First of all, thanks for your contribution.   Unfortunately, the number of data is too low at the moment. I hope it will grow in the future to build some reliable graph.

  Thanks, I had the same problem last week. Before coming blu, the purple light took longer (even to 20 minutes) and some times switched from blu to purple during listenining. Then I put it sounding with a cheap headphone the whole weekend 4-6 hours working, 1 hour pause. Now is working like...

what to fix on the EF6?

Some people is asking me things such this:   "Ok, I would like to write a report card but I do not own Dt880 or HD600, how can I do?"   Referring to this "rule":   - For reference we think about HD600 and DT880 headphones, they can have an average about 6.5 to 7.5.   It is not mandatory...

I consider 10 to be the best, not necessary perfection.   Till now I've haven't received a lot of report-cards containing a lot of 10 inside.   Also the low judgments are rare. Not a great amount of 4 and 5.

We are trying to collect data to build Headphone report (report card) If you want, please help with your contribute:   http://www.head-fi.org/t/787898/headphones-report-card-lets-judge-them   Judge the headphones  !!!  

IMHO after 3 minutes, and may be less,  is always based on memory   I think a good use of common sense is needed, I think I know pretty well some of the headphone I do not own anymore. So I will evaluate them. We haven't put any rule about this.

subbed, really intrested in this HP for the office.

Yes. HE500 needs a good and powerful amp to sound as good as it can.

for the moment we have a good number of evaluations / report cards of Sennheiser, HiFiMan, STAX, AKG-  Especially HD800, HE500, SR507, K701   Not so good for Beyerdynamic, Audeze, Grado, Shure and so on.

  The music genre is important. As well as gear used, cables type of pads, some headphones have velour/pleather options... but if we should put every variable it would result exhausting to do for every body. To many parameters.   About Music I thought to put put parameters  : classical, rock...

Separate, then summed and then divided by the number of reports.   At the end the single spreadsheet (anonymously) and the composed ones, will be available for free download. So everybody can see and use the data the way they want.

In the meanwhile...   Example of data-sheet that we are using:  

Mesurements by Innerfidelity   http://www.innerfidelity.com/images/HiFiMANHE1000.pdf   Not so perfect in THD

EF6 + HE1000...  YES! Good pair!