[leeperry]

Why does it matter?

 
well, because it's the science forum? you've become a speakers guy now, I presume?
 
here's a thread full of drivers sex pictures: http://www.head-fi.org/forum/thread/202122/the-headphone-driver-pics-thread/15#post_2519360

Stax SR-202 Driver
Specs:
Transducer: Electrostatic
Biasing Voltage: 580Volts

OMG, that's a lot

 

[jennyb]

Just because Wifi was installed in your elementary school does not mean it is safe.  Have you personally interviewed each and every child to find out if they have had any "issues" with the wifi.  Harder time concentrating maybe? Constant headaches at school that seem to disappear when not in the wifi environment? - - then you don't really know.  Just because nobody came home without a leg because it fell off from wifi, or when the switch was flipped everyone in the vicinity didn't get a nosebleed,  doesn't mean there aren't subtle changes.  Do some research, there are many studies showing the changes of blood cells when in a wifi environment.  I worked in a hospital for years with no problem.....OH, but then again hospitals have filters built into the system...  Until there is NO reaction to the blood cells with wifi, then I would say it is safe, but that just isn't the case.  I value my son's life much more than the technology of wifi.

 

[ddrddrddrddr]

Wifi environment? If there's such thing as a headache due to wifi, they would be would be under constant suffering at my university. EVERY building here have wifi. It really won't matter how much you value your life's life, if he's going to have a higher education, he will be surrounded by it. Technology is a fact of life. Besides, "a person absorbs less radiation from sitting in a wi-fi hotspot for a year, says the HPA, than from a 20-minute cell phone call."
source: http://www.wired.com/wiredscience/2007/05/nothing_to_fear/

 

[Head Injury]

Quote:

Harder time concentrating maybe?

Yeah. They keep posting on Facebook instead of doing their work.

 

[leeperry]

humm, I've been listening to an HFI-780 for a little while now...very impressed after some EQ to kill resonances(it's got a nasty spike in the mids that I'm trying to locate)...anyway, I hated the S-Logic on the Pro750 but the S-Logic+ in the 780 is quite something!
 
It's pretty clear that they know a thing or two about drivers engineering...wide 3D SS w/o being overly reverbed/wet. And yes, it's got that ULE shielding thingie as well. It's clearly audible that the sound pressure is lower for the same loudness perception, too bad the mids are mushy as hell.

 

[leeperry]

mu-shielding yada yada: http://www.head-fi.org/forum/thread/452404/just-listened-to-some-fostex-t50rps-today-wow/90#post_6882020
 

 
that's a t50rp driver, I should have one next week.

 

[Phryq]

Is that a picture of shielding on the headphones? How is that possible?

Anyone got measurements comparing magnetic / dynamic headphones for EMFs?

 

[bigshot]

What a nice thread to resurrect after almost ten years. Thanks for the memories!

 

[Phryq]

Would it have been better to start a new thread? What's the etiquette on this board?

 

[castleofargh]

Would it have been better to start a new thread? What's the etiquette on this board?

we hardly even stay on topic so you wishing to discuss an old topic is very fine.

as for shielding, you can affect a magnetic field with a metal, be it a plate or mesh(look up Faraday cage for specifics).

 

[bigshot]

I just meant to say that you aren't likely to get replies to your questions when the thread is a decade old. You might try PMing leeperry. He is still active on HeadFi. His avatar indicates he's gotten on in years though!

 

[Phryq]

Ok, ya, I did PM someone else, but I'll try him too.

Just measured my own Planar Magnetic cans, and they had 0 magnetic fields, but some Radio Frequencies, and high electric fields.

The RFs must be from the cable, so I imagine a ferrite bead would fix that easily.

But putting something between the drivers and my ears, like an electrical-field blocking fabric... I think would affect sound quality? And I think it'd have to be grounded to work.

 

[leeperry]

you can always shield your cable to begin with coz atm it's basically a RF antenna, dual twisted pairs as a starter and further shielding if required

"those who speak don't know and those who know don't speak", last pages of this thread might shed some lights though so please let us know what you find out

 

[Phryq]

Ya, I was thinking of a Ferrite Bead to get rid of the RFs, but am more worried about the ELFs...

And I was also thinking of buying a new pair of either planar magnetics or dynamics... but maybe I have to switch to speakers.

I read the last few pages of this thread btw, very helpful.

 

[Phryq]

So I realized, the majority of electric-fields are not coming from the headphones, but from the wall-power.

When my laptop's not plugged in, the headphone ELFs are relatively low, but when I plug the laptop in, the plug, laptop, and any device plugged into the latop measures 1000 V/m...

So is this a problem with my grounding? I don't think a ferrite bead will stop this?