05-07-2012, 01:10 AM
Apparently, it's called an "intermediate" AKA E17 base. It's a little bigger than a candelabra base. It hangs down below the chassis to illuminate the speaker so I don't think heat will be much of an issue.
Lots of options here: http://www.bulbtown.com/Intermediate_Scr..._s/312.htm
Lots of options here: http://www.bulbtown.com/Intermediate_Scr..._s/312.htm