Driver is Dynaudio Esotec 17WLQ, 6-1/2" mid bass in reflex enclosure about .35cf, f3 about 45 Hz, active crossover 2nd order high-pass @ 80 Hz. The dreaded "click"/voice coil bottoming occurs rarely, but I want to play the occasional Ginger Baker solo at live levels rather than just below.
Tapping on the dust cap of six different samples of this driver (six identical monitors), the suspect driver resonates at much higher frequency than the other five. One of six wood inserts stripped, preventing proper fastener torque. I'll check if this causes a leak leading to the click, but that's doubtful.
Maybe 20 years ago I read about a DIY potential fix (other than re-cone) for bogus mid bass. The fix might have applied to symptom such as mine, but I can't remember the fix. If anyone knows or thinks they know, please post.
Dynaudio re-cones 17WLQ but it's costly.
