Hello, everyone. My name is John Walker, I live in Portland, Dorset in the United Kingdom, and have owned a pair of Martin Logan Quest Z speakers since 1999. I would appreciate advice on keeping these wonderful speakers in use, and in tip-top condition.
My power amps are protection-free, and a problem has begun to develop with the amp that drives one of the panels. I think I've found the main problem elsewhere in the system (an intermittent connection in a cable), but in taking the system apart, I've realised that the speakers are not performing as brilliantly as they did when new(er). Sensitivity overall, and treble brilliance have definitely decayed as evidenced when I plugged in a pair of cheap bookshelf speakers.
Portland is famous for stone, so it's a very dusty environment. I've already taken the panels off and carefully run the shower over them as recommended by at least one post. Are there any resources/members that would help me identify common problems with the crossover/HT unit? All the caps and other passives look like new, and I cannot see any dry joints. DC resistance between the speaker terminals was 8.3/8.4 ohm (bass unit) and 4 kOhm on the HF terminals with the panel disconnected. Resistance between diaphragm and each stator measured open circuit on my meter.
Any advice or tips on how to proceed would be very welcome.