Subfloor wobbly or bouncy problem

Everything in the room has an earthquake effect but no creaking.
I don't know how to make the floor stay still.

Do I just put another layer of plywood on top? My subfloor is 20mm or maybe more below the door level and kitchen area.
Is underlay not used for these problems?

 

Screw down 18mm ply to subfloor to strengthen it.

 

I'll try that.

 

Is there a lot of play in the floor?
Is it poss that a joist has left the wall plate or a tassel wall has collapsed ?
If there's a lot of bounce in the floor the root cause needs to be investagated.

I have come across this before when a customer complained that the records jumped when they walked across the room. ( showing my age)

 

45s or 33s

 

78's......

 

Walking around is fine. Just jumping or running in the house is not. I do exercise in the house too.

 

Depending on the span of the joists they may need further bracing or doubled up on. Then proceed as merit (above) says.
Without seeing the floor its difficult to give specific advice.

 

All of the above. And when records were more like bakealite (spelling) and very brittle