In Ceiling Speakers - hot climate - Moisture Concerns ?

As long as the attic is ventilated per local codes there should be no problem. You might want to consider a speaker that is rated for outdoor use as well since they are (supposedly) better at resisting moisture.

My personal suggestion would be to enclose the space for which the in-ceiling speakers are installed. This is realitively easy to do if they are exposed to an attic space. Simply use at least 5/8 drywall and build a box over the ceiling mounted speakers, tape and mud all joints. This will make your speakers considered to be part of the conditioned envelope, and solve your moisture related issues or concerns. Same thing applies to ceiling mounted speakers on first floor between second floor joists'. Of course both scenarios will require drywall patching, texture blending and paint. Complete casing is never as quick and easy as just cutting the speaker enclosure into the ceiling. This is just the quick gist of it.... As like all posts on here this is open to criticism from all angles as I am sure somebody will be quick to shoot me down. There is nothing technical in the basic fact of encasing in-ceiling mounted speakers to make them part of the conditioned space.

Oh and btw.... Your speakers will not have moisture accumulation on the cones from the conditioned space versus the attic. The temperature differential between in room versus attic space is not enough to create a moisture accumulation problem. If there was ever a concern about this happening the existing ceiling drywall would be soaking wet with moisture. In which I'm sure you or anybody else has never experienced. The speaker is no different than the drywall itself in regards to initial question.

My above response was directed to bring your in-ceiling mounted speaker into the conditioned space without being physically mounted in the room. Hopefully all that makes sense.

All in all at the end of the day what I mean is it's not necessary to enclose the area around the in wall speakers. However..... There is no harm in casing around those in wall speakers if you feel necessary in doing so.

-Cheers

Since you asked...

I'd strongly suggest he stay away from in ceiling and if he must, go in wall where he can bring the fronts (at minimum) down closer to ear level AND more importantly, make it seem the tv/screen is the source.

My neighbor in Tennesse has a 12K sq/ft house. Main room has (I think) about 15' ceilings and they have ceiling speakers.

One day his wife scurries me in there saying "come & listen to our surround system"

Major let down.

Happened the news was playing. Voices were coming from above. It was basically like God was talking down to us telling us that it was going to be rain the next day.

Epic fail in my opinion.

Lol.... I would definitely have to agree with you there. I didn't mention that point cause it sounded like they were dead set on the in ceiling speakers. But definitely a point worth mentioning.