Sonifex Pty Ltd T/A Innes Corporation
12/6 Leighton Pl
Hornsby, NSW 2077, Australia
Phone: +61 2 9987 0499
Fax: +61 2 9987 0599
E-mail:
sales@innescorp.com.au
Website: http://www.innescorp.com.au
8
Auricon 2.2+ Manual
use the Core Audio APIs, which include the DeviceTopology API and the EndpointVolume API
(which includes the IAudioEndpointVolume and IAudioMeterInformation interfaces). These are
documented in the Windows 7 SDK which is available from Microsoft, however note that these
APIs don’t work with earlier versions of Windows.
Alternatively, applications can be given access to the hardware mixer controls through the mixer
API by right-clicking on the application’s icon, selecting Properties, clicking on the Compatibility
tab and selecting
Run this program in compatibility mode for Windows XP Service Pack 2
. Be
aware, though, that in this compatibility mode, the Auricon 2.2+ card is represented by a single
mixer device with destination lines for each of the individual inputs and outputs, which is slightly
different to its behaviour under Windows XP where each input/output pair had its own mixer
device. How this will work with any particular application that uses the mixer API can only be
determined by experimentation.
Audio Engine
The Windows audio engine runs at a fixed sampling rate and bit depth. By default, the Auricon
2.2+ driver sets this to 48kHz 24-bit for all the inputs and outputs. The Windows sampling rate
converter is used whenever a different sampling rate or bit depth is requested by applications.
The engine sampling rate and bit depth for each endpoint can be changed if required by
selecting the endpoint, clicking on Properties, and then clicking on the Advanced tab.
If your applications will be playing or recording at rates higher than 48kHz, you will need to set
the audio engine to 96kHz otherwise Windows will down-sample to 48kHz.
Windows Vista / 7 / 8 Mono Recording Bug
Windows Vista / 7 / 8 has a bug which causes mono recording streams to capture only the left
channel of the source, rather than mixing the left and right as previous versions did. As a
workaround until this is fixed, the latest driver provides a
Mono Mix
recording endpoint for each
of the card’s inputs. By default these are disabled, but can be individually enabled as follows.
Right-click on the loudspeaker symbol in the bottom right hand corner of the screen and select
Recording Devices
. Right-click on any of the sources and check
Show Disabled Devices
,
which should then reveal two additional sources called
Input 1 Mono Mix
and
Input 2 Mono
Mix
. To enable these, right-click on them and select
Enable
. Note that, after enabling, it will still
show as
currently unavailable
as these endpoints are multiplexed with the normal stereo inputs
and are only activated when opened by a recording application. Also be aware that, for the
same reason, the
stereo
and
mono mix
endpoints for the same source can’t be used
simultaneously.
The
Mono Mix
endpoints should be used for communications applications such as Skype which
open a mono capture stream.
