I think I've asked this question a few times in my career but would like to see if there is an update:

What is a good surface mount or in-ceiling speaker to use in a sauna? Plastic is said to create off-gassing that can be toxic. Is there a speaker that does not contain plastic and can withstand heat even if located near the ceiling?

Hi Mr Tristan-

You are correct-the off gassing thing is a whole other complication to this issue! We did have an experience using a Totem Acoustics flush ceiling speaker in a sauna ceiling that worked for several years, but eventually warped/melted. Right now we are tasked with sourcing a more rugged replacement. When you search for sauna speakers you do get results of quite a few surface/flush models designed to "take the heat" All of them I found also looked like they were not very hifi that I found. We kept digging and came upon the Revel XC Series of speakers-the Extreme Climate models. They are outdoor rated and designed to take the heat of outdoor Summer install in desert homes. Our Revel rep told me that XC speakers would withstand Sauna install. Not sure if this link will post? [Link: revelspeakers.com] good Luck!

i dont know i have some outdoor speakers in mine... not in it enough to worry about outgassing

I want to see a peer reviewed, scientific report done on this off-gassing of outdoor rated speakers in hot environments.
I'm sure if measured, everything in a Sauna gives off a little bit of something when heated. Doesn't mean it's enough to cause issues or anything that is dangerous.
Until I see a study or report I trust, I call BS on this!

As far as speakers that can take high heat and last in a hot environment - Sonance has the "Visual Experience Extreme" speakers that are rated for tough environments. Including temps up to 194°F. The spec sheet has a list of ASTM standards it passes.

What is the highest temperature in the sauna? Can't be much more than 105°F, right?

Metal boxed outdoor speakers- even plastic work well in hot climates but no idea if <120° temperatures cause outgassing issues.

Metal grills and rims will outgas less, however, steel will tend to rust.

Thanks everyone, I'm not going to worry about it now as long as I use a sauna rated product:

[Link: share.google]

Steam! The rising steam that hits the ceiling (heat rises) can get to 195°F in a Sauna.

If you were using certain non-outdoor rated (or cheap outdoor rated) speakers, this could cause them to melt or otherwise damage them over time.
Mentioned above, apparently Totem (although they make great speakers, they don't make outdoor rated or extreme rated) don't do well in excessive heat over the long term.

Not if it has been powder coated- that needs about 350°F-400°F degrees in order to melt.

And how do humans survive this temperature? Whatever the temperature is in the sauna space, the highest temperature will be at the point where the steam is produced but it cools significantly as soon as it mixes with the air and contacts the surfaces.

You should probably go read some installation guides from a couple of sauna companies. That's what I did before I posted so I wouldn't make assumptions and could post some facts. And not end up posting something that might be wrong and cause misinformation.

According to the manuals & guides = People usually experience temps of 120-140°F on the bench (steam saunas 110-120°). Temps at the "CEILING" are where the hottest temps are experienced in a sauna. And can get as high as 195°F in Finish style dry saunas.

A note for the OP = It seems putting speakers under (or built-in) the bench seating is a popular place. Makes sense to me considering the environment.

We usually install surface mount outdoor speakers under the bench’s. Have a few homes with the dpeakers still working and looking good after 10-15 years.

Outdoor speakers under the bench is good .. usually get a nice bass bump.
Have done several electric saunas with the Revel C363XC also.
Never gotten to test them out under operating conditions though.

Sonance Extreme, as someone mentioned.

Someone else mentioned "lasted for several years then started to warp" - shoot, in a harsh environment, several years sounds like acceptable service to me.

Maybe try some transducers mounted to the outside of one of the walls or windows? :)