Those are really huge speakers!!! Heard that the home owners love to karaoke at home...so there's a set of bifold doors between balcony and living and on top of that to seal in the sounds, there's also another set of windows at the balcony!
above: bifold windows installed for kitchen bar counter top. But installed wrongly. sigh. Sometimes the workers can be quite blur. The bifold windows are meant to fold to one side and not both sides.