Some works on the austraLYSIS site are four channel (quad audio). They are optimised for listening with the Safari browser, on Macintosh OSX >=10.12. This page provides information to help you to check that you system is set up correctly; and includes a simple test file in which the channels are identified verbally.
The austraLYSIS and soundsRite (www.soundsrite.uws.edu.au) websites provide several four-channel (quad, 4.0) audio works. These play directly in the Safari browser in the HTML5 audio tag, and are optimized for use on a Mac with OSX 10.12. In most cases the original uncompressed versions (CD quality, 44.1Khz, 16 bit) have been presented additionally in compressed versions, prepared using the ffmpeg encoder. As of 201706, On OSX, Safari can play properly all the files presented, but Chrome and Firefox cannot. The four-channel audio files have the following formats and audio channel layouts:
a)Quad audio files, presented as 4 discrete channels. The four channels are (numbered sequentially) 1= Left Front(LF), 2=Right Front(RF), 3=Left Rear(LR), 4=Right Rear(RR). The listener should be at the centre, equidistant from all the speakers. In some cases there are CD quality versions, and also lower quality (smaller file size) versions (mp4). In ffmpeg and several other systems, the Quad set up we are using is termed 4.0 (no LFE included in the description). (Note that Quicktime, which is not used here, may identify the channels differently.)
b)Files of type a that can be downloaded for local listening under more optimized conditions. On a Mac, you do this by control-clicking in the audio controller bar. In addition, some may be provided as zipped files to ease the download process.
Note that several of the files are quite large, and hence they are coded in the webpages such that the available duration is displayed only when the browser estimates that it can be played through completely without stutter (using the 'oncanplaythrough' event of the HTML5 audio tag). You may need to be patient for this, depending on the speed of your connection, and the size of the particular file; in cases of long delay, consider the download alternative. You need to set up your hardware (digital audio interface) and cabling from your computer and to your speakers correctly for these files to be spatialized correctly. Your hardware will probably refer to the channels as 1-4, though if you have an LFE (sub-woofer) other numbering may be used. There are also many variants: for example on MOTU digital audio interfaces such as the Ultralight series, 1,2 are called L and R Main, while higher numbered channels are called 'Analogue Out 1 ….n'. A simple test file which verbally identifies the channels is available below. This file sounds the 4 channels (LF, RF, LR, RR) successively and individually, and the spoken voice identifies the sounding channel. If you use a Mac, you can also test your speaker set up using the AudioMidiSetup app, available in the Utilities folder of your Applications directory. The set up we are concerned with is called 'quad'.
As of 201706, our web pages and files are functional on Mac OSX, with either Safari (which can play all the files provided) or Chrome (which can only correctly play the uncompressed .wav files, and not the compressed files). Firefox presently does not play multichannel audio in the HTML5 tag. HERE IS A TEST FILE, which verbally identifies the four channels as they play invididually. This is a very rough recording solely to aid in checking your set up. As a channel is named, the other channels are silent.
A four channel test file. The file is quad (Wav file, four discrete channels, 4.0), so that you can check and adjust your system. Each channel (Left Front, Right Front, Left Rear, Right Rear) is identified verbally; at the same time, the other channels are silent. It is 4Channel .wav uncompressed audio, in the HTML5 audio tag. As of 201706, Macintosh OS 10.12 plays multichannel audio correctly in Safari and Chrome (given suitable hardware). Firefox does not play multichannel audio; it only provides at best a stereo mix. (Four channel audio test file) | 2017.
MORE DETAIL ON THE FILE TYPES: CD quality, uncompressed files (44.1Khz, 16 bit) are presented in .wav format. These play as multichannel files, channels 1-4, on both Safari and Chrome on Macintosh OSX 10.12. They are not fully functional on Firefox. (Flac lossless compression files are unfortunately not fully functional in any Macintosh browser as of 201706.). Compressed files (44.1Khz, 16bit) are presented in mp4 format (aac compression). These play correctly as multichannel audio, channels 1-4, only on Safari on Macintosh OSX 10.12. They are not fully functional on Chrome or Firefox.