Inactive speakers in the room...any effect?

I've done the experiment, and in fact have done it many times. I did it with unsuspecting customers at the audio shop I used to work at, and didn't even tell them that I was doing it, or anything. I would tell them afterwards, and they were all typically amazed that it was just another little speaker in the room making the difference.

We had a single speaker(pair) system listening room in the shop for demo purposes of the higher end systems. We'd do the demos and try some different components and speakers until we found something the customer liked pretty well. Only the active set of speakers was present in the room. Then I'd go out of the room, and come back with a cordless telephone handset, like I was just finishing up a call(phone turned off). I'd put the phone down on the small table next to the listening chair, and then put on another record. Almost every time, the customer wondered what happened to the sound of the system. There were no apparent changes to the components. After a little conversation about it, I revealed that I had brought the phone into the room and put it on the table, and that he was hearing the adverse effects of the re-radiations of sound from the telephone speaker. Then I'd take the phone out of the room and play the record again. Sound was magically restored. Then I explained why a single pair of speakers in the demo room was important for auditioning purposes. I probably did this over a hundred times, with as many different customers. To this day, I never have any other speaker in my listening room. Not even a television speaker or computer speaker or a telephone speaker.

Now I'm not going to say that everyone will notice this in every home listening environment. But in a dedicated room with good setup, and a reference grade audio system, it is definitely a factor. Maybe a somewhat minor factor, but an audible one.

Some may doubt this, but I am relating to you a real life experience that we did use in our audio shop for years. I have first hand experience with this, and knew what I was doing. People may nay-say or try to come up with some kind of reason why this can't happen, but I'm here to tell you that it does happen, and is repeatable as per my experiences.

Eldartford, perhaps I was not clear in my original response, But I am comfortable in suggesting that the first 3 criterion were fullfilled ( if not quite a dozen times, quite close, further more some the listeners had the opportunity to do this on more than one occassion spanning a couple of days). As for the statistical tabulation and analysis, I think the unanimous response satisfies that criterion. Do I think that a unanimous response will always be typical, heck no. I do think most people can discern the difference.

Tom, did you ever try putting a pair of inactive speakers in the lower corners of the front wall behind the active speakers?