I've bought one design from him more out of curiosity than anything. He came up with a very similar box tuning and size as to what i planned on using to reach the goals I outlined for him. Lol, IMO, that means he knows what he's doing. He's also capable of using acabak, which puts him ahead of most of this forum (no offense, but modelling complex enclosures is really only possible with honresp or acabak) For the 50 bucks he'll charge for a design though, I'd still just buy a passive radiator lol. I can help you tune those for free.