EPIQUE by Dayton Audio

With more than 20 years of experience offering high-quality audio products, Dayton Audio is pleased to introduce its newest line of premier audio products: EPIQUE. The new EPIQUE line offers unique, attractive and top-performing products with the trusted quality and reputation that you’ve come to expect from Dayton Audio.

EPIQUE CBT24 Line Array Speakers

To launch the new EPIQUE line, Dayton Audio collaborated with Academy Award and Audio Engineering Society Gold Medal winner, Don Keele, to create the CBT24 — the first offering from the Don Keele Signature Series. For this new product line, Keele introduced the Constant Beamwidth Transducer [CBT] System, featuring technology based on de-classified military underwater sound research. The CBT24 provides amazingly even coverage in the listening room because of its frequency-independent, extremely uniform three-dimensional sound radiation. The CBT24 system provides extremely even coverage and flat frequency response at all locations in the listening room. These characteristics are rare in speaker systems, especially considering that all you need is a common 2-channel stereo amplifier to immerse yourself in this technology. The CBT24 is available as a finished two way system and as a kit for the DIY/cost conscience buyers.

System description

Each CBT24 contains 24 2-1/2" full-range drivers. These drivers have been designed specifically for this new system. Since these are full-range speakers, there is no need for crossovers that can cause phasing issues. The drivers are mounted on a front panel that has a 36° circular-arc, with the system standing about five ft. tall and a width of only 3-1/2", giving a unique contemporary and artistic appearance. The system provides an extremely well-controlled narrow vertical coverage of 27° that greatly reduces ceiling reflections. The system requires only a single stereo amplifier; an optional DSP Crossover/Processor/EQ and subwoofer(s) can also be added if desired.


The 2-1/2" drivers are Dayton Audio’s ND64-16, which were designed specifically for the CBT24 system. The ND64-16 utilizes a Neo-Balanced 3/4" underhung low distortion motor that is capable of over 6 mm of peak-to-peak excursion and features a copper sleeve to help keep distortion under control. The driver features a rising high frequency response that partially compensates for the inherent roll-off of a CBT array and includes unique design features that widen its high-frequency coverage. These drivers are mounted very close together to take the advantage of mutual coupling - another criterion of the CBT technology.

Designed specifically to eliminate the detrimental effects of floor reflections

The CBT24 is intended to operate over a reflective ground plane and does not suffer from destructive floor-bounce effects. The curved line array of 24 drivers extends all the way down to the floor to take advantage of the ground-plane acoustic reflection. Effectively, the floor provides a reflective surface that acoustically extends the array below floor level and thus creates an array that is over 10 ft. tall and controls vertical coverage and directivity down to below 160 Hz!

The vertical and horizontal coverage of the CBT24 greatly reduces ceiling and wall reflections

Above-the-floor, vertical coverage of the CBT24 is a narrow 28° that is extremely stable with frequency. This greatly reduces ceiling reflections as compared to a typical box-style system. In addition, the horizontal coverage, which is very broad, narrows as you go around the side of the system, which also significantly minimizes side wall reflections.

Extremely even coverage, with no sweet-spot listening axis

The CBT24 has extremely well-behaved and smooth coverage from locations well above the array to points even down at floor level, and at distances from directly in front of the speaker to points in the rear of the listening room. The horizontal coverage is extremely broad and uniform even out to plus or minus 90°. The CBT24’s variation of loudness with distance is also very unique. At standing height, the system’s volume level hardly changes over a range from directly in front of the system to points 10 ft. away!

System Requirements:

Although the system works quite well on its own without EQ from below 100 Hz to 8Khz, the system works best with an active DSP. This may be a separate DSP “only” unit or a receiver that has DSP functions. A DSP unit supplies capability to either extend the low end of the system down to 45 Hz for operation without a subwoofer or to cross the system over to a subwoofer below 80 Hz. The DSP processor also provides touchup EQ to flatten the system’s overall response and to extend the system’s response out to the limits of hearing.

The system can be used on its own with reasonable bass extension down to 45 Hz with EQ, however, the system requires one or two powerful subwoofers below 80 Hz for wide-range operation with high-level deep bass. The system can be played extremely loud and remains very clean and effortless at all levels. The large number of drivers minimizes distortion, and when driven with powerful amplifiers the system can generate very high instantaneous peaks.

About Don Keele

Don Keele has worked for a number of companies in the area of loudspeaker R&D and measurement technology including Electro-Voice, Klipsch, JBL, Crown, and Harman International. He is an AES fellow and holds eight patents with topics including “constant-directivity” loudspeaker horns, loudspeaker arrays, and signal processing. Currently, he heads his own consulting company, DBK Associates and Labs. His passion for the last 16 years has been to promote the use of CBT loudspeaker technology in the loudspeaker industry. Mr. Keele holds two BS degrees (EE and Physics) and an MSEE with minor in acoustics. Since 1972 he has presented and published 50 technical papers, among them the paper for which he won the AES Publication Award, “Low-Frequency Loudspeaker Assessment by Nearfield Sound-Pressure Measurement.” In 2002 he received a Scientific and Engineering Academy Award from the Academy of Motion Picture Arts and Sciences for work he did on cinema constant-directivity loudspeakers.