18 Sound XR2064C – Constant-Directivity 2-Inch Horn Flare with Focused 60° × 40° Coverage for Large-Format Systems
The 18 Sound XR2064C is the largest-throat constant-directivity horn in 18Sound’s XR series. With a 2-inch (50 mm) throat entry, 60° × 40° constant-directivity coverage maintained from 1.2 kHz to 16 kHz, and a 0.8 kHz cutoff frequency, the 18 Sound XR2064C delivers the same four-octave constant-directivity performance as the smaller XR1496C and XR1464C — but scaled for the 2-inch exit compression drivers that produce the highest output and best low-frequency coupling of any standard compression driver format.
The 2-inch throat is the largest in 18Sound’s XR horn range. A bigger throat means more acoustic energy couples from the compression driver to the horn at lower frequencies, which is why the 2-inch format produces cleaner, more powerful output in the 800–2000 Hz mid-range band than 1-inch or 1.4-inch exits can achieve. For large-format touring systems, arena installations, and high-output three-way designs where the compression driver handles the mid-high section, the 2-inch exit on the 18 Sound XR2064C is the format that delivers the most authority.
The 60° × 40° coverage pattern is the focused, long-throw variant in the XR series — the same coverage angles as the 1.4-inch XR1464C but from a 2-inch throat. The narrower horizontal coverage concentrates energy toward the back of the venue, maintaining SPL at distance. The tight 40° vertical keeps energy focused on the audience plane, reducing ceiling and floor reflections that degrade intelligibility.
18Sound designed all XR series horns to eliminate the midrange narrowing and high-frequency beaming problems common in many similar horns on the market. The 18 Sound XR2064C maintains smooth frequency response from 1.2 kHz to 16 kHz on-axis and off-axis in both horizontal and vertical planes — the defining characteristic of a constant-directivity horn done right.
At 1.6 kg in high-damping composite construction with a 270 × 270 mm face matching the XR1496C and XR1464C footprint, the 18 Sound XR2064C shares the same baffle cutout and face dimensions as its smaller-throat siblings.
Design and Construction of the 18 Sound XR2064C
The 18 Sound XR2064C uses a constant-directivity flare profile with a 50 mm (2-inch) throat entry expanding to a 270 × 270 mm mouth. The 50 mm throat is 15 mm larger than the XR1464C’s 35 mm and double the XR1496C’s 25 mm — providing significantly more cross-sectional area at the entry for acoustic energy transfer from the compression driver.
The larger throat directly benefits low-frequency performance. At 800 Hz, a 50 mm throat couples more acoustic energy to the horn than a 35 mm or 25 mm throat can manage — the larger opening handles longer wavelengths more efficiently. This is why 2-inch compression drivers paired with 2-inch horns produce more powerful, cleaner output in the 800–2000 Hz band than smaller-exit systems. The compression ratio is lower, the distortion is lower, and the output at the bottom of the operating range is more authoritative.
The constant-directivity flare counteracts the natural coverage narrowing that all finite-sized horns exhibit as frequency increases. The 18 Sound XR2064C’s flare geometry maintains 60° horizontal and 40° vertical from 1.2 kHz through 16 kHz — nearly four octaves of consistent pattern control. Below 1.2 kHz, the coverage begins to widen as the horn loses directivity. Above 16 kHz, it begins to narrow as the wavelengths become too short for the mouth dimensions to control.
Within the 1.2–16 kHz constant-directivity window, the off-axis frequency response tracks the on-axis response closely. A listener at the edge of the 60° horizontal coverage hears tonal balance similar to a listener on-axis. This consistency across the coverage area is what makes constant-directivity horns essential in professional system design — the system sounds uniform across the audience, not just at the centre.
The high-damping composite material structure matches the XR1496C and XR1464C. Composite provides the stiffness needed to resist deformation under acoustic pressure without the resonant ringing that metal horns produce. The high-damping properties absorb vibrational energy that would otherwise colour the output. And the composite construction keeps weight optimised — 1.6 kg for a 270 × 270 × 200 mm horn with a 50 mm throat is competitive.
The 200 mm depth is 20 mm deeper than the XR1496C and XR1464C’s 180 mm. The additional depth accommodates the larger throat and the longer flare path needed to transition from 50 mm to the 270 × 270 mm mouth. For cabinet design, the extra 20 mm of depth behind the baffle needs to be accounted for — but the face dimensions and baffle cutout remain identical to the smaller XR horns.
The 270 × 270 mm face and 240 × 240 mm baffle cutout match the 1.4-inch XR horns exactly. A cabinet originally designed for the XR1496C or XR1464C can accept the 18 Sound XR2064C from the front with the same baffle opening — only the depth behind the baffle differs. This dimensional compatibility gives system designers the option to upgrade from a 1.4-inch to a 2-inch HF section without redesigning the cabinet baffle.
The very low distortion at high sound pressure that 18Sound highlights is a consequence of both the composite material’s damping and the constant-directivity flare’s smooth internal geometry. The flare transitions progressively from throat to mouth without abrupt changes in cross-section that would generate internal reflections and distortion products.
Performance and Applications for the 18 Sound XR2064C
The 18 Sound XR2064C provides 60° × 40° constant-directivity coverage from 1.2 kHz through 16 kHz when loaded with a suitable 18Sound 2-inch exit compression driver. The 0.8 kHz cutoff ensures the horn provides useful acoustic loading and pattern control from 800 Hz — well below the typical 1–1.5 kHz crossover frequencies of 2-inch compression drivers.
The 60° horizontal coverage is the standard angle for medium to long-throw applications. In large venues, the 60° pattern concentrates energy toward the audience at distance rather than spreading it across side walls. For venues wider than 60°, multiple cabinets can be arrayed horizontally with overlapping patterns — the standard approach in professional large-venue PA design.
The 40° vertical focuses energy on the audience plane with maximum precision. In flown systems angled downward, the 40° window can be aimed from the front row to a specific distance, with minimal energy spilling past the intended coverage boundary. The tight vertical control improves the direct-to-reflected ratio in the listening area, directly benefiting vocal intelligibility and musical clarity.
The 2-inch throat advantage over the 1.4-inch XR1464C (which shares the same 60° × 40° coverage) is in the mid-range output quality. The 18 Sound XR2064C produces lower distortion and more output in the 800–2000 Hz band because the larger throat reduces the compression ratio and handles mid-frequency content more gracefully. A 2-inch compression driver producing the same SPL generates less back-pressure at a 50 mm throat than it would at a 35 mm throat — the physics are straightforward.
For three-way systems where the compression driver handles the entire mid-high section from 1 kHz upward, the 18 Sound XR2064C’s 2-inch throat provides the acoustic coupling that makes the crossover transition from woofer to horn smooth and authoritative. The horn loads the driver efficiently from its 800 Hz cutoff, and the constant directivity from 1.2 kHz means the horn controls coverage across almost the entire compression driver operating range.
The dimensional compatibility with the XR1496C and XR1464C (same face, same baffle cutout) means system designers can offer multiple horn options from the same cabinet platform. A two-way top originally designed with a 1.4-inch horn can be upgraded to a 2-inch horn by swapping the horn and compression driver — as long as the 20 mm of additional depth behind the baffle is available. This upgrade path from 1.4-inch to 2-inch lets builders step up the HF section’s output and mid-range authority without redesigning the cabinet.
The 18 Sound XR2064C pairs with 18Sound’s 2-inch exit compression drivers. For Surgesound customers considering B&C 2-inch drivers like the DE1095TN, horn compatibility should be verified at the bolt pattern and throat geometry — the XR2064C is optimised for 18Sound transducers, but the 50 mm standard throat accepts any driver with a matching 2-inch exit.
Conclusion – 18 Sound XR2064C Horn Flare
The 18 Sound XR2064C is the largest-throat constant-directivity horn in 18Sound’s XR series. The 50 mm throat couples more acoustic energy from the compression driver at mid-range frequencies than any smaller-exit horn in the range, producing more authoritative, cleaner output in the 800–2000 Hz band where most of the musical and vocal energy lives.
The 60° × 40° constant-directivity coverage from 1.2 kHz to 16 kHz provides nearly four octaves of consistent pattern control — the same proven XR-series performance scaled for the 2-inch compression driver format. The high-damping composite construction eliminates horn-induced resonance while keeping weight to 1.6 kg.
The shared 270 × 270 mm face and 240 × 240 mm baffle cutout with the XR1496C and XR1464C mean the 18 Sound XR2064C drops into existing XR-series cabinet designs with only the 20 mm additional depth to manage. For builders upgrading from 1.4-inch to 2-inch HF sections, the cabinet compatibility simplifies the transition.
For large-format touring systems, arena installations, long-throw PA, and any application where a 2-inch constant-directivity horn needs to deliver focused 60° × 40° coverage with the cleanest mid-range output and widest constant-directivity bandwidth available in a composite horn, the 18 Sound XR2064C is the 2-inch XR that carries the series’ engineering to its largest format. Biggest throat, most mid-range authority, same proven constant-directivity design.
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About 18 Sound
18 Sound products are proudly made in Reggio Emilia, Italy, combining advanced technology with Italian craftsmanship. Known for their high-performance professional audio components, 18 Sound is a trusted name in the global audio industry. Their state-of-the-art manufacturing and strict quality control ensure exceptional reliability and sound clarity. 18 Sound products are designed to meet the demands of speaker builders and audio professionals, 18 Sound offers premium products with outstanding value and performance worldwide.
