My dad's left coda 9 speaker has been REALLY VERY quiet compared to the right one for a while now. When I open it's cover and gently press upon it, it works perfectly. My dad thinks that this part *points to the attached pictures* is the cause of this. We measured it's diameter (165 mm) and looked at this technical specification: http://www.kef.com/uploads/files/en/museum_pdf/90s/Coda_7_Coda_8_Coda_9_Installation_Instructions.pdf . The question is, is this part a "bass unit" or a "sub-bass unit"? As you can see in the specification, they're both 165 in diameter. Thank you for your responses :-) http://img826.imageshack.us/img826/7645/img0608tb.jpg http://img801.imageshack.us/img801/1347/img0609wk.jpg