Infinity Kappa 9 Floor standing speakers

Far too often, advances in high-end audio simply bring greater sophistication and greater expense. Indeed, as top audio designers focus on equipment whose price is no object, the end result is often a product that most audiophiles can only dream about. The Infinity 9 Kappa speaker system is a major exception.

The 9 Kappa can hardly be called cheap; after all, a pair of these speakers does cost $2,698. Nonetheless, in designing the 9 Kappa, Infinity took advantage of the lessons learned in building the $45,000 IRS Series V and the Beta, Gamma, and Delta group; as a result, the 9 Kappa introduces new driver and crossover technology at a much more affordable price. It also offers overall performance superior to that of the older Infinity RS-1B-a loudspeaker system I liked enough to use as a reference for several years.

The Technology

The Infinity 9 Kappa is a floor-standing speaker system measuring 59-1/2 inches high, 21-1/2 inches wide, and 8 inches deep. Its frequency response is rated at 29 Hz to 44 kHz, ±3 dB. It uses six drivers aligned vertically on its front panel; the bandwidth of each has been carefully limited to optimize performance in a given area of the frequency spectrum. These front-panel drivers include a SEMIT supertweeter, an EMIT tweeter, a 3-inch polypropylene dome upper midrange, a 5-inch polypropylene/graphite dome lower midrange, and two biampable 12-inch polypropylene/graphite woofers which are adapted from those used in the Infinity IRS. In addition, to provide added ambience in the overall radiation pattern, the 9 Kappa has a rear-firing EMIT tweeter, and there is back (or bipolar) radiation from the 3-inch upper midrange driver.

There simply isn't space to go into all of the technical details regarding these drivers, but it is worth noting that the new SEMIT and EMIT have much lower mass than the EMITs Infinity has used in the past and seem to produce a "faster" and more detailed sound. The new 5-inch polypropylene/graphite speaker operates from 90 to 700 Hz and ensures an exceptionally smooth transition from the bass to the midrange-an area where I heard difficulty in the RS-1B. Further, the woofers have exceptionally stiff, lightweight cones and heavy, rigid cast frames.

The crossover is an advanced, passive five-way design, with crossover frequencies at 90 Hz, 700 Hz, 5 kHz, and 10 kHz. Taking note of the latest high-end wisdom about passive components, it uses polypropylene capacitors, hard-soldered connections, high-purity wire, and low-noise potentiometers. On the rear of the speaker are level controls for each driver except the woofers, allowing exceptionally flexible tuning of the system to match a given room and amplifier.

The cabinet does more than give this very large speaker system the appearance of being relatively small and attractive; it also shows exceptional attention to edge diffraction and boundary reflections. The speaker grille is mounted on short rods that allow it to stand off the surface of the speaker cabinet, and it does not spoil the dispersion of sound with internal ridges that can limit the sense of air and the quality of imaging.

Sound Quality

Admittedly, whenever an expensive new speaker system comes onto the market, it's likely to have new drivers and to be accompanied by impressive claims about its technology. Few new speakers, however, pay off as well as the 9 Kappa in terms of improved sound quality. This becomes clear when the speaker's performance is examined in detail.

The top octaves combine exceptional detail with an excellent feeling of openness and air. Infinity's previous EMIT designs have performed well in this area, but they have not approached the speed and openness of ribbon designs. The 9 Kappa outperforms even the older Infinity IRS in this area. It rivals the most expensive ribbon speakers and outperforms every electrostatic I know of.

The strengths of the changes in Infinity's EMIT design become even clearer in the upper midrange/treble, the area between about 5 and 12 kHz. The 9 Kappa's strength of speed and detail is much more apparent in this region and affects virtually every aspect of voice and instrumental performance. The overall transparency is surpassed only by the most expensive ribbon speakers and by Infinity's latest IRS speaker, which uses a larger array of EMIT drivers. This transparency and superior resolution does come at a cost: It exposes any weaknesses in the electronics and source material used with the 9 Kappa. It also, however, sets the music free when you do have top-quality components and material.

The Infinity 9 Kappa does reveal some integration problems in the midrange, relative to a few top competitors. The best electrostatics and ribbon speakers seem slightly flatter and more natural in terms of overall cohesiveness and integration of the midrange, and several top-ranking cone systems are equally good. Nevertheless, there are no apparent discontinuities, and the midrange is still smooth and natural.

In the lower midrange and upper bass, the 9 Kappa errs on the side of life and excitement and avoids the slight "suck out" that exists in this region in many speakers-including the RS-1B. Further, careful adjustment of the mid-bass control allows you to get the natural warmth of instruments like the cello without overpowering the lower midrange. Few speakers can really reproduce the lower strings and woodwinds in a musically convincing form, and the 9 Kappa is one of them.

The upper and middle bass is very good. There is just a slight touch of overemphasis with proper adjustment of the mid-bass control, and this is not unpleasant with most music. Although the 9 Kappa has a relatively moderate capability to reproduce true deep bass and seems to begin losing some of its definition and detail around 60 Hz, its deep bass has surprising power and speed, considering the size of the 9 Kappa's enclosure. Most important, the power and frequency range of the bass are good enough to match the detail and extension of the 9 Kappa's treble without masking the midrange's detail. Most speakers, regardless of price, tend to favor one frequency extreme over the other. The 9 Kappa is a true full-range speaker.

With a good high-current amplifier, the 9 Kappa is capable of sufficient dynamic range to suit any lover of full-range orchestral music, grand opera, and heavy metal. Unlike many speakers, it also offers consistent performance from soft passages up to very loud ones. There is no sense of strain at high level, no loss of low level, and no shift in timbre.

Imaging is excellent-stable and naturally detailed from left to right without any loss of center fill. The image appears to extend beyond each speaker, to the left and right. The sound stage does not seem to "cluster" around each speaker, and depth is good to very good. The adjustments on the rear of the 9 Kappa allow you to vary the overall timbre and dynamics from "front row" to "mid-hall," although the apparent imaging will be determined largely by the miking of the original recording.

In terms of overall integration, the 9 Kappa meets a test most speakers fail: It sounds equally natural at moderate and high listening levels, and does equally well with solo vocals, chamber music, small jazz groups, choral music, and full orchestral music. If this test sounds easy, try it. The vast majority of speakers perform better at one listening level than another and make performance compromises that favor one type of music over another. The 9 Kappa is one of the few systems that offer musically credible reproduction with virtually any good source material.

Human Engineering and System Considerations

The Infinity 9 Kappa is relatively easy to place. Although it is definitely a "big speaker," it still is small enough to fit into most real-world listening rooms. It does benefit from every inch of space you can give it, relative to rear and side walls, but it performs well at distances as short as 3 feet from a room boundary. While bass performance is sensitive to placement relative to corners and the rear wall, the 9 Kappa was much easier to place than any true dipole speaker I've encountered, and relatively small adjustments in position were usually adequate to smooth the sound of the bass.

The imaging is broad and smooth in a wide range of listening areas, particularly if the speaker is parallel to a smooth rear wall surface or just slightly angled so that each speaker is aimed at a point about 2 feet behind the listening position. You can easily use a wide couch or several chairs at the listening position and still get an excellent sound stage, and the sound stage will remain acceptable over an even wider area. The driver configuration is also well chosen; the drivers are high enough to overcome the effects from most furniture and floor surfaces, and they provide a good vertical image without the need for major floor-surface treatment.

The speaker's rear adjustments are flexible enough to be useful without disturbing system cohesion or the balance between the drivers. In fact, I would strongly recommend setting every control except the mid-bass control somewhere between 11:00 and 12:00. The flat settings (around 2:00) sound too bright and hard in all but very absorbent rooms. As for the mid-bass control, I advise careful reading of the owner's manual and careful and prolonged experimentation. The mid-bass is an area where room problems are very apparent to the ear in terms of giving music too much or too little warmth. The 9 Kappa gives you the flexibility to get exceptional realism if you simply take the time to do it right.

The only practical problem you are likely to encounter is that you really will need a high-current amplifier if this speaker's bass performance is to equal its performance in the upper octaves. There is a switch that allows you to safely use lower current amplifiers- or those that can't survive low impedances-but the use of this switch has a cost: A loss of bass performance and overall system balance. Consult your dealer, or Infinity, to make sure that your power amplifier is fully compatible with the 9 Kappa.

Summing Up

I'm more than a little impressed with the 9 Kappa. It truly is much better than the Infinity RS-1B-although the RS-1B has been highly competitive with most other speakers and cost more than twice the price of the 9 Kappa. It is an extraordinarily open, natural, and dynamic full-range speaker system which offers the life and power that rock and jazz lovers like while preserving the realism and natural musical tone necessary to please voice and chamber music lovers. Its excellent, open dispersion ensures that it delivers this performance over a wide listening area, and it is stylish, to boot.

A few other speakers may offer more in terms of deep bass power and extension, overall smoothness and integration of the musical spectrum, or sound-stage size and impact. Even the most demanding audiophiles, however, are likely to agree that the Infinity 9 Kappa offers exceptional value as a high-end product. It is also an impressive demonstration that years of work in developing demanding and expensive high-end products can pay off in providing superior benefits to the audiophile at a substantially lower cost.

Infinity Kappa 9 Floor standing speakers photo