I purchased a pair of mint used vintage Electro Voice LS12A 12" 8 ohm full range drivers from ebay. I would like to incorporate these drivers in a pseudo Pi alignment. Unfortunately, I have no specs on these drivers. Can you help me?

1) Any ideas what type/size enclosure size will work best?
2) Would you use a helper tweeter (piezo or EV T35 or other)?
3) Does anyone have the TS parameters for these drivers?

Many thanks,
BobCat

Search the archives for "Woofer Tester". You'll find ways to measure the speakers with a signal generator and meter or scope, a dedicated woofer tester or a PC program like Speaker Workshop.

>> 1) Any ideas what type/size enclosure size will work best?

Depends on the parameters, but almost everything works well in a π cornerhorn. That's my favorite and it gets my vote. Then again, since it looks like you are going to use the EV's full range - well up through the vocal overtone region - You might prefer to make a standard bass-reflex three π speaker with them.

>> 2) Would you use a helper tweeter (piezo or EV T35 or other)?

Can't say without seeing the response chart. If response is good to 3500Hz, then the KSN1038 might work for you.

>> 3) Does anyone have the TS parameters for these drivers?

Someone else here might but I don't, sorry.