Faced with choosing loudspeakers, numerous factors determine the best topology, which typically comes down to: point source speakers or line arrays? Each has pros and cons based on where they’ll be used, among other factors. Generally, point source speakers work better in wide, shallow spaces, are aesthetically tidier and can grant control over dispersion in the horizontal axes. Line arrays work better in narrow, deep spaces, provide better control over dispersion in the vertical axis, and can offer a ton of SPL. So it’s an easy matter of choosing speakers based on the space they’ll be used in, right? What if they’re going to be mobile, intended for use in a variety of spaces? It would be nice to have some kind of a hybrid that offers benefits from both topologies. PreSonus has introduced its CDL (constant directivity loudspeaker) series, and these do indeed exhibit positive characteristics of both types.
PreSonus CDL Principles
The principles of the CDL speakers were initially unveiled at AES New York, in October 2017. A white paper published by Hugh Sarvis and D.B. Keele, Jr. and describes a system in which a vertical line of eight 2-inch HF drivers is arrayed in a 20° circular arc projecting outward in front of a 12-inch woofer, essentially effecting a coaxial loudspeaker with certain benefits that accrue to line arrays. The speaker enclosures are wedge-shaped with the top and bottom panels splaying 20° from each other toward the front, to match the 20° circular arc of the HF array. Multiple enclosures can be physically coupled to achieve a longer arc, increasing vertical beamwidths and improved directivity. A single box behaves much like a point-source loudspeaker, but the addition of more boxes creates larger vertical coverage and acts like a larger constant directivity horn while still radiating from the center of the array.
Enclosures and Hardware
PreSonus offers the full-range CDL12 ($1,999/street) and CDL18 subwoofer($1,999/street). The published ±3 dB frequency range of the CDL12 is 48 Hz – 18k Hz (a true figure, based on my ears). The enclosures are 15mm Eucalyptus plywood, with the CDL12 measuring 18.6×20.8×17.5 inches (HxWxD) and the CDL18 is 22.2×20.8×24 inches. The comfortable recessed carry handles for both speakers are cleverly integrated into the speakers’ rigging hardware. The speakers can be flown in a multitude of configurations, ranging from a single CDL12 up to two CDL18s with five CDL12s. The system can be pole-mounted, ranging from a single CDL12 to a pair of CDL12s atop a single CDL18, up to a single CDL12 atop a pair of CDL18s. The CDL12s’ two pole receiving are oriented as 0° or 10° downward. The enclosures can also be stacked in any configuration up to two CDL12s atop two CDL18s.
The front of the CDL12 enclosure features two metal panels on either side of the line of HF drivers, extending toward the vertical edges of the face, but leaving an opening that facilitates the egress of SPL from the LF driver, not only directly, but also via the cabinet’s four ports. Normally, there would be concern over the delivery of the LF driver’s highest frequencies, which can reach nearly 2k Hz in some systems, and hence be quite directional. But in the case of the CDL12, the crossover point is 420 Hz, so the LF driver’s output is not particularly directional to begin with, and is sufficiently delivered via the vertical openings in the front panel. These speakers look and feel very solid. They’re not exactly lightweight, but hardly back-breakers when properly handled by two persons. The CDL12 is 65 pounds; the CDL18 is 105 pounds.
The Drivers and the Rear Panel
Rear panel connections on both types of speaker include XLR line inputs and direct (loop-through) outputs, a Dante/control port and preset selection pushbuttons. The CDL12 has a button to engage its 90 Hz HPF, and the CDL18 has a button to toggle the speaker’s polarity. Both speakers also feature six status LEDs to indicate operating temperature, signal levels, protection limiter and network connection. Both speakers sport powerCON AC inlets and loop-through outlets and a mains switch. On both speakers, a large swath of the rear panel is occupied by cooling fins.
The CDL12’s LF driver features a 2.5-inch voice coil, and the eight HF drivers have 1-inch voice coils. Internal amplifiers are Class-D, delivering an equal 500W program (250W RMS) each to HF and LF, for a total of 2,000W peak/1,000W program (500W RMS). The published max peak SPL is 131dB. The CDL18’s driver has a 4-inch voice coil, and it is driven by a 1,000W program/500W RMS Class-D amp. Its published frequency range is 42 Hz — 150 Hz, which is variable based on crossover cutoff frequency.
Worx For Me
Audio can be fed via Dante and the speakers can be controlled remotely as well when connected via LAN through the speakers’ RJ-45 Ethernet ports. PreSonus’ Worx Control app can manipulate a number of speaker functions and provides real-time status information about each speaker to the user, including level metering and operating temperature. Among the remotely controllable app functions are muting, filtering, preset selection, level, alignment delay, limiting, compression and choice of physical input. The speaker’s analog or Dante input can be selected, and there’s also a welcome “analog failover” mode in which Dante is the default input, but if a loss of network sync occurs, the speaker automatically shifts to the analog input. Eight filter types are available for each of the speaker’s fully parametric EQ bands: bell, notch, all-pass, low shelf, high shelf, band pass, high pass, and low pass. Butterworth and Bessel topologies are available at 6, 12, 18, and 24 dB/octave slopes, and Linkwitz-Riley is available at 12 and 24 dB/octave.
The Test Drive
PreSonus have developed a reputation for very solid products that deliver the goods, and the CDL series more than meets it. I am impressed with these speakers. They are straightforward to set up and operate, offer contemporary functionality and they sound very good. I listened to a wide variety of sources, including speech and music spanning multiple genres (and some of my own studio mixes with which I am intimately familiar). The high quality drivers deliver clear audio within a predictable dispersion pattern to the audience, while avoiding projecting SPLs to the walls and ceiling. With the crossover at 420 Hz, the combined eight 2-inch HF drivers handle a lot more of the range, allowing the woofer to focus on woofing — and it makes a positive difference. I also found its traditional cone HF drivers were less fatiguing to my ear, and less susceptible to the brashness that can afflict metal compression drivers. The low-end is punchy and full, and the CDL18 subwoofers are truly only necessary for applications that traditionally require substantial bass — DJs, EDM, clubs and the like. The delivery of energy over the frequency spectrum sounded smooth, and the controlled dispersion pattern facilitates a clear, well-defined stereo image.
Conclusion
Even when flown six boxes high, the PreSonus CDL12 is not a true line array. Yet it’s not a pure point-source speaker. It delivers some of the advantages of both. When multiple boxes are deployed into a vertical array, the energy is no longer dispersed equally from each box, it is based on the entire array. Again, not a true line array, but a hybrid that delivers great results. Delivering quite a bit of bang for the buck, these speakers are definitely worth considering for either portable or installation projects.
At a Glance
One Box, Two Topologies
PreSonus’ CDL (constant directivity loudspeaker) series are designed to serve as a hybrid that combines the advantages of a line array with the simplicity of point source designs. Our reviewer found that the CDL12 and CDL18 subwoofer exhibit positive characteristics of both types of speakers.
PreSonus CDL12 and CDL18
PROS
- Dante and analog inputs
- Versatile control software
- Excellent construction quality
- Smooth mid and top-end response
CONS
- Not simple enough for casual musician use
- Somewhat heavy for single-person setups
STATS
Configuration: Constant directivity configuration
Power: 500W RMS (CDL12); 500 W RMS (CDL18)
Frequency Response, CDL12: 48 Hz to 18k Hz (±3 dB)
Max SPL, CDL12: 131 dB peak (@ 1m)
Size: CDL12: 18.6×20.8×17.5”; CDL18: 22.2×20.8×24”; (HxWxD)
Weight: CDL12: 65 lbs.; CDL18: 105 lbs.
Street Price: $1,999 for CDL12 or CDL18
Manufacturer: PreSonus
More Info: www.presonus.com
