One of Kawai’s most important innovations is the use of ABS Styran plastic in the manufacture of action parts. More than 40 years of use and scientific testing have shown this material to be superior to wood for this purpose. ABS does not swell and shrink with changes in humidity, so actions made with it are likely to maintain proper regulation better than wood actions. The parts are stronger and without glue joints, so breakage is rare. These parts are present in every Kawai piano. In the current Millennium III action found in some models, the ABS is reinforced with carbon fiber so it can be stronger with less mass. Having less mass to move (that is, less inertia), the action can be more responsive to the player’s intentions, including faster repetition. Certain contact surfaces on the action parts are also micro-engineered for ideal shape and texture, resulting in a more consistent touch. Although it took a number of years to overcome the idea that plastic parts must be inferior, there is essentially no dispute anymore among piano technicians on this subject.

Kawai’s vertical piano offerings change frequently and are sometimes confusing. At present there are three basic series of Kawai verticals. The console series begins with the 44½" model 506N, a basic entry-level console in an institutional-style cabinet (legs with toe blocks). Model K-15 is a 44" version of this in a continental-style cabinet (no legs), and model 508 is a 44½" version in a simple furniture-style cabinet (freestanding legs). Model 607 is the same piano in a fancier furniture-style cabinet. All have the same internal workings. The action in this series is slightly smaller than a full-size action, so it will be slightly less responsive. However, it is more than sufficient for beginner or casual use.

Kawai has replaced both of its former studio models, the UST-7 and UST-8, with the 46" model UST-9, made in Indonesia. This model has the stronger back of the UST-7, rather than that of the UST-8, which was not known for its tuning stability. The UST-9 also contains the Millennium III action; an angled, leather-lined music desk to better hold music; and a stylish, reinforced bench. The 46½" model 907 is essentially the UST-9 in a fancy, furniture-style cabinet.

Kawai’s K series of upright models has been updated in 2014, and the model names have been changed. The former K-2, K-3, K-5, K-6, and K-8, all sold in North America, have become the new K-200 (45"), K-300 (48"), K-400 (48"), K-500 (51"), and K-800 (53"). The K-400 is internally the same as the K-300, but its cabinet includes a grand-piano–style music desk (formerly available only with the K-8) and a folding, low-profile fallboard. The K-500 — at 51", two inches taller than the old K-5 — has been extensively redesigned internally, with longer bass strings, a larger soundboard, and a redesigned cast-iron plate. Several of the new K-series models are available in the AnyTime (ATX) series as silent/hybrid pianos. See the article on Hybrid Pianos for details.

As before, all K-series models include Kawai’s Millennium III actions, made with carbon-fiber composites. The hammers in all models are now made with underfelt and mahogany moldings, which Kawai says improves the responsiveness of the action and the tonal sustain. All models have redesigned, tapered soundboards for improved tonal response; double-braced and steel-reinforced keybeds to prevent warping and flex; and come with slow-close fallboards and adjustable benches. The K-500 and K-800 both feature Kawai’s Neotex ivory-substitute key material, and the K-800 comes with a sostenuto pedal. The K-series cabinets have been redesigned for a sleeker, more modern appearance.

Kawai makes two series of grand pianos: GX and GL. The GX line (formerly RX; see below), which is sold in North America in a version known as the BLAK series, is the most expensive and has the best features. It is designed for the best performance, whereas the GL series is designed more for efficiency in manufacturing, with fewer refinements. All the GX pianos feature a radial beam structure, converging together and connected to the plate using a cast-iron bracket at the tenor break. This system makes for a more rigid structure, which translates into better tone projection. The soundboards in the GX models are tapered for better tonal response; and the rims are thicker and stronger than in the GL models, and are made of a blend of open- and closed-pore hardwoods to improve the tone. The Kawai Millennium III actions used in both series now have hammer-shank stabilizers, designed to retain power by keeping the shank from wavering under a heavy blow. All GX pianos have agraffes, duplex scaling, lighter hammers (less inertia), and Neotex synthetic ivory keptops; and come with a slow-close fallboard. The GX grands get more precise key weighting, plus more tuning, regulating, and voicing at the factory. The cabinetry is nicer looking and of better quality than that of the GL series pianos, with the polished ebony models in the new BLAK series receiving a UV-cured, scratch-resistant coating on the music rack.

In 2013, the GX BLAK models replaced the previous RX series — see our review in the Spring 2014 issue. The changes from RX to GX include a pinblock that is fitted to the plate flange and more securely attached to the case for better tuning stability, and the front stretcher has been made thicker, stiffening the structure, and thus both conserving tonal energy and contributing to tuning stability. The GX rims use alternating layers of two different hardwoods, one chosen for tonal power, the other for warmth. There have also been some changes to the scale designs and soundboard taper.

In the fall of 2015, Kawai consolidated its GM and GE piano lines into a single, new GL line of models: GL-10 (5'), GL-20 (5' 2"), GL-30 (5' 5"), GL-40 (5' 11"), and GL-50 (6' 2"). The GL models share some important features with the higher-end GX models: Millennium III action with hammer-shank stabilizers, agraffes, stronger pinblock/stretcher design, longer keys, full sostenuto pedal, and soft-close fallboard, among others. However, the GL models have a single-wood-variety hardwood rim, rather than the blended hardwoods of the GX series; a solid rather than a vertically laminated bridge, without cap; acrylic rather than Neotex keytops; a simpler beam structure in the smaller models (GL-10/20/30); and a simpler cabinet design and less elaborate interior finishing. The GL-20/30/40/50 models are all built in Japan; the GL-10 is made in Indonesia. The inclusion of several GX-level features makes the GL-10/20 models significant steps up from the discontinued GM models.

Kawai’s quality control is excellent, especially in its Japanese-made pianos. Major problems are rare, and other than normal maintenance, after-sale service is usually limited to fixing the occasional minor buzz or squeak. Kawai’s warranty service is also excellent, and the warranty is transferable to future owners within the warranty period (a benefit that is not common these days). The tone of most Kawai pianos, in my opinion, is not as ideal for classical music as some more expensive instruments, but when expertly voiced, it is not far off, and in any case is quite versatile musically. In part because the touch is so good, Kawai grands are often sought by classical pianists as a less-expensive alternative to a Steinway or other high-end piano. There is also a thriving market for used Kawais.

The Shigeru Kawai line of grands represents Kawai’s ultimate effort to produce a world-class piano. Named after Kawai’s former chairman (and son of company founder Koichi Kawai), the limited-edition (fewer than 300 per year) Shigeru Kawai grands are made at the separate facility where Kawai’s EX concert grands are built.

Although based on the Kawai RX designs, the Shigeru Kawai models are “hand made” in the extreme. Very high-grade soundboard spruce is air-dried for multiple years, then planed by hand by a worker who knocks on the wood and listens for the optimum tonal response. Ribs are also hand-planed for correct stiffness. String bearing is set in the traditional manner by planing the bridges by hand instead of having pre-cut bridges pinned by machine. Bass strings are wound by hand instead of by machine. Hammers are hand-pressed without heat for a wider voicing range, and the hammer weights are carefully controlled for even touch. Hammer shanks are thinned along the bottom so that their stiffness is matched to the hammer mass. These procedures represent a level of detail relatively few manufacturers indulge in.

In 2012, Kawai updated the Shigeru Kawai grands, changing the cabinet styling and some of the pianos’ construction features. The inside of the rim is now finished with bird’s-eye maple veneer, and the round legs have been changed to straight legs with brass trim. The rim itself is now made of alternating layers of rock maple and mahogany, which Kawai says provides more power without losing warmth in the tone. The structure at the front of the piano has been made stronger, and the beams underneath are now made from spruce instead of the laminated mahogany Kawai uses in its other models. The keys have been lengthened for a better touch, especially on the smaller models.

Each buyer of a Shigeru Kawai piano receives a visit within the first year by a Kawai master technician from the factory in Japan. These are the same factory technicians who do the final installation of actions in pianos, as well as the final voicing and regulation. According to those who have watched them work, these Japanese master technicians are amazingly skilled. Because the Shigeru Kawai pianos have been on the market only since 2000 and in very limited quantities, many piano technicians have yet to service one. Those who have, however, tend to rank them among the world’s finest instruments, and Shigeru Kawai pianos are often chosen by pianists participating in international piano competitions.