▁p ig gy back ing , ▁in ▁which ▁the ▁upper ▁c ym bal ▁is ▁bell ▁down , ▁the ▁lower ▁c ym bal ▁bell ▁up , ▁and ▁a ▁spacing ▁felt ▁is ▁used ▁between ▁the ▁c ym bal ▁b ells , ▁prevent ing ▁any ▁contact . ▁ ▁P ig gy back ing ▁ ▁P ig gy back ing ▁is ▁a ▁method ▁of ▁mount ing ▁a ▁spl ash ▁c ym bal , ▁mostly ▁restricted ▁to ▁small ▁spl ash es , ▁by ▁simply ▁placing ▁it ▁invert ed ▁above ▁another ▁c ym bal , ▁with ▁which ▁it ▁shares ▁the ▁mount ing ▁b olt ▁and ▁its ▁she ath , ▁was h ers ▁if ▁used ▁and ▁wing nut . ▁A ▁spacing ▁felt ▁is ▁normally ▁used ▁to ▁separate ▁the ▁c ym b als , ▁serving ▁as ▁the ▁top ▁felt ▁of ▁the ▁lower ▁c ym bal ▁and ▁the ▁bottom ▁felt ▁of ▁the ▁upper ▁c ym bal ▁in ▁order ▁to ▁avoid ▁c ym bal ▁crack ing . ▁▁ ▁There ▁is ▁an ▁essential ▁difference ▁between ▁this ▁technique ▁and ▁stack ing . ▁A ▁c ym bal ▁stack ▁produces ▁a ▁different ▁sound ▁to ▁that ▁produced ▁by ▁either ▁c ym bal ▁individually . ▁The ▁p ig gy back , ▁like ▁the ▁double ▁stand , ▁is ▁primarily ▁a ▁method ▁of ▁mount ing ▁the ▁spl ash ▁c ym bal , ▁without ▁producing ▁any ▁major ▁difference ▁in ▁the ▁tone ▁of ▁either ▁c ym bal . ▁ ▁Adv antages ▁of ▁p ig gy back ▁mount ing ▁are : ▁ ▁Re qu ires ▁minimal ▁mount ing ▁space , ▁and ▁therefore ▁produces ▁a