The beauty behind the A4 filter implementation is that the bass (especially sub-bass) is never really lacking. If anything, LZ could have omitted the Blue Filter and opted for an in between the Red and Black because the Black Back filter really eases of the sub-bass (read: considered restraint while remaining in the picture). That's probably my picky mind talking out loud.
I simply enjoy the energetic presence of mids of the Green Front. The Red Back handles the exceptional bass department, and there the mids can really shine with great presence and energy...I don't hear any recession whatsoever. So yeah total like!
SAFE TO SAY: Any lurker/inquisitive mind reading this: A4 is for those that want a quality hybrid without having to fear any fatiguing highs! Bonus points for ya!
Ok, got give the Red/B and Green/F a trial. I have really enjoyed the Red/B and Blue/F just seems so open and clear