EHS36 with Sennheiser DW Office

[BrettB]

I finally got an EHS36 with the special "Y" cable needed for the Sennheiser DW Office wireless headset. I've connected the cables as shown in the EHS36 manual. However, it doesn't seem to be working right. I can't hear anything through the Sennheiser headset, but the person on the other end can hear from the mic on the headset. Also, I haven't been able to get the headset button to answer or hangup the SIP-T28P.

I've upgraded the Sennheiser firmware to the latest (v. 111). And I've got version 2.61.0.80 on the T28. Do I have to set anything special in the config for the T28, or does it just detect the EHS36 connection automatically?

And can you confirm what the proper settings for the Sennheiser are when connected to the EHS36? I tried the setting for DHSG (switch 1 down, and 2 up) and the setting for MSH (switch 1 up and switch 2 down).