Storage of other speakers in the room, shorting them while not in use? Myth or true?

Back in the day, Ivor Tiefenbrun (Linn Systems), was very adamant that there be NO other speakers in the same room as his speakers being auditioned.

Even the speaker in a landline telephone could cause interference.

I can see sympathetic vibrations from the cones messing with your sound, like passive radiators, but not the pos. and neg. terminals. 

All the best,
Nonoise

Here is the experiment--take an unconnected speaker and push on the woofer cone to feel how much resistance to movement there is.  Now, connect a wire between the positive and negative terminal and push on the cone.  You will feel resistance increase (the now completed circuit will create a magnetic field  that resists movement).  I have my doubts that this will make any real difference in the sound in the room, but, this at least explains the theoretical basis for the practice.

Some lite reading:

A bunch of active speakers are not going to suddenly start producing notes because another pair of speakers are playing near them. Now if you stick a bunch of passive radiators in there it could be quite different.