Is there any way to improve the performance of the USB port/device passthrough without having so passthrough the entire controller? I have an USB audio interface, using the usb passthrough I get crackling noise whenever sound (specially louder ones) is played. By passing through the entire controller of the motherboard to the VM using PCIe passthrough the crackling noise dissappears, however the problem is that my motherboard only has 2 controllers (one being the front I/O panel) so if I passthrough the entire controller to one VM I will loose the ability to pass a usb device/port to another VM. What I am looking is a way to make the usb port(s) passthrough more efficiently.