Yes, below 200hz it acts like dipole, so I have to boost below that frequency. I like dipole bass very much, but also want to have good integration. This alignment gives both and it has the other advantage that cardioid can presurize the room like a monopole. Concept has both advantages of a dipole and monopole.
Yes, I first used a dipole configuration with DSP. This cardioid alignment has a directivity pattern that has a better match to a waveguide / horn. Goal was constant directivity and good integration, below 200hz it acts as a dipole again.
The only thing that you always can complain about regarding waveguides is that you want them to go lower! On the others hand than issues arrive at the high frequencies. Anyway integration with the LO15 is excellent, so I think the SEOS-15 is the optimum waveguide.
It is a real different way of listening to music when CD is applied, much more detail due to lower room influences. It just sounds like it should to be, not over detailed or shouting, but very involving.