I have been really enjoying reading about subwoofer builds. I am now in the planning stages for a home theatre room. I was wondering about IB subs in a 4x Vas box. Is there a huge improvement to bass tightness and low frequency capacility if I build an IB driver in a 4x Vas box or is the difference not worth it. I don't really have a space issue, so box size is not a problem. I just want tight clean low bass. I considered a real IB solution but can't make that work.