Thanks Mizuno. I tried the port plugs but my speakers are quite a distance from the wall so it actually made them sound worse, not better. It does tighten up the bass, but I find it affects the midrange a bit negatively as well. Not a huge difference, and hard to put in words, it just sounded like a smaller speaker.
As for the bass concerns, I don't want to give the impression the bass is horrible. It's a bit muddied, a bit boomy, yes. But it's a lot better than other speakers I've heard in floor standing models. The Totem Hawk uses a much more expensive driver, and the Veritas is a completely different technology. Both are in smaller cabinets as well.
Sorry, I've never heard teh Spender 5se.
I really enjoy the depth of the sound field the RC-70's display. I also like the fact you can listen for hours with zero fatique. The bass 'issue' and slightly 'recessed' highs do detract, but it's not a $5000 speaker so it won't be perfect. No speaker will be in that price range.
I do like them, but so many speakers, so little time