JBL Factory Speaker Replacement Diaphragm D8R2431, 2431H, 339894-002X, and many others JBL Factory Speaker Diaphragm Part # D8R2431 for JBL 2431H drivers. Specs: Comes with ferrofluid and mount kit Factory AUTHORIZED service and parts. FREE technical support. FAST & FREE shipping to any USA address. SUPERIOR quality, LARGEST selection, and the BEST prices!