James Harris wrote:

My speakers have four spikes beneath them which makes it a pain to
move the speakers even slightly as the length of at least one spike
has to be adjusted to make all four rest on/in the floor. (The floor
is solid - maybe concrete - and not wood.)

Why do you want to move them around so much? Take the spikes off, experiment
with positioning the speakers for a week or two. When you're satisfied they're
optimally placed, put the spikes back on and leave them on and be done with it.