Ok. I will begin with the Soviet projects them.
The first submarine I would discuss is the oldest 4th generation project we had, and probably it is the most interesting one for the Western reader. The reason for this is because it was a fairly unusual submarine type for the Soviets. The project 958 submarine (Afalina class) originated from the Soviet studies on how to protect our then vulnerable boomers, when they were patrolling in NA areas, the areas contested with the US forces.
The idea was to create two destrinct submarine types - an "AWACS" (project 693) submarine with advanced sonar, and the "interceptor" submarines (project 657) which would be vectored onto their targets. With the development of trully long range submarine launched ballistic missiles the patrol routes shifted to the friendly waters and thus the need for such a complex set up dissapeared. The requirement to engage hositly boomers on their home ground did remain, leading to the development of the project 958 submarine.
As you could see it had a large aperture conformal array, as well as large diameter bow spherical array and a long towed array. The armament was fairly conservative - 6 533mm tubes, however this was sufficient for sub hunting.
To keep the submarine survivable it's sonar signature has been substantially reduced, based on the insights gained from project 991. Some of the ideas from it, and project 991 were realised on the a far better known sub - the Shyka-B series (project 971 aka Akula class).