Flabby sound could be
a symptom of a blown driver.
Have a look at this thread
; thy guy overdid it with artificial "burn-in" and fried his new headphones in the process.
Generally, the drivers of any loudspeaker are mechanical devices, and there is no reason to believe they will last forever. Speakers age, and eventually they wear out. This may take decades, though, under normal conditions. Once you have accepted that, it would be odd to assume that the ageing process will not be reflected in the sound in any way.
My room speakers came with a bottle of silicon-based fluid and the recommendation to apply on an annual basis a small amount to the rubber parts surrounding the membranes. This may help maintain their elasticity for much longer.
Diaphragms of headphone drivers are possibly too small or too fragile (and not always easy to access) to do this, but who knows, maybe it can be done.
My theory is that all moving parts, such as drivers, are subject to ageing. There is a short break-in process at the beginning, then a long period of useful life (unless you are Shang-Ti Chen), and a period of breakdown before "death" of the driver.
Originally Posted by tmarshl
We have all learned a lot about the time necessary to "break in" headphones, sometimes as much as a hundred hours or more, until the sound gets really perfect. Then there is a period of terrific sound.
But after a while, don't the diaphrams get a bit loose and that terrific sound gets a bit flabby? Has anyone experienced this phenomonon?
What to do? I guess one just must replace the drivers and start a new break-in cycle?