Dapol O gauge sound-fitted class 122 with improved drive train.

Initial running of my O gauge Dapol class 122 7D-015-006S with DCC sound and improved drive train.
I have to say the model is a beauty and runs perfectly - I am very fussy that my trains can run slowly and smoothly. The new drive train appears to deliver just that. Is there a downside? Yes, the sound is very very quiet. I have managed to find the sound cv for the Zimo decoder and taken that to maximum but it is still quiet and can’t be heard if any other sound locos are working. Does anybody know of a way to increase the sound? With the real-drive activated it will coast on idle until I bring it to a stop just like the real thing.