Personally I think hull sonar cones were OK. Only the sphere were seeing too much to the rear. So we (
) changed only Sphere and active sonar cones. Hull sonar is a substitute of towed in shallow water. Let it be this way. Phased array radars work usually in +/-60deg cone (more modern ones). If you wanted to have baffles from all sonars +/-60deg in the rear, hull cone would have to be only +/-30deg, don't you think it's little low ? Sensivity may drop on greater angles, but it's quite poor anyway...
P.S. About spherical and active cones - just though to take a look at 688i and Seawolf sonar array pictures (there is picture of SW sphere) and after this look I think again we are now right with reduced cone. Take a look and think how could the sound to the passive or from the active travel at angles greater than 120deg. It's clear that the hull (simply the "disk" sonar is mounted to) blocks field of view of the sphere at angles greater than about 120 degress, it's blocked for sure at 150deg (that's only 30deg from the rear).
By the way the SW sonar dome is much larger than 688i (and it is said somwhere that it's improved) so greater sensivity (and little lower min freq ?
) is OK. But Akulas still have bow torpedo tubes and much smaller cylinrical sonar, it should really have lower sensivity than even 688i sphere in realistic sim...