NAD is nice, but even they have their limits. Likkewise, i'm somewhat familiar with maggies and their way of handling bass. I'm also familiar with what a stressed amp on the verge of cbeing overdriven sounds like with maggies. They sound glaring, tinny, harsh and strained.
When I was running my MMG's, my NAD 214 (80wpc@ 8 ohm) power amp was "adequate" but I was using a powered sub, cutting in around 60 hz, which is just about where they cut off.
When I upgraded to the 1.6's, my trusty 214 was woefully inadequate. I needed to upgrade to a Rotel RB-991 (200 wpc @ 8 ohms). I still use a sub but run 'em full range and have the sub start cutting in around 45 - 50 hz or so.
Remember, when an amp reproduces bass, it puts a tremendous strain on the system across the entire frequrency range. By ading more power you won't necessiarially be making it "louder", but you will be able to provide the juice needed to handle the bass peaks and, hopefully, still have enough clean power so the rest of the range won't be degraded, which, IMNSHO, seems to be the current situation.
That receiver would be a better match for more efficient speakers.
I'm of the opinion that your receiver, while excellent in many other respects, simply lacks the juice to do those speakers justice, particularly when trying to do serious bass. Acoustic, folk, chamber, light symphonic (and that's questionable), opera, vocals, and such may be fine at low to moderate volume but you're running out of steam should you try to do a stand-up bass at realistic levels. Don't even think about loud electric bass, deep synth, or organs at satisfying levels.
As a point of interest, remember that doubling the available power will afford you about three db increase in headroom which, in the grand scheme of things, ain't much. And, never, ever confuse momentary "dynamic power" with real "RMS" or "continious" power.
