The inside of an Altec 291-16A compression driver

What a compression driver looks like on paper.


Rear cover of the chassis that holds the diaphragm.


The diaphragm removed for inspection (a bit of dirt).


The rear plate without diaphragm. Here you can see the entry
of the phase plug(s) and the airgap for the voice coil.


Phase plug removed for cleaning and re-centering.


Front view close-up of the phase plug. Quite impressive work!!!


Maybe this gives a better idea.


Ah, I've been cheated. The Alnico 5 magnet is smaller than you
would think judging from the outside.