The Dynaudio MW180 vs the Dayton RS225 for comparison.

AJ was nice enough to send me one for evaluation purposes.

Frequency response at 1".

Linear distortion

Nonlinear distortion

Spectral distortion

Just for additional reference (and you'll see why later) I pulled out an SS8555 for retesting.

Single tone HD testing-

I threw in the SS8555 because I was puzzled by the showing of the RS225 in this test. If you compare this to my original test of the prototype RS225, it fared notably worse. Again, more on that later.

Three tone, SL style-

Conclusion

The Dynaudio MW180  has a remarkably smooth FR curve and associated outstanding linear distortion. On the flip side, it does not distinguish itself in regards to nonlinear distortion. It is clearly not as good as the SS8555 or the original RS225 prototype. If I were to guess, there is a foam/metal pole vent grill which causes some higher order distortion. Though this would be better in a box, still, much of the sound radiates out the front of the cone.(Look at spectral distortion test, which is done at 1 inch.)

The behavior of the RS225's is a bit puzzling. It clearly does well, as the prototype did, on the spectral and nonlinear distortion above 100 Hz, but it did notably worse on the 60 Hz  single tone test. I checked another one I had and this was similar. I will likely test the other two (I bought four RS225's) at some point and update. Also, I'll make Darren aware and recheck one sometime down the road. Overall, the RS225 is still a fine performer, but if this HD result is representative of excursion below 100 Hz, then this means the production RS225's xmax may be a bit smaller than the prototype's. I would still say the nonlinear distortion numbers of the RS225 are, on the whole, better than the Dynaudio's on the strength of the spectral and numbers above 100 Hz. The production Daytons I tested were no worse than the Excel, though they cannot match the brute excursion of the SS8555.