I have not heard the Silver Iris but I have now changed the woofers in my Lowther OB system to the Eminence Alpha A15 which has a Qts of about 1.2, I updated my site to reflect this yesterday. I think these Eminence drivers are very close (if not the same) to the Silver Iris 15 inch driver. The bass is as you describe, deeper and warmer compared to the lower Qts Dayton drivers I was using before and could easily support a smaller baffle. With my big baffle the bass goes very low for an OB system.

The one difference in the Silver Iris and my system is the location of the crossover point. I am rolling the Eminence drivers out at 200 Hz using a 12 dB/octave filter. Obviously the Silver Iris uses the woofer to a much higher frequency which may or may not be a concern. I will have to play with my active crossover to see how things work crossing over higher. Would you happen to know at what frequency the Silver Iris corsses to the coaxial horn tweeter? But based on my experience with the Eminence Alpha driver, I bet the Silver Iris sounds very good in a "smaller" OB at a great price point.

Martin