hello for the 3 point planes concept to be accurate the 3 cones must be placed in a exact perfect triangle configuration. Now this is easily accomplished with light components or speakers but try it with a pair of 485 pound Dunlavy 5 speakers its really not possible. I would recommend using 4 cones in situations like this, especially if your in California.
3 or 4 cones under speakers /cdp which better WHY
Most cones come in sets of three but some also come in sets of four . Whats the lowdown on cones I am thinkg of trying tem under my speakers and CD player . Thanks for your time!