Assuming the TS is thinking of using identical loudspeakers.

And enclosures. I was thinking of speakers built in to the wall, but that might not be the case.

 

And enclosures. I was thinking of speakers built in to the wall, but that might not be the case.

Agreed. I was using the term “loudspeaker” to represent the complete item: driver + crossover+ enclosure.

 

I have never connected speakers in series.