Thanks for that info Mark, as usual, a stellar job at explaining how all this works.
I wish I could have done the floor but time was not on my side. It should be fine, closest neighbour is about 200 metres.
You can see the steady patience in his work! I've been known to be generous with glue, especially on horns. If you have a leak, you will hear it.
They are 20 Hz horns. From these you get ultra low distortion, very clean bass and virtually unlimited output. When the cone is barely moving, an entire room fills up with bass.