Apex III technical information

The ultimate floor-standing tower for high performance audio and home theater applications!

With four CSS SDX7 6.8" mid-woofers, three FR125S midrange drivers and a single RAW Acoustics RA104.5 ribbon tweeter combined in a four-way design and housed in a slim tower, the Apex III is a real aural force to be reckoned with. Best of all, it is video shielded, so it is perfectly suited to high-resolution multi-channel audio and home theater. No longer must you compromise between audio and home theater: the Apex III is equally adept at both roles.

"Statement" speakers are rarely inexpensive, and the Apex III is no exception. It combines the sheer dynamics of large horn systems with the smooth sound and detail available only from conventional direct radiators. Add the pin-point imaging and soundstage depth found in small monitors to the equation, and you're almost where the Apex III takes you.

Bass

The Apex III starts with a rock-solid foundation: a quartet of CSS SDX7 6.8" mid-woofers, mounted in a net total of 4 cubic feet and tuned to 26 Hz with a large, rear-terminated slot vent. Thanks to their XBL²™ motors, these drivers are simply unmatched in clean output, bandwidth and dynamics in any size below 10" in diameter. This quartet has as much swept volume as most high-end, high-excursion 12" drivers, so a true subterranean bottom end is easily achieved. And because the woofers are small, the visual presentation is not compromised: the cabinet is slender and well proportioned.

Midrange and treble

Crossing over at 500 Hz to a pair of the phenomenal FR125S midrange drivers, the performance continues right through the critical midrange frequencies. The FR125S units are unrivalled as wide-band drivers; relieving them of the first decade of sound is paid back richly. Midrange detail and clarity are startling, dynamics are uncompressed and stunning, neutrality is guaranteed.

Above the FR125S mids sits a custom ribbon tweeter, measuring a scant 19 mm wide and 60 mm long, handling the top two-plus octaves starting at 4500 Hz. The RA104.5 is up to the task of mating with the drivers covering the bottom seven-plus octaves, and provides the right level of detail, air and immediacy to finish the overall sonic presentation.

Rear ambience driver

Mounted at the top of the rear is a single FR125S, run full-range. Attenuation is by a single 8 ohm 100 watt L-pad, which lets you dial in the desired amount of ambience. Unlike most ambience circuits, which contain just a tweeter, this is a true 100 Hz to 20 kHz ambience solution, creating one of the most holographic and exacting sound stages possible.

Crossover and cabinet

Blending it all together is the key. Just as a proper blend of spices and ingredients brings a gourmet dish together, the crossover is the heart of the matter: the best drivers in the world are wasted if the crossover does not integrate them as a cohesive unit. This crossover is not a simple textbook solution, but a fully engineered and voiced design.

Containing these drivers is a robust, well-braced and attractively proportioned cabinet. Standing 54" tall, 17" deep and just 10" wide, the Apex III is at home in nearly any environment. The drivers are arranged in a WMTMWWW configuration, with good symmetry and close driver spacing. The rear-firing driver is at the top and the rear-firing port at the bottom. Plenty of bracing keeps box vibration to an absolute minimum: the largest unbraced area is less than 1 square foot.

Response and impedance

The frequency response is an amazing ±1 dB from 60 Hz to 16 kHz. Anechoic bass is 3 dB down at 24 Hz. In-room bass extension is typically to 20 Hz, while the top end extends past 30 kHz: true acoustic bandwidth beyond the limits of audibility.

The impedance is smooth and free of glitches, indicating a well designed and damped enclosure. A minimum of 3.8 ohms is seen at 300 Hz; over the audio band the impedance averages 6 ohms, so it is compatible with nearly any amplifier.

Driver complement

4 × Adire Extremis 6.8" mid-woofers; 3 × FR125S wide-band drivers; RAW Acoustics RA104.5 ribbon tweeter

Crossover design

tweeter 3rd order, blended to a 1st order midrange, with a 2nd order network on the woofers

Frequency response

26 Hz – 30 kHz ±3 dB anechoic; 20 Hz – 30 kHz ±4 dB typical in room; F10 17 Hz

Sensitivity

88 dB SPL @ 2.83 Vrms at 1 m

Impedance

6 ohms nominal; 3.8 ohms minimum at 300 Hz; 25 ohms maximum at 20 kHz

THD

less than 3% at 99 dB SPL over the rated frequency response

IMD

less than 0.05% at 99 dB SPL over the rated frequency response

Recommended power

amplifiers rated from 50 W to 250 W into 8 ohms

Size

10" W × 17" D × 54" H