Thoughts on wireless subwoofer.

Just looking for thoughts on whether this idea might actually work!

I have an Ayre ax7e integrated amp which does not have a sub out so best connection to a sub would be from speaker terminals taking care on connections as this is a fully balanced design.
This has been discussed previously in other threads and with Almarg.
However in my system hooking up a sub like this AND alternatively using the tape out RCA resulted in a very audible ground hum especially on phono.
This I could not get rid of so abandoned the idea.

Now here are my thoughts anew.

What if there was no actual physical connection between amp and sub? Surely then I should not suffer a ground loop hum?
Started looking at wireless subs and there are a few hifi orientated brands than run of the mill HT units.
One in particular I have been studying is the Martin Logan Dynamo 700w. This has a built in receiver and uses a transmitter that accepts RCA inputs and transmits on Bluetooth to the sub.

Sounds like it should work but.....

Anybody see any downside or has actually used a wireless sub?

Thank you.