When I bought a set of Heresy IVs to replace the IIIs I was impressed by the IVs better construction and thought the porting for 10hz lower frequency response was a great idea (although I use 2 REL subs in this heap, so...meh...). After listening to them for over a month with a frown (figured they were still breaking in), I narrowed the main issue down to an upper mid "honk" or aberration in piano music mostly as I listen to a lot of jazz piano trios. Man...I wanted them to be great, but put my trusty IIIs back in a realized how much better they sounded. More coherent, smoother...just better. Damn. I think the IIIs mid horn is simply better...titanium instead of plastic driver, more complex horn throat design...or something. Sold the IVs, still very much enjoying the IIIs.
