hi, this is my first post here. i leave birdseed and water out on my rooftop for the feral pigeons, and recently have decided that id like to build some dovecotes for them to nest. i happen to have a good size collection of shot stereo speakers/cabinets (long story), and i realized that these might make perfect little homes, if a pull out a speaker, thus creating an entrance hole. many of the tweeters are mounted to four inch holes, which strikes me as sufficient for the pigeons to enter and exit (is this correct?), but gutting the woofers would leave anywhere from an 8 to 12 inch hole that id then have to patch with something else. i should admit that i sorta like the aesthetic of leaving the large speakers in place anyway, but this is where my main question comes in: i have been reading up on pigeons and learned that they have minute traces of magnetite, which they use to orient themselves via the earths magnetic fields. for those who dont know, speakers are basically big-ass magnets. does anyone know whether this would be bad for the birds? its obviously the least of my intentions to bring any harm to my little flying friends. didnt kow if sleeping next to a magnet would completely disrupt their sence of orientation, or even make their little heads pop off. any elucidation would be much appreciated. thanks.