Using subs as speaker stands ?

If you are in a rather small space, you probably don't need two subs anyway. Get one and some good stands for your monitors. Place the sub somewhere in between the monitors for optimium soundstaging.

thanks for all responses, but the responses leed to another question, since some replies sugest that putting monitor on top of subs causes distortion in the sound waves,what about the aerial 10 t where the top modual sits directly on the base modual, also the tyler reference speaker does the same thing and I am sure there are others, if its true that sitting the top peice directly on top the sub section causes distorted sound waves, how do the above mentioned speakers overcome it, thanks all

Without doing the in-depth research on the specific models you mention, the bass units I've usually seen attached to the midrange/tweeter sections are 1) not independently powered (i.e., they are passive units) and 2) specially designed and braced to accommodate the match-up. One unit I have heard that had a powered sub-woofer in the same cabinet as the midrange/tweeter was the Definitive Technology speaker and it was overkill on the low end and dipping rather dramatically in the lower midrange/upper bass region. Was that a design problem? Don't know. I've heard many good things about similarly designed Infinity systems.

Place your hand on top of a sub-woofer and you can feel the vibrations. Place your hand on the cabinet of a speaker cabinet and you would not normally feel the vibrations. There are different design parameters that need to be used under the different design objectives. Stand-alone subwoofers are not designed to be physically connected to other speakers. If they were, they would likely require more space and more bracing in order to reduce the cabinet vibrations.

That's my top-of-mind response. I welcome corrections and expansions of the explanation. Good question. To expand on the question, are there speaker companies that attempt to physically isolate all of the independent speaker units? My experience has been that isolation and stability helps greatly (e.g., speaker cones or stands). I wonder if any company took it further?

Ozlfy is dead on. This stacking idea is not the way to go. I think you have some good information in these threads to make a decision. You may have to make more changes than you thought. The stacking idea, however, goes agaisnt resonance principles and the like. If you really want more technical data, email Audiopoints.com and ask for Robert. He will set you free.
Good luck.