If they have a front grill perpendicular to the bottom, place them in a basement, spare room, garage or another dry out of the way place face-to-face, hook them up out of phase to an amp & tuner or CDP, throw a thick blanket over them and turn up the volume. The theory is: being out of phase the speakers will cancel each other out.
The thick blanket will help with stray high-frequencies. In practice, however, you'll have to deal with stray low-frequencies.
The speakers won't be absolutely silent but is much better than the alternative.
Good luck.
The thick blanket will help with stray high-frequencies. In practice, however, you'll have to deal with stray low-frequencies.
The speakers won't be absolutely silent but is much better than the alternative.
Good luck.