The assembly originally came from a lap steel guitar and the cover was actually a pair of horseshoe pickups which also formed a wrist rest.
In the 70s the horseshoe pickup was replaced, but the surround was retained.
Rickenbacker teleased a subsequent model, the 4004, which had no surround, but customers kept buying the 4003.
So, the reason it is so big is because that is what customers want!
Nope - if you plug into both, you may get no output:
Plugging a jack into the mono output connects both channels together.
Plugging a mono jack into the stereo socket connects the jack socket ring to the sleeve of the jack, which is gnd.
Therefore everything is connected to ground.
Incidentally, Ric did do one model of guitar with dual-mono outputs rather than the normal mono/stereo; I think it was a 620 variant.
Well, there are two amps there.
Alternatively, if it is a mono cable, then perhaps the owner only likes the treble pickup and uses the selector as a kill switch!
I think the Bass Bashes are great and folks are pretty good.
I might've cranked up my amp a bit at one when I was trying out a Barefaced 1x10 before buying it, but otherwise very civilised.
Sure - I have some earplugs and they are essential!
But the volumes being at a level where it is uncomfortable and you can't hold a conversation make it an unpleasant place to be.
I don't have the answer - maybe acoustic booths, loud rooms, or something.
I would also say that being in a relatively small hall with several cranked up bass amps is probably louder than a pub gig, or even a large venue concert.
As for the moan aspect, consider it feedback (haha - geddit?).
Well, when I went a couple of years ago, it got so loud that my whole head was reverberating and I had to go out.
There were one or two stands where folks were hogging the kit too.