Your room observation surprises me actually. I used Altec 19’s and 604’s in the same small 11 x 17 room (but at different times and systems) and felt the co-ax was much better suited to that small space. I love the 19’s but feel you have to get pretty far back from a large horn design before they really click in.

I’ll be building a larger horn system this summer (Altec 902 on a 400Hz round wood tractrix and Altec 416-8A woofer) so will get to try this comparison again. Results may be different in my current system and dedicated 12 x 22 listening room but I can’t see ever giving up my 604’s, even if demoted to another room.

Keep us posted on future ‘704’ observations.