Its not the voice coil of the speaker that causes the problem, but on 100V line systems it's usually the matching transformer that can go AWOL. And on a large system, all that audio power can heat up the transformer fairly quickly.
Yup
should the fire start in the speaker.
Fire spreading from anywhere below is more likely the reason for installation.
Ceilings are normally a fire barrier protecting the room above, unless someone pokes holes in them for speakers and downlighters.
An intumescent material (one that swells when heated to block up gaps) is part of the blanket, which is also fire retardant.
(Dolby) Atmos speakers are intended to be part of an "object based" surround sound system - so are usually "proper" hifi units rather than your typical tannoy style ceiling mount or 100V line system speaker.
I doubt many use 100v line domestically.
With older low voltage lighting, you could have load of transformers in a ceiling void. And I can see one of those catching fire long before a 100v line type.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.