Технический обзор Bose 802 series III зачем там PTC

Full range
A full-range loudspeaker drive unit is defined as a driver which reproduces as much of the audible frequency range as possible, within the limitations imposed by the physical constraints of a specific design. The frequency range of these drivers is maximized through the use of a whizzer cone and other means.

A capacitor will act as a HPF, blocking the low frequencies, thus protecting the tweeter. Perhaps I don't understand your question, but a PTC will do nothing to protect the speaker in the event of a crossover malfunction, which is the entire point of using a capacitor.
PTC will work as sensor temperature
unless it is thermally coupled to the voice coil

Specifications

Bose flagship loudspeaker
Indoor or outdoor use
Speaker ideal for vocals and instruments
240W RMS/480W peak power handling
Panaray 802 III Loudspeaker
Frequency range: 55Hz to 16kHz ±3dB
Sensitivity: 91dB-SPL @ 1W, 1m (pink noise)
Maximum Acoustic Output: 114dB-SPL @ 1m(pink noise), 116dB-SPL @ 1m (IEC3 noise)
Dispersion (-6dB point, average, 1-4kHz) Horizontal 120, Vertical 100
Long-Term Power Handling: 240W continuous
Impedance: 8 Ohms nominal
Dimensions (HxWxD): 13in x 20.5in x 12.5in(33cm x 52cm x 32cm)
Weight: 31lb. (14kg)

group of bose 01 are
Bose 101 Bose 202 Bose 301 Bose 401 Bose 501 Bose 601 here Bose 701 Bose 801 Bose 901 final

parallel JBL