the proprietary stands are available at an additional cost of £1,000 per pair.

The technology behind these speakers is hugely impressive. Pioneer's TAD division is (of course) responsible for the two high-tech drive units. However, appearances can be deceptive, as this is actually a three-way design. The midrange and treble are handled by a coaxial unit, which combines a 140mm midrange driver with a 35mm tweeter.

Pioneer implies exclusivity for this so-called CST (Coherent Source Transducer) technology, though the similarity to Kef's 20-year-old Uni-Q approach is hard to ignore. A 180mm unit, reflex-loaded by a substantial flared front port, supplies bass.

With nominal crossover frequencies at 400Hz and 2kHz, each of these drive units is expressly designed for its operating range. The driver frames are open and unobstructive, while compact neodymium magnets make their own contribution to avoiding reflections.

The 180mm bass driver has a very large (65mm) voice coil and a 140mm cone/dome diaphragm. For extra strength, the latter is formed from a single piece of woven Aramid matrix (not unlike Kevlar), while the surround is a damped-cloth concertina affair.

The midrange diaphragm is a magnesium-alloy cone 110mm in diameter, while the 35mm dome tweeter is formed from that stiffest of all metals, beryllium.

By placing the tweeter down in the 'throat' of the midrange cone, the two diaphragms can be time-aligned in terms of the distance from listeners, while the shaped concave baffle sets the rather deeper woofer somewhat ahead of the CST unit, to bring it into time alignment too.

No mention is made of the crossover network or its components in the propaganda, which is a little surprising, though the impedance trace looks very complex. Twin terminal pairs are mounted directly through the wooden back and are supplied with high-quality wire links.

Neodymium magnets are light as well as compact for their power, so it's likely that much of that intimidating 28kg is down to the hefty enclosure, which is immensely strong and tough. The curved sides and back are constructed by laminating together many thin layers of MDF and the total thickness apparently varies between 30mm and 100mm.

The surface is covered in good-quality satin-finish real-wood veneer – very dark, almost black, on our samples, though a high-gloss beech is also available.

Performance

Although it's been a busy month for speaker reviewing, with no fewer than eight models lining up for attention, this Pioneer stands head and shoulders above the others, well justifying its elevated price through an impressive collection of pluses and very few negatives.

Though basic, the measurements are as usual rather revealing. The far-field in-room power response is exceptionally flat and neutral, give or take the odd room mode.

However, in view of the size of the enclosure, the rather average 88dB/2.83V sensitivity (somewhat better than Pioneer's figure, probably due to differing measurement conditions) and the quite demanding impedance characteristic, the bass isn't particularly well extended, registering -6dB at 37hz under our in-room conditions.

While the broad midband, presence and much of the treble are notably flat, even and quite smooth, things look rather untidy between 10kHz and 20kHz, due to the coaxial layout.

Although the in-room responses do indicate clear-of-wall siting, the bass alignment is quite dry, so the speakers could be set a little closer to a wall without causing problems.

The bottom octave is audibly largely absent, partly because the bass end of this speaker is unusually clean and clear of any significant coloration. It operates with impressive grip, drive and a real sense of purpose that underpins the rest of the range with enthusiasm, agility, drama and authority.

This is a genuine monitor in every sense of the word. It doesn't do sweet and it doesn't do 'easy on the ears'. It tells it like it is with an efficiency that some might find a little too ruthless, but which this listener interprets as a refreshing honesty.

As a monitor it's exceptionally effective, due to its superb open neutrality, wide dynamic range, fine grip and superb low-level resolution. It demonstrates superior dynamic linearity and tracking across a wide range, always seeming to maintain proper contrasts from lowest to highest levels, whatever the volume-control setting.

Voices demonstrate fine expression and articulation, making it easy to tell specific voices and their individual accents apart, and communicating their intentions and inflections very accurately and effectively.

Total coherence does seem to be slightly compromised, due perhaps to a little untidiness towards the top of the audio band, but timing is nonetheless very good and stereo images are beautifully focused, with a fine rendition of depth and ambience.

The lack of deep bass didn't seem too much of a problem in isolation, but when the Pioneers were shipped for photography and replaced by a much larger (and more costly) pair of pro monitors (PMC IB2is) offering considerably more deep bass, the improvement was obvious and beneficial, the extra weight and scale somehow making the whole listening experience more relaxing, without adversely affecting the musical enjoyment or the subtle detail.

The S-2EX does, therefore, have its limitations. It needs a powerful, high-quality amplifier and does lack a little warmth and welly low down.

But at the end of the day, its powers of analysis are prodigious and its ability to enable unfamiliar music forms to communicate effectively is exceptional. It goes without saying that there's a great deal to like here.