audio speaker housing in cemen

huangyhg

audio speaker housing in cement
good day engineer gurus!
i am in need of your concrete/structural expertise please.
i need for some audio speakers(6 1/4 diameter) to be encased into an 11" floor of cement, in between an 8x8 square of rebar somewhere in each floor.  need to be able to screw into housing in anyway to hold the speaker in place.  these will be throughout each floor/ceiling going into condos.  
i need the housing for each speaker to be able to handle the pour of cement and possibly stay in place.  cost is a major issue(over budget) if we use metal don't want any rust issue, only using a clear sealant on exterior of concrete.   
i am looking at sono tubes, but they are cardboard?
once i come up with a solution, i need to present to a group of architects.  if you have any questions, feel free to write me.  
thank you in advance for all your assistance!
are the face of the speakers flush with the floor?
does the speaker sit just partially into the floor (i.e. do you need the entire 11" of depth for the speaker?)?
how will the speaker be wired?
is this new construction?
you mention rebar at 8" on center in each direction, what size is the bar?
some kind of custom sheet metal form to get a round hole or pvc pipe.
i am not sure how small of a sonotube form there is, but i am sure that they don't come in fractions.
are you asking whether this is possible or asking for design advice?  if the latter, contact a local engineer or the actual design engineer for the floor.
if i'm not mistaken, i think the speaker people normally want a fairly large open area behind a speaker.  ie, if these are for music use, check on the speaker requirements to see if you need a bigger hole than what the speaker occupies.  if it's just an intercom or doorbell or something, that shouldn't be an issue.
i've never done anything like this.  but take a look at
jimbo beat me to the punch.
it's concrete, not cement.
a properly designed speaker system includes the enclosure, driver and electronics.  combined they yield a characteristic sound quality.  throwing any old speaker into any old hole with any old circuitry will only randomly yield good sound (assuming good sound is your desire).  i would suggest finding a speaker / loudspeaker that is integrated with it's enclosure and fits into your restricted space.  there are many good companies out there that make indoor and outdoor sealed-box speaker systems that you could mount into a void in your concrete.