Audio Precision ASIO Driver Bypasses Windows Audio for Direct Testing of Pro Audio PC Interfaces

Any USB, Firewire or PCI  audio device with an ASIO driver can now be tested by APx audio analyzer, bypassing the resampling, gain and latency of the Windows audio system.

133rd AES CONVENTION, MOSCONE CENTER, SAN FRANCISCO, October 27, 2012: Audio Precision, the recognized standard in audio test, today demonstrated its new ASIO driver, used to bypass Windows audio when testing pro audio PC interfaces connected by USB, Firewire or PCI.

ASIO is a PC audio driver technology developed by Steinberg Media Technologies GmbH (and since adopted across the pro-audio industry) that allows audio software to communicate directly with connected audio hardware with extremely low latency, high channel count and bit-transparent transfer of data.

In APx500 v3.1, connected audio interfaces with installed ASIO drivers appear within the APx software as one of APx’s I/O options, with support for up to 16 bidirectional channels. All measurements and test sequences in APx may be used via the ASIO interface, allowing for complete characterization of the connected audio device.

A typical configuration might be APx’s low noise analog output to a professional analog-to-digital-converter (ADC), which streams converted digital audio to the PC via USB. Within the APx software, the ADC will appear as a selectable audio input. To test the device, APx would send an analog signal out to the device’s analog input and compare that output to the resulting audio stream within the PC.

ASIO and PC Audio
ASIO is widely used on Windows-based PCs for professional recording and production because audio interfaces that rely on the native Windows drivers typically experience latency and unknown gain, distortion and resampling. Using an ASIO driver in a test & measurement situation ensures that it is the performance of the device under test being measured, not the unknown effects of the Windows operating system interfering with the measurements.

Price and availability
ASIO is standard for APx525 and APx585 families as part of the APx500 v3.1 update available now for download at The APx 515 production test analyzer supports any two channels of ASIO at one time and requires the ASIO software option (SW-ASIO, $750) or the APx515 software bundle 2 (SWB-2, $1500). Prices quoted are valid in the US and may vary in other countries.

About Audio Precision
Audio Precision is the recognized standard in audio test. Since 1984, AP has offered high performance audio analyzer instruments and applications to help engineers worldwide design and manufacture all types of consumer, professional and industrial audio products. For more information, visit