Speakers and what's between them


Is there any objective audio data that mentions the possible negative effect of placing household objects (audio rack, furniture, large plants, etc.) between speakers? In other words, is it preferable, as a rule of thumb, to NOT fill in the space between the speakers with various "objects", or must every situation be considered in terms of the room and the speakers reproducing music within it?

Thanks to one and all.
recroom
You should keep sharp edges about 3 feet from speakers... a speaker placed a couple of inches from a TV screen with a 1 inch gap between the two will suffer edge diffraction and may affect mid range imaging and sound stage.

Apart from the above, no is doesn't matter that much in fact it matters less than what you place in front of your speakers or what you sit close too (close to a wall, corner = BAD). Of course the same rules apply as to any surface/furntiure in the room...strongly reflective surfaces (concrete wall) will not absorb bass energy but may reflect it well and therefore will not help to reduce room bass reverberation compared to a wall that is covered in shelves with books.
In my experience I had a TV in between the speakers and it collapsed the soundstage. I've now quit trying to play with home theater and I place my other components on the floor not on a rack between the speakers. This allows much more depth of the soundstage.
also you should keep whatever is between your speakers behind the front edge of the speaker