ASIO Devices

About Audio Interface Drivers

Hardware audio interfaces (such as Focusrite Scarlett, M-Audio M-Track and PreSonus AudioBox) require drivers to enable communication between the device and the computer to which they are connected. Drivers are small software programs that typically have to be specifically installed on the computer before the device can be used (some devices however use ‘default’ operating system drivers).

Typically, audio interfaces come with drivers for Mac macOS and Windows.

For macOS, drivers are written for ‘Core Audio’, which is the native audio infrastructure in macOS.

For Windows, drivers are typically written for WDM (Windows Driver Model) and/or ASIO (Audio Stream Input/Output). WDM is the standard model for most varieties of Windows drivers, and provides a controlled, traditional route into and out of the computer hardware. ASIO is a more ‘direct’ audio driver protocol that bypasses some of the Windows software layers, enabling lower latencies. You could think of WDM as walking in through the main entrance and taking the elevator to your floor, and ASIO as abseiling straight in through the window, from a helicopter.

Prior to version 1.1, Dante Via supported only WDM drivers for Windows. This meant that audio interfaces appeared in Dante Via in their WDM guises. Some audio interfaces, for example, might support 8 or 16 hardware channels of audio, but the WDM driver was only written for 2 channels – so the device would appear in Dante Via as a 2-channel device, and you could only route 2 channels of audio through it using WDM.

From version 1.1, Dante Via also supports ASIO drivers. This means that some ASIO-compatible devices will now present more channels to Dante Via, and you can also enjoy the lower latencies provided by ASIO drivers, where they are available.

ASIO devices are indicated by this icon:

Note:  The increased channel support for audio interfaces can increase the likelihood of resource limit problems (see Insufficient Resources).

Audio Interfaces with Both Types of Driver

Some Windows drivers for audio interfaces will install a WDM and an ASIO driver. The WDM driver will usually be used by ‘consumer-level’ audio-enabled software (such as Skype), and the ASIO driver will usually be used by professional audio software (such as Nuendo).

Dante Via can detect both drivers – the 'Show ASIO compatible audio devices' option in the general preferences determines which driver types are displayed in the user interface. When the option is selected, audio interfaces with WDM and ASIO drivers will appear as two separate sources, and two separate destinations (assuming the interface supports both input and output).

The actual device names may vary. For example, a Focusrite Scarlett 2i2 USB interface will appear in Audio Sources > Local Audio Devices as ‘Line In Scarlett 2i2 USB’, and in Audio Sources > Local ASIO Audio Devices as ‘Focusrite USB 2.0 Audio Driver’. In Audio Destinations > Local Audio Devices it will appear as ‘Line Out Scarlett 2i2 USB’, and in Audio Destinations > Local ASIO Audio Devices as ‘Focusrite USB 2.0 Audio Driver’.

Important:  Some interfaces do not support use of the WDM and ASIO driver simultaneously, and may even become unstable if one driver is initialized while the other is active. For these interfaces, it is recommended that the active driver is fully ‘disengaged’, by removing all audio subscriptions to and from the active driver, before attempting to route audio using the other driver. It may also be necessary to power-cycle the hardware device. Also, some ASIO drivers do not report full and/or accurate information to Windows, and as such may require that the PC is rebooted if the driver stops responding.