Instead of releasing all Ghosts one by one via Urns/Gravestones in each Household you can use the new "Release all Ghosts" Option on Urns/Gravestones. It will release all Ghosts without deleting them from the Family Tree. Ghosts that are in Households are not affected. "Get Urn for" will add a Urn inside your Sims Inventory which stores the Ghost Sim/Pet. This is helpful if a Sim dies off Lot which usually does not generate a Urn.
Normal Stereos and synced Lot Stereos have their own Audio Configuration File but they only added the normal one for the public Stereo Wall Speaker Metal. I checked all Audio Configuration Files in the SP17 Files and i could only find one which has the same samples, so i added this to the StereoWall Channel Metal instead. It looks like this let's all public Metal Wall Stereos play the same sample now.