USB question

Hi,

I have a 2013 iMac 27 inch. Its running macOS 10.15.4.

I also have an Audioengine D1 DAC, that’s connected via usb.

Its my understanding that my iMac’s usb ports are 4 usb 3.0 ports.

I recently was playing around with the audio midi setup and was trying to increase the format to 88khz.

I sometimes hear a bit of popping/crackling sound. I believe at the higher sampling rates uses more bandwidth.

So i looked at my system information and noticed that under ‘USB’ the D1 connects to the USB 2.0 hub in system info and always has a max speed of 12 mb/s

That seems slow to me, not sure if that is a limit of the D1, I’ve tried plugging it in to different usb ports with the same result.

Is there something i can do to increase this?