Driver lifespans?

[crackyflipside]

In drivers large and small, assuming that there is no mechanical break (like a disconnected VC, broken spider, broken surround, etc..), and that you just put lots and lots of listening hours on a driver. Over time, does the motor lose performance?

And are any losses in performance noticeable?

Edit: And can any of these changes over time permanently alter the T/S parameters?

[Kevin P]

As long as the driver remains mechanically sound, it should last "forever". Usually what wears out in drivers is the surround drying out and cracking (or "rotting" in the case of foam surrounds), or the cone itself drying out and cracking/ripping.

And even if these things happen, there are companies that can "recone" drivers.

[mmoeller]

Interesting question.

I would look at it from a materials point of view.

1. Magnet - permanent magnets well not degrade noticably over time. There are a couple of ways that these magnets will degrade. They get close to their "Curie" temperature, which is usually hot enough to melt everything else (80-250C for Neo) Or you could apply a magnetic field, mabey 10000 KA/m to demagnetize. Some very intense AC Electrical signals could degrade the magnet over time. Mabey a Nuke could do it? Neo magnets can have a lifespan on the order of 10,000 years.

2. Spider - in engineered properly, and not abused, it would maintain a hysteresis for a considerable amount of time. Taken past the metals elastic range could cause problems. The properties of the hysteresis would change, without fail changing performance.

3. Coil - Depending on the material used to wrap the coils around. Some type of breakdown of this material may take place. I'm not sure what the standard materials would be, paper?, laminated plastic?, aluminum? Some probablly live longer.

4. Cone - Again paper or other laminated structures always have the risk of delamination in unfavorable conditions.

5. Surround - ditto.

I don't think the motor would lose any magnetization over time, or any noticable amount in the next 100 years. But neglect and abuse could certainly cause some grief. IMHO.