Equipment rack behind speakers: bad?


I will be moving into a new house soon and will be forced to place my equipment rack behind my speakers. Is this bad acoustically? The rack has three shelves (vertically) and is sized to handle two components side-by-side. I would think that it would act as a facsimile of a diffusor, as the rack has metal grills on each end (and center between components) and these grills are perforated with many small holes. I guess the only other thing that I have to worry about would be vibrations from the usual bass build-up near the back wall affecting my equipment. Your advice is appreciated!
fairleypm
I am with the long ICs preamp to amp school w/ short speaker cables. Especially if you have a TT. My best of Axpona this year had all CAT tubes w/ tech das III TT between the speakers. JV / TAS gave it a small critique.Given room/ show conditions AND that it was between the speakers; I think it should have been JVs best of show. Many dealers show this way for convienenceĀ 
One more comment. If you do go between the speakers as it sounds like you are, be sure the equipment sits behind a line drawn between tweeters. If it does not, it will effect the sound-staging. The further back the better.
Fairley, I also have a narrow 12' room. But even if it were wider, I think the best solution, both in terms of user convenience and system (electronic) layout, would be to put the amp(s), subs, elec. x-overs, etc, between the speakers and all the other front end stuff to the left or right sidewall, even with the listening position. You will use long ICs from preamp to amp(s) and short speaker cables -- which is the preferred way to do it IMO.
Thanks for your responses. I'm mainly concerned with acoustical not vibration problems, as the floor is cement with carpet over it. I also have an isolation platform for my turntable ... I want as nice a soundstage as possible, but my room is too narrow (about 12 - 13') to put the rack to the side of the speakers (unless it's in the corner behind the speakers, which for the reasons you all note above, I didn't want to do). The room has 8' ceilings and is about 25 - 27' long. Not perfect, but not bad either. Thanks again and good tidings to all!
Nsgarch if right on. If the rack is in the corner the vibration issues increase two fold. In acoustics every point two planes meet the energy is doubles. This is why acoustic treatments start in the corner where the ceiling joins. The energy is tripled at this location, as is the fact for the floor. Setting up a rack within this "higher energy" could begin to cause major issues with vibration. If you must set up in the corner, you really should consider adding base traps at the corners and putting the rack at an angle???
Done it many times (see my system). Best if the rack is centered behind/between the speakers since bass tends to build up in the corners, not the middle. And anyway, at the boundries (like the back wall) the energy transfers to the wall itself (which is turning the wave around) but there's actually less air movement to affect your equipment rack. In the picture of my system, you'll note I even have a Target TT shelf bolted to the back wall (OK, it's a brick wall) but the TT had absolutely no vibes transmitted to it.

The only downside -- it's a bit further to walk, so get a remote volume preamp :~))
As long as your rack is open? I see no problem at all. If your rack is closed on both sides this could affect your soundstage.