ASIO is only available with SCS Standard and higher license levels.
The troubleshooting information below is only relevant when using the BASS audio library as your Audio Driver.
Note: ASIO problems should be a thing of the past! As from SCS 11.1.3 a new version of the BASS audio library was included which has an 'asynchronous file reading and buffering' feature. This new feature, and the associated SCS coding, appears to have completely eliminated glitches in ASIO playback. If, however, you do have problems with ASIO playback then please consider the following in order.
Increase the ASIO Buffer Size
The ASIO buffer size is set in your ASIO driver's control panel - it is not set by SCS, although SCS does use the buffer size internally. Some ASIO drivers have a very small default buffer size. For example, the Dante Virtual Soundcard ASIO driver has an default buffer size of 128 samples. If your sample rate is 48000 samples per second then this provides only about 2.7ms for SCS to populate the ASIO buffer from internal buffers. In the Dante Virtual Soundcard Control Panel you can select other buffer sizes. Select the maximum setting, which is 2048 samples (based on information in the version 3.0.x User Manual). For other ASIO devices, just try increasing the current ASIO buffer size if you are having playback problems, but not necessarily to the maximum setting as some ASIO drivers have very high maximums which could seriously impact on latency.
Increase the File Reading Buffer Length
Try increasing the File Reading Buffer Length - see Options and Settings - Audio - ASIO (Using BASS).
Do NOT use a network drive for your audio files
SCS uses a higher File Reading Buffer Length for audio files located on network drives, but even with this higher length you may still get glitches in playback if your audio files are on a network drive. If you still experience glitches then transfer your audio files to a local drive. The preferred way to do this is to collect your files into a Production Folder as explained under Collect Production Files.
Keep your Audio Files on a Solid State Drive (SSD)
If you encounter playback problems with ASIO (eg glitches) then keeping your audio files on a solid state drive (SSD) may help. With an SSD or an SD card (which is basically an SSD) there are no issues with spin down, and minimal latency.
Important Note about ASIO
If you are using ASIO outputs on your production computer (eg your theatre's PC), make sure you run through your cues on that machine before your first rehearsal, so you can sort out any buffering issues. The settings you may have had on your design computer (if it's not the same computer) may be different to those required on the production computer.