Gigantic subwoofer. Value?
It was most probably used to produce the lowest notes of an organ. That "Patrician" driver, if it is any good, could be worth a fair bit of money, possibly several hundred dollars. In good conscience, you owe it to the church to first find out whether or not the driver is supposed to currently be in use but isn't for some reason. Secondarily, if it is not in use and can be sold, the church should get All of what the driver sells for. Whether or not the church's current administration knew of the driver's presence, it IS the property of that organization and You Do Not have Any rights to it, Period. As for testing such a driver, be Very careful. Speakers from the Patrician's time did not handle a lot of power and can be easily ruined by someone trying to find their relative limits. Don't connect it to an amplifier at all until you do some research on it. Learn First, Think Second, Test Last!
That is not a subwoofer. It's just a very large full range p.a. speaker. Build a cabinet for it and have fun playing your radio through it.
https://www.manualslib.com/manual/43606/Electro-Voice-30w.html As told in the manual, it is a large,30 inch diameter driver specifically made for bass reproduction and should be used in conjunction with a crossover set at about 100 hz. It is not a 'full range PA speaker".Electrovoice recommends two CROSSOVERS of their own manufacture, one the same as is used in their Patrician speaker system, which also uses the model 30W driver. They demonstrate three cabinet types as well as in-wall mounting instructions. As the unit is driven by a nine pound magnet structure, You can be certain its cost is not insignificant, and doubtless its retail price can be obtained from Electrovoice. It requires a minimum of 60 watts to drive its motor appropriately, as per the manual. Its purpose is to create much louder than normal bass passages, to make up for human hearing, which is quite insensitive to deep bass notes. It requires a sealed, not ported enclosure, due to its type., As to its worth to you personally, consider that it is almost of no worth sonically without a proper enclosure and crossover. A internal cabinet volume of 300 cubic feet(!) is needed to achieve a resonance point of 20 HZ. This enormous structure should be braced with 2x4 struts every 24 inches or less to control cabinet rattles and interferance(!) The best practice solution from Electrovoice would be one made of concrete block. In the Patrician, mass loading is used in leiw of this giant, sealed space. The physics and woodworking skills required for this solution are extensive.
The Oracle of Omigod
Go to Ebay and look.
30 Watts is not that big, if it's brand new I would pay $25-$50