Ans this is the same track with the sub kick taken out.

seen from Japan
seen from Türkiye
seen from Türkiye
seen from Jamaica
seen from Türkiye
seen from Russia
seen from Türkiye

seen from Maldives
seen from Canada
seen from Canada

seen from Russia
seen from United Kingdom

seen from Türkiye

seen from Ukraine
seen from Canada
seen from China
seen from Russia

seen from Germany

seen from United States

seen from Netherlands
Ans this is the same track with the sub kick taken out.
If you have some good headphones or decent monitors get them.
This is the first test recorded using the sub-kick. Sadly the first thing I hear is the terrible kick drum, but the sound is otherwise pretty good.
Listen to this then listen to the next track with the sub-kick taken out.
So some test data. The first spectrograph is the recording of a single kick with the SM58, the second the same kick with the Sub-Kick.
Straight away it is clear that the Sub-Kick has captured much more low frequency audio than the SM58.
This first test was carried out with the back of the device in place. The later tests will be with it off.