[charmerci]

I understand that when you push the speakers to the limit and the woofers go in and out towards their extremes, the bonds are more likely breakdown as well as reduce the lifetime of the surrounds. Has anyone done any studies on this? Does it make a huge or small difference in how long woofers last?

[*Scotty*]

It is very doubtful that any one has bothered to do this sort of extended wear test. The bigger problem that is encountered when the woofer nears the mechanical limits of excursion is that it often exceeds them and its voice-coil hits the back plate of of the pole piece and the voice-coil is damaged. If the driver is properly designed the spider will control the drivers excursion and the surround will be sized such that it is large enough that it is not placed under stress even if the voice coil is damaged by by hitting the backplate due to over excursion.
 Unfortunately you can't assume that a driver has been designed this way.
If you are concerned about this, understand that the amount excursion the woofer undergoes is a function of the amount of bass frequencies the woofer sees. You might consider removing some of the bass by using a sub-woofer to handle frequencies below 100Hz.
Scotty

[Letitroll98]

Also note that if you're driving your woofers to this extreme they are low quality drivers or you are playing your music way, way too loud.  Back in the day we used to bang the voice coils against their stops regularly, with a loud click or pop, but they were much more compliant suspensions then and the quality of parts generally much lower than today.  I haven't bumped a voice coil against its stop with anything made since the late 80's.

More to the OP's question, even medium quality drivers with butyl rubber or neoprene surrounds should last decades in normal use, foam of course deteriorates rapidly.  I'd have to believe the larger driver manufacturers have done destructive testing on their products, but are unlikely to publish this data.  Therefore you'll likely need to replace the capacitors in the crossover long before the woofer driver.   

[charmerci]

Well, the speakers in question are my Dennis Murphy Philharmonitor .5's with a Seas 7" mid-woofer so quality is not a problem. I was just curious because I do monitor (hee, hee) the woofers when I turn them up so they're not going in and out too much. When I turn them up on some songs, they seem to get nice and loud but then a song will come up off of Elvis Costello's Momofuku and BOOM those woofers really start pumping in and out and I turn it down.

And yes, I do remember when younger occasionally having those voice coils popping against the stops.

It was more a question of curiosity. May get a subwoofer for it now that you mention it, Scotty. Though these go down to the mid-40's so they're not too bad as they are.

Thanks for the responses.

[charmerci]

OK. You guys did it.

I went a bought a used Polk PSW10" subwoofer on amazon for $100. Now I can play music louder with real bass. And yes, the 7" mid-woofers go in and out far less. Definitely a different system now!

They're really great for the price. They're a bit boomy but for the price - who's complaining? (I have the output down to the minimum.) If you want a cheap subwoofer, I'd recommend one. (They're 15x14x16)

Addition - I have  just a standard receiver so the speaker cable goes through the subwoofer/high pass filter to my speakers with a ribbon tweeter. It seems to me that that the high frequencies are a bit harsher than before. But I changed it - using the pre-outs to the subwoofer input and using the speaker through the normal receiver speaker outputs and the Phils sound good again. When the bass is too much, I just turn down the bass on my receiver.