How do I run the Windows Vista Audio Fidelity Logo Tests?

The Windows Vista audio fidelity logo test results are required for all Windows Vista audio device and complete system logo submissions, even though passing test logs will not be required for system submissions until June 1, 2007.

To help in understanding these various levels of requirements, Optimal Sound has compiled a comprehensive table of audio fidelity requirements contained in AUDIO-0006, AUDIO-0025, SYSFUND-0118, and SYSFUND-0127, showing the fidelity requirements for Basic and Premium logos. Additionally, the Premium logo requirements have separate sections for desktop and laptop. The Premium laptop requirements are virtually identical the basic requirements, while the Premium desktop requirements take a step up from the basic requirements for most categories.

Click here to view Optimal Sound's audio fidelity requirements table based on WLP 3.07.

Microsoft has posted a policy page at http://www.microsoft.com/whdc/whql/audiofidelity.mspx which provides additional details on the requirements to run audio fidelity logo tests.

Audio fidelity test logs must be provided by using one of the following options:

Option 1 – In-House Testing
This approach allows OEM partners to complete the system submission test by using the Audio Precision System Two hardware without assistance from third parties. To do this, the OEM must purchase a dedicated AP System Two for each DTM test site equipped to run the audio fidelity tests, run the audio fidelity tests, and perform the logo submission using the audio fidelity test results.

Option 2 – Leveraged Resource Testing
OEM partners may instead choose to use the DTM to import audio fidelity test logs created by an outside resource, such as Optimal Sound. To do this, the OEM should import the logs from the outside resource, which may be a third-party test house, and ODM, an IHV or codec vendor, or any other test facility that has access to an Audio Precision System Two and the DTM

The imported log files must have identical audio 4-part PNPID and pin configuration as the final submission. This means that the test house must run the fidelity tests on exactly the same model and version of the motherboard that is being submitted for system logo.

Each system must be tested individually. Unlike for Windows XP, the fidelity tests must be run on each unique system model. There is no provision for running the tests on one model in a product family, and then applying the test results to all models in that family. This is a big difference from previous logo submission policies.

The following diagram shows the basic configuration for a DTM test system incorporating an Audio Precision System 2 test set. In addition to the domain controller and the DTM controller which are a part of every DTM setup and which each must run Windows Server 2003, an Audio Precision host system must be added. This system provides an interface between the Audio Precision and the DTM. Audio Precision software and drivers must be installed on this system, and the Audio Precision must be connected to the AP host system using Audio Precision's proprietary APIB interface, which is a parallel bus somewhat similar to IEEE-488 GPIB. The analog audio outputs of the system under test are routed to the inputs of the Audio Precision's analyzer block.

In addition to the standard DTM test procedures, additional manual configuration is necessary to open special ports through the firewall, and some DLLs must be copied from the DTM controller to the AP Host controller and registered with the AP host. The tests can be run from the DTM Studio application, or they can be run from the command line of the system under test.

There are currently four tests implemented in the DTM, but additional tests are expected to come on line by June 1, 2007 when passing audio fidelity test logs will be required for every system submission.

Output Level Test plays a digital full-scale signal and verifies that it meets the Full-Scale Output Voltage requirement in the Windows Logo Program (WLP) Device Fidelity Requirements.

Dynamic Range Test takes a noise floor measurement in the presence of signal per AES-17 and verifies that the measurement meets the Dynamic Range requirement in the WLP Device Fidelity requirements.

THD+N Test takes a THD+N measurement and verifies the measurement per the WLP Device Fidelity requirements document.

Magnitude Response Test measures the frequency response of the device and verifies that it meets the Magnitude Response requirement in the WLP Device Fidelity requirements.

In addition to providing audio fidelity logo services as described in Option 2 above, Optimal Sound also offers training on how to configure and validate the DTM, or can even setup and validate the DTM system for you. Optimal Sound also offers general training on the Audio Precision System Two and audio test fundamentals. Optimal Sound also offers schematic and layout review services , as well as troubleshooting for systems that fail to pass the fidelity tests.

Use Optimal Sound services to add an audio expert to your team, and ensure that your systems sound great, are easy to understand, and function properly with Windows Vista. Contact us for more info.