Speakers in a line array are always limited by their center-to-center mounting distance, driver-to-driver, when it comes to high frequency reproduction. When the wavelength being reproduced by the speakers is physically smaller than the center-to-center distance, the speakers begin to experience destructive interference (which is commonly referred to as comb filtering).
For instance, multiple drivers used in a line array that have a 2" minimum center-to-center distance will begin to experience comb filtering at and above roughly 6,750 Hz. This creates havok on subtle imaging cues, high frequency playback, and top-end sparkle.
This 1/2" inverted dome tweeter element is sold in packs of 10 and are the perfect high frequency element for use in high fidelity line arrays. A 7/8" minimum center-to-center distance allows for unaltered frequency response all the up to and above 15,000 Hz! A low 450 Hz free-air resonance frequency allows you to crossover to a fairly large driver while maintaining seamless integration. The frame design requires mounting the tweeter from the rear of the baffle using a 3/4" opening and securing it in place with epoxy.
Note: Higher power handling and output can be achieved by using multiple tweeters together, and using a 2nd-order 1,500 Hz filter. For example, a series-parallel group of four tweeters will handle 8 watts RMS/16 watts max while increasing the SPL to 72 dB. Two series-parallel group of four tweeters paralleled together (for a 4Ω load) will yield 16 watts RMS/32 watts max (without a filter) and increase output to 78 dB.