Putting weights on speakers?

basically you added mass and therefore reduced the natural frequency of the enclosures. 
is there a limit to heading in this direction where the sound becomes something we do not car for?  
example- Magico aluminum enclosure speakers and subwoofers.  
somehow the bass response of these speakers was foreign and disorganized.  the midrange and treble were phenomenal but the bass was horrible.  i suspect that the enclosure was too rigid and actually causing the drivers to resonate.  just a guess.

if we made enclosures from concrete, would the same thing happen?  

i believe we are used to a certain amount of cabinet resonance and like what it does for the sound.  

mahgister, what happen’s in the audio room stay’s in the audio room. I imagine this is the look your wife give’s when you explain your tweeks. 🙄

You are right on the spot.... :)

But she know i love my audio system much then approve me without saying it too much openly....

By the way one of the most precious thing to have is a room only dedicated to the audio system.... With this you can made many improvement which are impossible in a normal room used for socializing reason....

for example for the active acoustical controls:

a- I use a grid of active metal resonator (50)
b- I use 20 Helmholtz bottles of different sizes
c- I use a grid of connected stones and crystals
d- I use a grid of cheap 10 Schumann Generators modified with crystals and stones...
e- I use a grid of 90 little bells or cones of 2 different sizes(7mm or 9 mm)

and many others things like passive acoustic materials etc....

I also has modified all the main electrical grid of my house.... :)

mahgister, your tweaking program is far beyond my comprehension. I'm sure it does wonders!

MAGICO makes some of the best speaker enclosures made and the bass is accurate with the right cables and amp and preamp.MAGICO makes some of the best speakers such as Q3s, M3,M2 these are some of the best speakers with great soundstage,detail,depth, and great bass as well.However there are other great speakers out such as Tidal and Vimberg.

Pour molten lead over the top. Much better than concrete; better aesthetics and makes a strong  connection with the Earth's magnetic field. See page 34 of my recent tome.  
"Pump up the Volume or Weighting in a Rubber Room."