Can I hook up two amps to the same speaker?

Interesting thread. I actually do this with my set up, without a switch box. So far, no problems noted. I've got the Gallo sub amp hooked up to the secondary voice coil input speaker terminals, and my tube amps connected to the primary voice coil inputs. If I'm going to leave the system on all day and not be in the room critically listening, yada, yada, I'll sometimes save tube life and swap the sub amp leads into the primary voice coil input on the speakers, switch the low pass filter off on the amp, and turn the tube amps off. I terminated the speaker cables form the sub amp in banana plugs for ease of operation when doing this. Is it a general consensus of opinion that I may be damaging my very expensive Bruce Moore tubed power amps by doing this? I always have them OFF when running things this way.
Thanks in advance for the replies,
David

In case anyone else stumbles across this thread, as I did, I just talked to a friend who's a former Bruce Moore engineer, and he confirmed, even with the tube amps off, the transformers will send a high AC signal to the plate and screen grids on the tubes. The tubes are designed for that, but not with the power off.
So, I'll end this practice.

Rolloff, glad to hear that my orignal thread may have saved you from disaster. Seems like it has...peace, warren :)