Originally Posted by Dennis Murphy
There's a significant difference in sensitivity--around 2.5 dB, prhaps a smidge less. That would require almost twice the amplifier power to driver the Scan to the same level as the Seas. I'm not sure what you mean by "break up," but the Seas will bottom out sooner than the Scan. The Scan has a linear cone excursion of 9 mm in one directioin. The Seas is only 4 mm in one direction. I can't recommend one over the other for pure fidelity at moderate drive levels. That requires a very carefully controlled test, and I've only been able to construct one such test that I placed any confidence in. When we were developing the SoundScape series, we tried out a number of midranges, and came down to the Accuton and an equally expensive Skaaning midwoofer with a very different cone material (ceramic vs. polypropylene). I optimized crossovers for each midrange that hit the same target slopes and overall frequency response. I shipped Jim my instant A-B volume-compensated switching amps and flew up to Michigan to listen with a bunch of other audio nuts to identical pairs of SS10's except for the midrange. It really didn't take us very long to decided that the Accuton was cleaner and more transparent than the Skaaning. Without a parallel test for the Illuminator vs. the Seas Excel, I really wouldn't venture a guess.
Would the bottoming out problem be mitigated by crossing to a subwoofer? Since we're talking about bookshelves I assume the speakers would be crossed, so that begs the question: does the increased power handling still come into play before extremely loud levels, say 100dB and less (what's your definition of moderate levels??)? If not, would the Seas be a better choice then?
I had the pleasure of hearing the Illuminator speaker at RMAF 2012 run full range, and it didn't stuggle in the least bit IMO, and I was honestly surprised by how punchy the speaker was, not to mention how deep it went. Not bad at all!!!