Donnyfl Tatsu on

I just received my tatsu in the mail today from UA so I downloaded a decibel meter app on my phone and went out shooting with both the stock moderator and the Tatsu. I was blown away when through the testing I was getting 89-91 decibels with the stock moderator and 97-99 with the Tatsu. I didn't move my phone at all between shots just reset the high measurement could this be because the app is unreliable or that the donnyfl tatsu doesn't quiet the Wildcat MK2 compact any compared to what comes on the gun stock? The group I shot with it at 50 was tighter than anything I had shot with this gun prior. I think it did improve accuracy though. 
 
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 Mine was way quieter with the Tatsu also! And the groups tightened up as well!