after adding the voice
in the steamvr.vrsettings file the problem is still there.
I prefer not to comment the friendship of other programs . In any case my problem concerns the compatibility of Piplay and SteamVR.
I followed the link instructions but did not relate to my hardware configuration.
My problem is not about the Oculus Rift, which has always worked well. It is about the Pimax 4K with the latest and the penultimate version of Piplay. I was not accurate. Let me explain: When SteamVR does not work I'm using PIMAX EXCLUSIVELY. The oculus are unplugged by the pc. I used the Oculus Rift to find out if the problem with SteamVR was a possible upgrade of Steam that had caused SteamVR malfunction with all of my HMDs. Instead, with Oculus Rift SteamVR works perfectly. It does not work only with Pimax 4K.