Hi, it is Peter from HiFiMAN. All good follow-up questions this morning and Fang has asked me to reply.
Autoexec- that is the driver you want.
Vegards, have a look at autoexec's pic. Also Jerg has posted excellent images elsewhere in this thread. The bad support is a distinct yellow color.
Matt, plan is to stick with the so-called Rev 2 version. It was never HiFiMAN's intention to create different versions. Really the only significant change was from the first model introduced in January to the redesigned driver that appeared in March.That was done for durability and in the process the new version sounded better! Response to that version of HE-400 has been so good that it wouldn't make sense to keep changing it.
The mod with the yellow plastic support was done to strengthen support for the driver. It was not intended to change the sound but unfortunately it did.
Hope that answers the latest round of questions. By tomorrow, you will start getting responses from HiFiMAN customer service.
Peter