8-channel ESI Gigaport HD+ / weird USB port issue

soundscrapers's icon

I am running Max on a mid-2014 MacBook Pro with an ESI Gigaport HD+ 8-channel audio interface plugged into the High Speed USB 3.0 port. I have noticed something odd. When the Gigaport is plugged into the MacBook's right USB outlet, channels 1 & 2 have something like a -20dB drop in the sound level. Channels 3 through 8 are fully functional. When it's plugged into the left outlet, however, everything works perfectly.

I even changed the Mac's system preferences to output through the Gigaport, and that audio is at full volume when played from other applications. Only Max seemed to have the drop in channels 1 and 2.

Anyone have an idea what's going on here?