Hi I just joined this group 5 minutes ago.
I can tell you what you have.
Those POD-shaped speakers are normally used on a "Background Music Ceiling Speaker System".
All this means is, You have a large number of ceiling speakers installed all throughout an establishments ceiling area, maybe 20 - 50, for example. To keep the loss down on the long run of speaker cable, the amplifier usually has a transformer added after the output terminals. This takes the 8 or 16 Ohm output and steps the voltage up to a much higher level that the normal 8 or 16 ohm terminals deliver to a single speaker. Since the voltage is much higher, the current is just the opposite, much lower. The higher the current in a long speaker cable, the more power is lost in the run, which is bad. The principal is exactly the same as what Nikola Tesla devised for our "Electric Power Transmission System" which delivers power from electric generating plants over a great distance to our homes. Yes Tesla was a genius!
Just like the generating plants incorporate a "step-up" transformer to increase the voltage to feed the wires hung on giant insulators on the transmission towers, your amplifier would have a step-up transformer to feed, for example, the 70 volt audio wire that "daisy-chains" or hops from each speaker on the ceiling to the next until all are connected. I am describing a background music ceiling speaker system, not a home HiFi system.
Now lets say that the establishment wants to adjust the level of some of the speakers, well many types of ceiling speakers sometimes have an adjustment knob built-in for adjusting the loudness. Changing voltage taps on each speakers transformer will also effect the level.
You probably haven't noticed it, but each of those speakers of yours has a transformer inside the case, which is wired to do the opposite of what the amplifier's transformer does, which is to step down the higher audio voltage to lower level, which intern steps up the available current for driving the 8 or 16 ohm speaker within.
Ignoring all the above.... what you need is an "8 ohm to 70 volt line transformer" on the output terminals of your amplifier.
Alternately, you might be able to just open the case on each speaker and disconnect the transformer completely, "bypassing it", by having the connection directly to the speakers voice coil terminal instead. So the transformer will have all the wires disconnected from the speaker and the speaker terminals, which now connect directly to the voice coil terminals.