What? "Fragile ribbons" for high-spl speakers? Yup! A few companies make speakers that use thin film or foil diaphragm high frequency drivers that are high output. Planar ribbon/magnetic from BG Radia, SLS Audio, Wisdom Audio, ADAM Audio are low inductance, high sensitivity, and can be affordable than other thin film drivers.
is one such manufacturer. While they started in the rarefied audiophile market, lately they make more [relative to their original pricing!] more affordable speakers.
They currently offer three product lines: Wisdom Series, Sage Series, and Insight Series, in decreasing price. They
One cool thing about their speakers is that many of the models are line-source. This offers a couple benefits: They don't lose SPL as quickly over distance (e.g. outdoors instead of "6dB double-distance", they're 3dB double-distance), and they have more controlled dispersion vertically (for a vertical line-source) for less ceiling and floor bounce.
So far, I've added two Wisdom Insight models: the Insight L8i and the Insight P6i. The first is a line-source design, and the second is a point-source. The Insight line benefits from trickle-down from the more expensive Sage Series. Their crossover is passive and don't require their own specialized amplifier. The Insight P6i has too-low a sensitivity to really be on the list, as I don't like that it has to be fed peak power to reach 105 dB in-room 12 feet away.
This is the biggest Insight Series speaker. It's priced at $5,000...each. It features a 48" tall high frequency section, next to eight oval-shaped bass drivers. The crossover frequency of 550 Hz keeps most of the vocal range within the PMD drivers. They advertise a sensitivity of 91dB (half-space?), peak power handling of 500w, 4ohm nominal impedance, and max SPL of 118 dB @ 1m, with a frequency range of 80 Hz - 20 kHz (+/- 2dB). Kudos to Wisdom for listing (in the manual) the minimum impedance of 2.5 ohms. In the spreadsheet, I've tried to normalize sensitivity between 8 ohm and 4ohm speakers by dropping sensitivity 3dB. Nominal impedance is supposed to have minimums of 80%, but this speaker's minimum is 63% of nominal, so I should normalize sensitivity at least another 1 dB down. But I'll give it another 3dB for being line-source and thus losing SPL at half the rate of conventional point-source speakers. At half peak-power-handling it would theoretically hit 112 dB from 12 feet, or 108 dB from a 100w receiver.
It's designed to always be used in the vertical orientation, so obviously a center speaker would need to be behind an acoustically-transparent screen.