how is the topic of an event computed if the event accepts a struct instance?

my event accepts an address for the first argument and for the second argument an instance of a struct containing an address and a uint32. i tried

echo -n 'MyEvent(address,[address,uint32])' | keccak-256sum | head -c 8

because that's a JS/TS-like notation which usually works pretty well with solidity

i also tried

echo -n 'MyEvent(address,(address,uint32))' | keccak-256sum | head -c 8

because i found an answer on SE saying to use round parenthesis for computing function identifiers if the function accepts a tuple instance

i also tried

echo -n 'MyEvent(address,tuple[])' | keccak-256sum | head -c 8

because that's the type i found in the artifacts file generated by remix

but none of these work out to the correct topic

how do i compute it?