[kazuma1111]

But i don't know time for this method ?

 

[r08zy]

But i don't know time for this method ?

I guess that's the best way, just allow them to stretch for a while. I know it's a fairly common complaint with Sennheiser that they clamp a little too firmly

 

[NA Blur]

Yeah, that or use a full-sized tissue box. That’s how I’ve always done it. Take about 4 days to a week.

 

[goodleechanghwa]

i agree that that's the best way

 

[kazuma1111]

Yeah, that or use a full-sized tissue box. That’s how I’ve always done it. Take about 4 days to a week.

Like this

 

[GREQ]

It might also be faster to use a hair-dryer or a heat-gun (on a low setting) to warm up the parts you want to stretch out.
Just heat up the parts that need stretching while its being stretched out over the box/container and allow it to slowly cool down.
This can be repeated a number of times.
I would avoid heating up the pleather cushion parts, I don't know how they would react to heat.

I've had success using this method to both reduce AND increase clamping force in plastic headbands.
It's still a fairly slow process and it really depends on the plastic, since some are thermoplastics and some are thermosetting plastics.
There's no way of knowing which one it is without contacting Sennheiser and even then, they might not tell you.

 

[ProtegeManiac]

But i don't know time for this method ?

Just note that you're also wearing out the pads, you just have no choice when the whole headband is plastic instead of a metal that you can bend in the other direction without breaking and thus can be done by hand quickly (eg HD580 and similar frame).

 

[NA Blur]

Like this

Yup, works great!