The difficulty in answering your question is that you refer to all three devices as "speakers". We're trying to help, so if you are offended, it was unintentional.
Only one (the 760) is a speaker. The others are not speakers, and trying to use them for unintended applications might result in damage, and definitely will result in disappointment.
The amplifier and speaker combo, the "Spokesman" can be used, as Sam said, as a one-way voice announcing device, if connected across the T & R of a manual or dial-select intercom. You can either switch its power supply or its voice pair input.
The Interphone unit can only be used in conjunction with other compatible parts, most of which, if even available, are expensive and made of UNobtainium.
If you have an application in mind, tell us what you want to do, and we'll tell you what to use, and how to find out the wiring schemes. Learning what the different devices are and what they do is best done by studying the BSP's, most of which can be found on-line.
Last edited by Arthur P. Bloom; 02/04/13 11:29 PM.
