This is an update from an earlier thread dated 9th of April.

I decided to put silicone sealant on the outer edge of the makeshift Passive Radiator fitted it back in its hole and waited for it to dry then put the Aiwa CS-880 box back together, switched it on then turned up the volume and gradually added bass then the big test I then put on the DSL switch bwoooooooy!!! did I hear a difference in sound enhancement on the lower frequencies,that middle Passive came alive such a difference. I'm so glad I made this choice of using silicone sealant to pad out the gaps around the Passive.