Mounting Speakers On A Furniture Dolly For Mobility

It will affect the sound. Everything matters. Will it deteriorate enough to negate the utility you require? Probably not. You might add a more suitable platform on the dolly, like a paving slab.

If you have to move them then you have to move them.

The biggest consideration for these setups is to make sure that there is no rocking of the speaker at all.  You want to be able to press on the top front to back and make sure there is zero tilting going on.  Also, you do want to use locking casters.

Also look at low profile platforms. Some have feet for stability. 

Unfortunately most speakers come with spikes and there are many specialty products like Podiums that significantly improve the sound even more. Using furniture dolly’s will have a performance hit… probably a pretty big one. 
 

Could you bribe your wife with a diamond braclet or something to leave them in their best position… which typically takes days or weeks of experimentation to find and 1/4” can sometimes make a large difference. 

Why not? Ive seen pictures of big Klipsch speakers on these. Be sure to lock them down some way, at least here in SoCal, an earthquake could send them flying across the room pulling amps down with the cables etc. heh. 

It will sound terrible.  Anything you put speakers on affects the sound.  Anything.  In my pro side, people often use road cases on wheels for stands- this sounds awful as the box resonates, the wheels resonate..  

Mass is your friend with stands.  You could buy sound anchors (sand filled heavy steel) and adapt them with wheels? 

I’ve found that the height of the speaker from the floor is a big factor in sound quality, especially in the bass.  Higher equals less bass and fullness. I don’t think this is simply a matter of driver height in relation to your ears either. Speaker designers factor the space between the bottom of the cabinet and the floor in their measurements and design. I prefer to keep my speaker height and footing like it was intended whenever possible.  This applies to other components as well.  I’ve tried it, I’ve heard the differences, I almost always prefer the stock configuration. 

Big negative  loose bass detail , definition , stage and overall detail.