Jbl 2405如出現問題，通常是否同音膜有關？内部金屬圓形銅或片？ http://www.ebay.com/itm/JBL-D16R2405-Replacement-Diaphragm-Mint-in-Box-/160894078271?pt=US_Pro_Audio_Speaker_Drivers_Horns&hash=item257608cd3f