Just to clarify something a little here re. "seams"....the speakers cabinets have two different types of seams. Remember that the mdf comes with the vinyl already attached to it, the flat panel is then v-cut almost* through the mdf to the vinyl side per spec, then the whole cut out is 'folded' and glued into a cabinet. So basically you'll end up with a seamless join where the mdf is folded over and then a non seamless join where the next panel joins it. The first two pictures wouldn't concern me, the next two perhaps a little, the last one to me is a bit more of a concern. This is where the mdf was foled over and should be seamless, but it looks like the mdf wasn't quite folded cleanly in that last pick. It's not really a bubble in the vinyl per say although it looks like it. Anyway, I hope you get this resolved...they are excellent sounding surround speakers.
A person convinced against their will is of the same opinion still.