Here are the crossection settings from the M2 preset for the D2430K on the M2 waveguide, published by 4313B:
http://www.audioheritage.org/vbullet...1&d=1369326015
and together with the (1st order electrical!) crossover and global EQ:
http://www.audioheritage.org/vbullet...1&d=1369326357
So obviously it *needs* EQ to reach UHF on a constant directivity device: around 10dB between 2kHz and 9kHz. Above 9kHz it seems to keep its level up to 20kHz (and maybe above), which is a phenomenon that already partially appears on the 2407H and other BMS designs.
Lets wait for distortion measurements now, to see the effect of that push pull design on 2nd order distortion! (which was the big drawbacks of BMS designs...)