Most USB External Soundcards do not have a unique serial number encoded into the hardware. Windows can identify the brand and model but that is about it.
When you plug a USB soundcard into a USB port for the first time, Windows will install the device (via plug and play) and assign it a System Name (ex. "Generic USB Audio Device"). If you have several of the same USB soundcards, the Windows System Name will have a number added (see Listing 1 example). Actual naming convention for System Name differs by Windows OS version. And each soundcard will have a different Id derived from the name.
Listing 1. Identical USB external soundcards plugged into different ports.USB Port 1: Speakers (Generic USB Audio Dev, Id=886462652073781555 USB Port 2: Speakers (2- Generic USB Audio , Id=937430947834167215 USB Port 3: Speakers (3- Generic USB Audio , Id=921134518248621617
Always review your Output Groups after adding, removing or moving USB devices to different USB ports since Device Ids can change. Make sure the sound is being directed where you want it to go. Go to Tools > Outputs/Devices > View Output Groups and Devices and review all the devices configuration. When you verify it is all working properly, save a copy of the configuration to a text file for future reference.
Sound Quality Tip: For best quality sound on these adapters, try these settings. Not all soundcards may have these options.