[DomieMic65]

  Looks like I'll be returning my alu then if it's not too late.
It's a shame cos the alu do strong thicker than the thinner sounding hd25. across the board. . 

the cups are not supposed to be TOO tightly attached to the headband...
as you describe it the problem (if any) sounds to be more on the 25s than on the Alus

 

[Fungus]

Maybe you're right cos I never remember my previous 4 pair of hd25 and 1 x amperior being so tight despite purchased used. To give some perspective, if I try to pull on cups down even with both hands, I always end up jerking them to the very end of the rail. Not very efficient 

How tight is your alu? 

 

[DomieMic65]

 
How tight is your alu? 

It is normal tight!
I can move it up or down quite easily, meaning that it doesn't seem  loose or anything else
When wearing them on it is a little bit more difficult but I try to adjust not while wearing them on mostly...

 

[Fungus]

  It is normal tight!
I can move it up or down quite easily, meaning that it doesn't seem  loose or anything else
When wearing them on it is a little bit more difficult but I try to adjust not while wearing them on mostly...

my alu are normal tight meaning that it can be adjusted while on my head quite easily but not the point where it will slide down with out assistant. 
I don't know if the clamping force on the hd25 is higher because of the different earpads. 

 

[WraithApe]

I think this may be a common problem with the Alus, because the slider on one side was way too loose on the pair I bought - it would move up and down at the barest of touches, and so kept slipping - very annoying. I had to return it to the store and have it sent back to Sennheiser to fix.

 

[DomieMic65]

  I think this may be a common problem with the Alus, because the slider on one side was way too loose on the pair I bought - it would move up and down at the barest of touches, and so kept slipping - very annoying. I had to return it to the store and have it sent back to Sennheiser 

mine don't have this problem

 

[WraithApe]

  mine don't have this problem

 
Good for you 

 

[moriez]

Sounds like a random thing not limited to one type of HD25. I bet Sennheiser knows about this particular problem very well.
 
Maybe @jfunk who's seen hundreds of HD25 can tell us more.

 

[jfunk]

  Sounds like a random thing not limited to one type of HD25. I bet Sennheiser knows about this particular problem very well.
 
Maybe @jfunk who's seen hundreds of HD25 can tell us more.

It is not that common but yes I have seen a few pairs with that problem - there is a plastic spring built into the driver that presses on the ridges on the arm to stop the cup from easily sliding up and down. If that has a crack in it then the earcup slides up and down too easily and it can be very annoying. Inside warranty I would expect sennheiser would sort them out but if you are outside warranty then there is a ghetto fix -
 
Depending which ear it is ... Remove the cable clamp / name plate
Underneath you will see the offending bit of plastic - the is a strip down the middle, in-between the screw holes with a dip in the centre. ( some newer ones have a sticker over it which you will have to remove )
If you cut a small section out of a cocktail stick, roughly 5mm, it will rest perfectly in that dip and support the spring from behind
Then if it is the cable clamp side just screw it back together and the cable clamp will hold it in place or on the name late side you may need a little dab of glue to hold the name plate tightly in place. You may not so try it without glue first
 
As it is part of the driver, it is just as likely to happen on any HD25 but as I said... I have only had 4 or 5 with that issue out of may thousands that have gone through my hands.

 

[Fungus]

 
It is not that common but yes I have seen a few pairs with that problem - there is a plastic spring built into the driver that presses on the ridges on the arm to stop the cup from easily sliding up and down. If that has a crack in it then the earcup slides up and down too easily and it can be very annoying. Inside warranty I would expect sennheiser would sort them out but if you are outside warranty then there is a ghetto fix -
 
Depending which ear it is ... Remove the cable clamp / name plate
Underneath you will see the offending bit of plastic - the is a strip down the middle, in-between the screw holes with a dip in the centre. ( some newer ones have a sticker over it which you will have to remove )
If you cut a small section out of a cocktail stick, roughly 5mm, it will rest perfectly in that dip and support the spring from behind
Then if it is the cable clamp side just screw it back together and the cable clamp will hold it in place or on the name late side you may need a little dab of glue to hold the name plate tightly in place. You may not so try it without glue first
 
As it is part of the driver, it is just as likely to happen on any HD25 but as I said... I have only had 4 or 5 with that issue out of may thousands that have gone through my hands.

So would you consider a brand new pair that is adjustable with one hand by squeezing the cups downwards be considered normal or faulty like the 4-5 your identified? I can still hear the clicking sound for ever small adjustment made however it's nowhere near as tight as the hd25 that I also have with me.  

 

[jfunk]

  So would you consider a brand new pair that is adjustable with one hand by squeezing the cups downwards be considered normal or faulty like the 4-5 your identified? I can still hear the clicking sound for ever small adjustment made however it's nowhere near as tight as the hd25 that I also have with me.  

There are variations in tightness and at least two different mouldings for the arms - some are very tight and clicky some normal but if you can hold it by the headband with the earcups at the top and give it a little shake ( not too hard ), if an earcup slides down then it is abnormally loose and I would contact the seller, especially if it is just one ear. If they stay where they are then they are doing the job and I would not worry about it.

 

[Fungus]

I'm amazed by the improvements by replacing just the plastic cups to aluminium. The low fequencies and sub bass on the alu is so much cleaner sounding with so much more extension that I might end of taking the hd25 back to the store despite originally intending to keep the hd25 to use on the go due to the better grip, lightness and more discreet looks. To be honest I initially thought the differences would be subtle that if I purchased the alu and hd25 to compare them side by side, I would be sure to choice the hd25 and refund the alu and use the difference in cost to save on something else but unfortunately I'm now convinced it's not the case cos it's really night and day and I can swear it's not placebo. 

 

[jfunk]

   it's really night and day and I can swear it's not placebo. 

 
Yes - the HD25 are really nice and light but that acts against them with the low end - a lot of the bass energy goes into vibrating the earcup rather than making sound - a little mass in the right place helps a lot which is why the heavier more ridged alu earcups improve the bass. Check out the vid below for a perfect example. skip to 3:16 to see a standard pair of HD25 and the difference a bit of solid mass makes to the waveform

 

[DomieMic65]

Guys are there any after market pads with beter foam in them like memory foam or something?
I see that the pads on my Alu are very much squized after some time ... I am wondering how the comfort and the sound will be effected with some somehow more "hi-tech" pads!
 
From the original pads witch do you prefer?
velour or the others (don't know how they are called  )

 

[WraithApe]

@DomieMic65 Dunno whether you've seen them before, but there was some discussion of these 'Yaxi' pads over on the Amperior thread: http://www.head-fi.org/t/612632/sennheiser-amperior-impressions-thread/870 - never tried 'em myself though.