Erik and I may disagree on some of the finer points of subwoofers, but we both think they can be well worth messing with.The disagreements are not on finer points. They are on the basic facts.
It's no secret that Duke is a proponent of the so called DBA bass technology. Erik however is an opponent of this. Here is what Erik has to say about it:
I am no longer a fan of this idea due to the fan boys and how cultish they have become.
Please read details directly from the vendor as I am not a fan and therefore won't do it justice.
In this thread, here is what Duke had to say about the measurements OP posted up:
Your measurements look to me like they are in the ballpark for a variable-frequency second-order lowpass filter.Here is what Erik said
No, the measurements do not look like very good representations of crossover behavior when changing the crossover point. However, since there are two subs involved, I can’t tell what is going on.In conclusion these are diametrically opposed views. They are the worst of enemies and any suggestion otherwise is disingenuous.