Marble to place speakers on?

Ditto to what Audio4fun stated on the benefits of marble, though I have heard dimensions of 4" additional on all sides to the dimensions of the speaker bases (i.e. 8" total greater dimension on all sides).

However, Duntech Sovereign speakers are about approximately 75" tall, 18" wide and 23" deep and weigh approximately 170 lbs apiece (I may be off a bit on these dimensions). Duntech Black Knight speakers for awhile came stock with a very heavy, dense base bolted to the main speaker similar to Audio4fun's stated method for his Sovereign.

Practically speaking, most speakers will have to settle for resting their spikes on a simple marble bass platform with the 2" larger dimensions stated by Audio4fun.

Also, I have been looking for marble for my current speakers and am finding it difficult to find a thickness in excess of 3/4". If you do find a source of a thicker marble please let me know.

By the way, expect to pay a premium for marble (or even granite). I am being quoted approximately $500 for two 25" x 20" x 3/4" slabs of polished Black China marble.

The best marble under speakers is the cheapest marble - ie. the marble with the most impurity. The impurity stops the marble ringing. Is is dolomite that is the impurity? I cannot recall - but I have tried different marble and the sound is better with the cheaper stuff.

Where do you guys get this marble? Just 3 days ago I put some ceramic tile 1/4"X 12"X 18" under my speakers.It was very cheap ($2ea.) and it was all I could find that would fit.I have my speakers spikes almost all the way into the speakers.They are out about 1/4" I hear no ringing or anything else other than deeper and tighter bass.I still would like to try some marble if I can find it.

david: most cities of any size have suppliers and fabricators of stone countertops, floors, etc. i have purchased over the years several "scrap" pieces of marble and granite from a supplier in denver. i've not used these under speakers, but i know from experience that pieces of marble of the "correct" size for most speakers' footprints are readily available. the prices will vary rather dramatically depending on the color and "purity" of the marble you want. as redkewi sez, tho, you shouldn't go for the purest stuff, e.g., white carrera. your choice of stone, and its relative purity, will likely be dictated by the color you want. the last piece of marble i bought was "green empress," which i used as a top insert on a muse model 18 sub; it was beautiful but i wouldn't choose it to mate with my current speakers. good hunting. -kelly

If I do bolt the speakers to the marble, am I doing away with spikes all togather hence adding mobility by sliding?