The EPA does have a Noise Guide for Local Government, which states that amplified music falls under the local council and NSW Police's responsibility.

In that, Police have the power to seize the equipment. If OP can find out who it is, a written warning that if it continues a police complaint will be filed. I would also tell strata that they may be forced to allow police access to the floor in question in the middle of the night to seize the equipment if the fail to do anything about it internally to resolve the matter.

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Tell them they have 7 days to comply, and request the managers personal mobile number, so police can call it to gain access when you have another complaint.