Lowther PM2A
Comments: This is a classic Lowther design. It has a better bottom end than the DX55 and will play louder but it suffers a bit from the larger cone size in the treble. A little network tweaking trims that out by about 6dB and the result is better sounding than it looks on paper. Jon Ver Halen points out that it's better 15 degrees off axis and asked me to note that this is the 16-ohm version. Lots of people swear by this driver and if your taste is a little different than mine, you might prefer it to the DX55. The DX4 is probably the best compromise between the two drivers at slightly higher cost. The PM2A lists for $1595/pair.

Lowther DX4
Comments: Jon Ver Halen at Lowther America claimed that the DX4 combines some of the best attributes of the PM2a and DX55 and I'm very inclined to agree. In my opinion its top end is still not quite as exquisite as the DX55 but it is significantly better than the PM2A. Again, the high end is said to be better 15 degrees off axis. Here we see the 16-ohm unit mounted in the KleinHorns where it gave very satisfactory performance. Measurements indicate a slightly better bottom end than the PM2As and of course one that's better than the DX55. The DX4 costs $1695/pair.

Fostex FE108E Sigma
Comments: We borrowed this from Ed at the Horn Shoppe and as far as I can tell, he has the world's supply by virtue of buying up all he can get. This is one of the smaller units of the latest editions of the Fostex banana fiber cones. An obvious comparison would be to the similarly sized Lowther DX55. The DX55 has much higher efficiency and a more detailed top, the Fostex counters with slightly better bass extension. Madisound sells them for $85/each. At that price, it's easy to check it out for yourself. I gather that it really prefers a rear-loaded horn, not a sealed box, but you can use it either way with good results. Note: I did not get a picture of the FE108E Sigma but it looks just like the FE208E Sigma so I simply shrank a picture of that.

Fostex FE166E
Comments: The FE166E is an extremely nice driver with a very detailed and smooth top end. I was going to give it short-shrift praise until Terry Cain sold me a pair of his Abby loudspeakers which use the FE166E. Spending a couple of days with the Abbys showed me that Terry's Voight-Pipe type enclosure produces more bottom end than I would have imagined possible. Hence this Fostex unit was instantly upgraded to "best possible $61 driver".