Do you ever have to re-break-in speakers?


Odd question but I recently purchased a barely used pair of speakers. I'm sure he listened to them long enough to break them in but then he moved to another model and they sat for quite a while before I purchased them. I've listened to them for a few weeks now and I swear they sound better now. Do new-ish speakers stiffen up again if left unused for a long period of time? Or are my ears just getting used to them?
128x128ratboysr
Only if you replace a driver or crossover, as far as I know. What you probably experienced is the speaker cables and internal wiring just got re-acquainted.
I've listened to them for a few weeks now and I swear they sound better now.

Right. I'm sure they do.
Do new-ish speakers stiffen up again if left unused for a long period of time? Or are my ears just getting used to them?

No, and its not only speakers. Everything sounds better when its running a while. At least as far as I can tell. There's cycles everything goes through.

From new: expect massive rapid improvement the first few minutes to hours, followed by continual gradual improvement for anywhere from a few days to several months.

From on: expect noticeable rapid improvement for several minutes to a few hours as the component warms up after having been off a while.

From whatever: expect small slow gradual improvement from daytime into the late evening.

None of this is theoretical. Its all based on actual listening experience with a lot of gear over several decades. Exceptions are rare, to the point I can't think of any, but I leave open the possibility.

Its not stiffening up because it happens with things like cables with no moving parts, and even things like amps where the parts are fastened and cannot move even relative to each other. I warm up my system every night both by turning it on and by playing demagnetizing tracks but even so there is no way to warm up the cartridge other than by playing records. I've tried enough permutations to know the phono stage, motor, and even the cartridge each go through their own warmup cycles.

Congratulations, you are a listener. One would like to think all audiophiles are, but sadly this is not the case. So congratulations, and welcome to the club within the club.
OP, In my experience, yes.  I had the same situation as you where the previous owner hadn't used them in a while.  The bass was anemic when I first started playing them but, after 10-15 hours or so, they started to loosen up.  It's not hard to imagine that rubber surrounds need to be played to stay flexible.
If it's in the bass, then it's the drivers.

If the treble opens up, the caps.
Absolutely, I needed about 170-200 hours on my speakers before they owned up, even now, after sitting for months at a time, they need a bit of warm up, 
amps, preamp, CD player, speakers all need break in

 I have good ears, and I can heara huge difference after hours of warm up and low volume playing vs. a cold start and music.

bass deeper, better highs, more in your room guitar.

not a myth.