Preferences can be accessed via the “cmd+,” key command, or in the ALK->Preferences… menu item.
The audio preferences pane encapsulates settings related to the audio interface and audio callback buffer size. For both inputs and outputs, you can choose from the following settings:
- Device: this combo box allows you to choose which audio interface is used for input purposes.
- Terminals: this list view allows you view, and modify the names for the set of terminals detected for the current device. Name changes for terminals are reflected elsewhere in the user interface. For example, if you change the name of “Input 1” on, say, your RME Fireface sound card to “Roby’s Guitar DI”, it will be much clearer and simpler to select inputs correctly for your guitar tracks.
- Restore Button: pressing this button returns the audio system back to the default state: each terminal is restored to its original name.
- Audio Buffer Size: an audio host such as ALK works by processing
audio in chunks; so-called audio frames. The size of the buffer
impacts ALK in two ways:
- latency: as the buffer size increases, the latency of the entire audio system increases commensurately. If the buffer size is too high, there could be a noticeable delay between the original and monitored signal.
- load on the system: as the buffer size decreases, the load on the CPU is increased. This is because the buffer – which is now smaller and thus represents less time – needs to now be filled more often, and this in turns increases the CPU load. If the load on the audio thread is too high (for example, if you are running many or CPU-hungry audio plugins), you will hear stuttering and glitches. If stuttering or dropouts become a problem and you’re not able to increase the buffer size (e.g. because the latency becomes unplayable), then you must reduce the CPU load in the audio thread by removing instances of certain plugins, or even tracks.
- Sample Rate: Here the sample rate can be changed to any rate supported by a connected audio interface.
- Graphics: This check box switches on and off graphical glow FX and limits the frame rate to 30 FPS. Uncheck this option if continual CPU problems are encountered.
It’s a good idea to experiment with the Audio Buffer Size in your program. Your goal during experimenting should be to dial down the buffer size as much as possible without inducing stuttering or glitching in a project somewhat larger and heavier than the typical project you use. This way, you still have the proverbial extra headroom if your track needs that extra gear change!
The MIDI device list displays the currently detected MIDI hardware devices (such as USB keyboards or drum pads). For each detected device, a row appears in the list view. Click on the device name to change its name (for example, changing “nanoPAD2 PAD” to “Ray’s Drums Pads”).
In addition, you can disable or enable the MIDI device by clicking on the check box on the device row. If a MIDI device is disabled, you will not receive any input from the device.
The plugins pane allows you to scan for VST/AU plugins, based on a list of search directories. The scanning process looks at each search path in turn, so if the same plugin appears in two search paths, the plugin in the first search path will be used in ALK.
- Plugin Directories - this list view displays the directories that will be
searched for plugins when you click Rescan. The controls below
the this list view are, from left to right:
- Add Directory (‘+’) - this adds a new place to search for plugins;
- Remove Directory (‘-‘) - this deletes the currently selected directory from the list;
- Increase Priority (up arrow) - this moves the directory up on the list;
- Decrease Priority (up arrow) - this moves the directory down the list;
- Restore Defaults - pressing this button causes the search paths to be reset to the default AU and VST search paths on macOS.
- Plugins - this area consists of:
- a table view which displays the currently detected VST and AU plugins, along with some of their properties, such as Plugin Vendor, plugin type (Instrument or FX), etc.
- Rescan - this button causes ALK to scan for plugins, which is described in more detail below.
Scanning For Plugins¶
When you click Rescan, ALK begins traversing the plugin directories displayed above. When it finds a file that looks like it could be a plugin, it tries to load the plugin. If successful, the plugin is added to the list of detected plugins (note that this is only reflected in the listview when the entire scan operation has completed.
Scanning is a process that can take a while, so while ALK scans for plugins in the background, you can continue using the program. Scanning progress is displayed in a panel showing the plugin currently being scanned, and the overall progress.