Hi,i am a newbie,i also recently just bought a pair of la scala al4 (k77m +k55x)the woofer is k33 (round magnet), i also had almost the same experience ,one speaker is punching really ok ,also goes down i guess around 45 Hz,and the other one only punching with rattling noise ,i opened the one with problem ,driver almost loose ,i tightened it up ,also aded 4 more screws ,the gasket on the bottom panel in very good shape ,the rattling is gone ,but it is not the same bass like the other one,any opinions ?thanks ,Gabriel