the MA silver 6 and 8 each have a rear port, which can be plugged or not w/the supplied plugs. does this port location place a tight constraint on speaker placement, ie do you need to put it a certain minimum distance from the wall to get optimum sound? this could factor significantly into the purchase decision.
Monitor includes the plugs for situations where the speaker will be near a wall. I have the Silver 2 and my right speaker is very near an outer wall so I put the plugs in both fronts and it did help so if that is your situation don't worry about it. Take them home and try them out after understanding your stores return policy. You should insist on at least a week for full return, money back etc. Also the MA's need at least 60 hours or so of break in if new ao be aware of that. After break in they will warm up considerably, especially the silver center which is IMO the real gem of the silver line.
Anytime you place a speaker closer to a wall (or boundary) the lower frequency output you hear increases. Your ear would perceive this as increased bass, as the boundary dependent region is reinforced (low frequencies) as the bass bounces off the intersecting surfaces. Rear ported speakers, MA's, Paradigm Studio & Performance, Monitor etc that have rear firing ports have flexible placement, but putting them close to walls can over-do the bass. These round foam inserts MA provides can block or reduce the effect if you choose near wall placement because of room set-up, furniture etc. You can always experiment with tilting the plugs sideways. I used to put a sock in my KEF"s coupled-cavity right speaker because I had it near a wall & couch. Guests used to sqauk about it, so I occasionally removed it. The realelitefan is correct in stating a long break in time for MA's on account of their STIFF proprietary driver material. So actually, the 'tuning' benefits of a rear port(s) and placement options would add to the flexibility of that speaker. A little time spent positioning/toeing the speakers and adjusting the foam inserts and twiddling with your tone controls (unless defeated) should give excellent results. Nothing says each speaker has to have the foam in the same relative position.
elitefan - if i correctly assume that your silver 2's are your mains, what are you using for surrounds? i'm considering the 6's or 8's for mains, and am not sure whether to go for direct firing 1 or 2, or dipolar sfx or sfxi, for surrounds. in my room the couch is against the back wall, and the surrounds will need to go on the wall over my head, or on stands on either side of the couch. which MA surrounds did you consider and how did you choose?
bigfan, I am using the Silver s1 as my surrounds because I wanted a direct radiator for my surrounds as they are better for dvd concert movies which I watch alot of. The s1 works great for regular movies also so I can recommend them for any surround application.