Testing Mac Audio

This information has been created for users to try and test a different version of Rat that appears to work better than the current version 4.4.01 which comes with Access Grid Toolkit.

Kudos firstly should go to the guys at the Access Grid support Centre (AGSC) in the UK, who ask me to test their PAG (Portal to Access Grid) in which I found by testing the PAG, that the Mac audio was a lot more acceptable than the current version.

There are two ways to try out the suggest version of rat:

  • Try using PAG -, only requirement is to have a java enabled browser.

    • The developers have asked me to inform you that the system is still in “Beta”, but from my initial testing, it appears to work reasonably well.

    • Additionally, feedback it very much welcomed. Please ensure you include the OS, browser and java version with reports.

  • For those who would like to continue to use the Access Grid toolkit, you can change the current Audio Service simply by:

    • If you have tried out the PAG, a pag directory with the AudioService should have been created. Copy the contents of this directory to the Access Grid AudioService directory. Example:

cp -r pag/local_services/AudioService/*

.AccessGrid3/local_services/AudioService {One line command}

Additionally, you will have to edit the “rat” script and pointed it to use version 4.4.00.

    • Alternatively, if you do not wish to try out “PAG”, you can download the file AudioService.tar and extract the contents by executing the following:

Download the file (which can be found at files/AudioService.tar.gz) and save the file to home directory.

cd ~/.AccessGrid3/local_services/

tar –zxvf AudioService.tar.gz .

Hopefully, using either method will allow you to use Version 4.4.00 which should work better than current version.

Note that this version is still limited to 8bit sampling, but it appears to be a lot more stable and doesn't produce the “garbled” audio as often.

It has been found that an occasional restart of audio is required now and then, but tests has shown the audio capable of running all day without a required restart.

Enjoy and please feel free to provide feedback to the AG-Tech mailing list (see for information on the various mailing lists).

Known Problems and Solutions

Problem: By switching devices and modifying the device properties may cause the quality to drop and cause issues.

Solution: Simply disable and then “re-enable” audio, will resolve this problem.


Problem: There are some lip sync issues, with approximately a half a second lag between video and audio.

Solution: There really isn’t a solution at the moment, but if you disable and then “re-enable” audio, this may reduce the lag, as it “might” get worse over time.