I encountered this curious problem with Fmod (1.09.05) equipped with Oculus Audio SDK (1.1.5).
The problem I encountered is as follows:
When I start my FMOD session, the program reserves 51 200 K of memory.
When I play a relatively complex sound from the session with 3D panner equipped, the total of 65 216 K of memory is reserved.
However, when I play much simpler sound with Oculus Spatializer equipped (Attenuation enabled, Reflections disabled), the total of 836 264 K of memory is reserved.
This effect is naturally forwarded to Unity project I'm working on. It also seems that the Unity doesn't take this into account when loading FMOD sound banks as the first sound that uses the Spatializer triggers the memory reservation, which in turn causes a definite lag spike in the runtime.
The most accurate cause for the problem that I can point out is a bigger merge we did in the project version control a while back. Naturally, none of the programs and plugins (OculusSpatializerFMOD.bundle for Unity excluded) are held in the version control so therefore they should be unharmed. After finding the source of the problem, I've re-installed the FMOD, its integration in Unity and Oculus Audio SDK plugins in both ends with no change.
Would you have some tips on how to fix this problem of mine? Until this problem manifested, I've been very happy using Oculus Audio SDK in our VR project and it would be a great pity to ditch it due to this relatively small but really annoying bug.