Hi Jim,OK, back from almost a week in New Hampshire visiting the White Mountains. My legs are tired, my wife's legs are tired, and the kids are running around ready to go again.
I have used all of my Lowther drivers (PM6C, PM2C, PM6A, PM2A, and the three DX's) in the ML TL at some point in time and they all work very well. The lower line Lowthers (PM6C, PM6A, and DX2) produce more bass while the higher line Lowthers (PM2C, PM2A, and DX4) have more detail and high end. They are all pleasing it just comes down to what you want in the way of response, all require the correction circuit. The DX3 is kind of in between the extremes representing a nice compromise between the two sets, good bass and detail.
Hope that helps,
Martin
P.S. Don't forget to shorten the port length to the value shown in Project #4.