Bose speaker fix?

[james accordino]

I posted previously that left rear speaker emitted a
horendous squealing sound.  Unplugged it and used
system as normal.  Now right rear makes an electronic
whistle.  Not very loud, but if volume is turned to
minimum, the whistle remains at constant volume.  Is
this the cap. problem people descibed on these
speakers?  Anyone come up with a fix, like installing
a new capacitor?

Thanks
Jim Accordino