odd question about stand-mount speakers

Is there any reason you shouldn't turn stand-mount speakers upside down and listen to them that way, as long as you use some kind of vibration control/decoupler between the speakers and the surface they're placed on? The reason I ask is because, at least in a near-field setup, I would think having the mid/woofer ABOVE the tweeter would enhance image height/size -- assuming the tweeter is kept at ear level. (A couple of asides: I don't currently have bookshelf speakers, otherwise I would experiment. Will likely be buying some in the near future though. Also, I know that there are some stand-mount speakers that place the mid/woofer above the tweeter, but the vast majority do not -- most of the ones I'm interested in do not.)

Sounds like the old JBL 4311 studio monitors that when they stood upright the woofers were on top. The only problem with flipping speakers upside down is that you’d interfere with the tweeters output and dispersion which may not give you a good soundstage for one thing..interesting though. For near field listening it may be fine though. Worth a try. 

As long as the tweets are at ear level, it probably shouldn’t matter much.

I like Elrod's response, and would like to include that component placement is done in a certain way to achieve certain results. I don' tthink you will be going to jail if you turn your speakers upside down. You likely also cut the labels off of your mattress and no one has knocked at your door yet. On the other hand you just might lose out on what the designer intended and you Paid Megabucks for to begin with. Why not just buy a speaker that was designed that way to begin with. At least they have taken design factors to mind when they created their design and it might just prevent you from throwing your cash out the rear window!
 It is like the person that purchases a Lamborghini and then wants to put a Volkswagen engine in it. or at lest driving your brand new Lambo around in reverse all day long.

"As long as the tweets are at ear level, it probably shouldn’t matter much" -- that's what I was kind of thinking. If tweeter is at ear level whether right side up or upside down, then either way the same output should reach your ear from each driver at the same time, with the only difference being the direction from which the mid/woofer sound wave arrives at your ear. But sonics aside, I was also wondering if there is any non-sonics-related reason I shouldn't try this -- for example, would it be bad for internal parts to have gravity pulling on them in the opposite way. (Thanks for the replies, everyone.)

 a good speaker was designed to be used the way the designer tells you.

This is a pretty strong point. If a speaker is well designed, it is run through many paces. Many things are considered in positioning tweeter and woofer. Of course, that makes assumptions about your listening position, but they factor that in.

The effects of upending a speaker are variable, because of the factors mentioned above and which speaker you're upending.

Listening is surely a good thing to try. Do you like it better? Damn the torpedos!

Using an analyzer such as Room EQ Wizard is another path toward understanding what is happening when they're upside down or even on their side.