Prof - Speakers have very few issues which I'll summarize here.
The cabinet is basically permanent, as long as you avoid furniture polish with silicone, which breaks down the finish. Also avoid sunlight as practical.
The drivers can last a long time - many decades. Thiel surrounds are natural rubber, the best of form. But direct sunlight degrades it. Keep the grilles on. The moving cone / dome /coil is connected via braided leads. They eventually fatigue and break. I hope to get and Rob does have the various lead braids. The usual cause of unabused driver failure is broken leads, which can be replaced. Voice coil burnout is caused by distortion or accident, which necessitates rebuilding. Avoid burnout.
Crossover parts, used within power limits are virtually permanent EXCEPT electrolytic capacitors, which have a life generally considered 15 to 50 years. Your 02s are near end of life. Thiel always used best of form electrolytic caps, and we have never heard of a single failure to date, but the bomb is ticking. They are replaceable with care with original or equivalent or upgrade to ERSE PulseX propylene for permanent solution.
The 2.7 has a large cap bank feeding the midrange to roll its low end out higher than the same driver in the 3.7. The 2.7 XOs were Lexington built, so highest quality caps were used. I would budget 40 years life from accumulated experience.
Side note is that much of my present upgrade development revolves around heat management, which will extend life greatly and reduce age-related value drift. Electrolytics become less effective with age which shifts XO crosspoints. If shifted downward, then additional power can heat the driver motor to failure. Your O2's port helps cooling.
Thiel's historical experience is that most Thiel customers who bought from first-rate dealers (use education) never had a single problem, short or long term. About 10% of the customers had near 99% of the problems. The great majority drove into distortion with under-powered amps. Our warranty covered, in fact, such abuse ONCE, with an explanation and warning. Next occurrence was not covered. Rob is educative and generous, but most failures are user created.
