Sennheiser HE60 investigation

[chinsettawong]

A pair of HE60 was given to me by a Thai friend. The phones must have been in storage for a long time as the vinyl on the ear pads come flaky off. So, I have to disassemble and clean the interior. Taking this opportunity, I take a few pictures.

The diaphragm to stator distance is around 0.5 mm. There is nothing special on the stator surface.

Wachara C.

[HeadphoneAddict]

You friend just gave them to you, to keep for free? Did they work when you got them, and what did you think of the sound? I've turned down offers for as much as $2500 for mine. When I first got mine there was a channel imbalance and I spent $500 having new drivers, o-rings and pads installed. The bass improved a bit after the new o-rings, and they're one of my favorite headphones, although a little more bass impact would be nice. Bass presence and extension however is good. I've considered turning my old drivers and spare pads into another HE-60, since the channel imbalance would improve with 3-4 hours of warm up.

[spritzer]

I highly recommend you add plastic sheets on either side of the HE60 drivers to keep the dust out. While no 'stat driver likes dust the HE60 can go a bit nuts...

[HeadphoneAddict]

Do the HE-60 drivers come standard with decent dust guards? I wonder of my old boxed up drivers are protected.

[chinsettawong]

Yes, my friend has given them to me for free. They also come with the Hev70 which, sadly, isn't working. I'll try to fix it later. Well, he isn't a DIYer and didn't have any other amp to try on and he thought that the amp and the headphones were all broken. He actually wanted me to take them apart to study the inside.

The drivers come with a protective plastic sheet on the side facing the ear. The other side is protected using some kinds of very fine cloth - maybe silkscreen cloth. They did a good job protecting the dust. When I opened up the drivers, they were very clean.

Talking about the sound, they sure sound pretty good to my ears. The bass impact isn't as good as Stax 407, but it's not too far off.

Frankly speaking, I feel that my headphones sound very similar to HE60 with a bit better bass.

By the way, Stax 407 is more sensitive than HE 60. The difference in spacer thickness of 0.15 mm sure makes a lot of difference.

Wachara C.

[spritzer]

The older Stax Lambdas also have woven dust shields on the back (which is what Sennheiser copied) but these were only effective back when there was a damping layer to seal out the dust. The Lambda Sigs were badly affected by this. The LNS (and all later models) feature PVC sheets on both sides of the drivers.

[arnaud]

Hi Wachara,

I tried to PM you at HF for some basic info on Stax electrodes but maybe you don't check there so often.

I am after some ball park values to help with a simulation of acoustic performance of the sr009. The things I am looking for in regards to Stax headphones:

• Typical tensioning on Stax drivers
  
• Typical first resonance frequency
  
• Typical stator diaphragm spacing
  
• Typical polarization potential of the membrane (I guess it's affect by the coating?)
  
  Any info you can share would be much appreciated!
  
  
  cheers,
  arnaud
  • 
    

Edited September 30, 2011 by arnaud

[chinsettawong]

Hi Wachara,

I tried to PM you at HF for some basic info on Stax electrodes but maybe you don't check there so often.

I am after some ball park values to help with a simulation of acoustic performance of the sr009. The things I am looking for in regards to Stax headphones:

• Typical tensioning on Stax drivers
  
• Typical first resonance frequency
  
• Typical stator diaphragm spacing
  
• Typical polarization potential of the membrane (I guess it's affect by the coating?)
  
  Any info you can share would be much appreciated!
  
  
  
  cheers,
  arnaud
  • 
    

  Hi arnaud,

  I'm very sorry. I haven't been checking that web site very often.

  Frankly speaking, I do not have concrete answers to all your questions. I'm am not an engineer, and I'm only doing this for fun. I can only give you some guesses.

  1. The diaphragm tension of Stax SR507 isn't that high. It's a lot lower than I thought. I would say the tension in terms of weight is around 1.5 kilogram.

  2. I have no idea about the first resonance frequency.

  3. The stator to diaphragm spacing of SR507 is around 0.35 mm. I have listened to SR009 once, and I feel that it's as efficient as SR507. I would say that the stator to diaphragm spacing of SR009 is also around 0.35-0.45 mm.

  4. I'm not sure what you mean by polarizing potential. But if you talk about coating, you want a coating that is giving very high resistance. The resistance is the range of 10 - 100 Mega ohm is good.

  The older Stax Lambdas also have woven dust shields on the back (which is what Sennheiser copied) but these were only effective back when there was a damping layer to seal out the dust. The Lambda Sigs were badly affected by this. The LNS (and all later models) feature PVC sheets on both sides of the drivers.

  Hi Spritzer,

  The diaphragm side that is facing the ear is the only side that is being energized, and if any dust goes in between, it will cause unwanted noise. It is therefore very crucial to have a good protection. However the back side of the driver isn't that critical. I don't put any protection layer on the back side of my drivers, and I actually like it better that way.

  Wachara C.