Using active ping at high speed
 

This is a general question. Why does the active sonar got washed out like passive one when the sub travels at high speed? I thought active sonar is not affected by the surrounding water rushing past the hull.

The active sonar uses the same transducers to receive the return as the passive spherical array, which washes out due to flow noise around the bow and hull.

Since the active sonar on a torpedo still functions at 50+kt, it must be using a different transducer rite? Speaking of torpedos, how come the sonar systems on torpedos, either passive or active, can still listen, search and find their targets at high speed whereas the sonars on subs get washed out?

Ya got me. The ducer in the torpedo is designed to work at high speeds, and specific frequencies and it has a narrower angular range or cone than a spherical array.