I bought them from Aliexpress...Nobsound-like...
No problem...
4 sets of four boxes....
I used them one set for each speakers...With the 7 springs...
Four boxes under my speakers (20 pounds)
Four other boxes on top of the speakers with on top of them around 80 pounds of concrete
Under all speaker i use a sandwiche of different materials( quartz-granite-sorbothane-cork-bamboo) to isolate in better way each speakers from all the gear on my desk...
The load which damp each speaker is finely tuned UNDER 1% of precision (or near100gram of variation) by EARS to damp each speaker positively...
The difference in asymmetric compression between the 4 boxes under the speaker and the 4 boxes on top of the speakers, with a difference of 20 pouds in compression help decrease resonance effects...The magic is all there compared to 4 boxes only under the speaker without damping load and without a supplementary 4 boxes under the load...
It is relative isolation of vibrations with fine tuned dyssemetrical compressive force applied for resonance control...
Cost nothing...
Almost nothing, compared to anything which will beĀ supposedly "better" but not by a so great margin .... This compare to anything using springs....
Using the way i use it, it is optimal with this type of springs....
Better exist, but my ratio S.Q./ price is my rule.....