A.You can mount a pair of PM-3 monitor speakers using the mounting bases that come with the PM-3 (Fig. 1.)

Use the following procedure.

For your reference:
For an alternative method of attaching the PM-3 monitor speakers using the mounting brackets, refer to the following FAQ:
Can I mount a pair of PM-3 monitor speakers on the MDS-20BK?
(2005/04/08)