OSX
A few things
This week I have been using the Mac for recording, and this always brings up little obstacles to try and overcome. Mostly I had success. Here is list of what I came across:
- Using an external Hard Drive is mandatory for audio recording. I was using a 7200rpm Firewire drive so there would be no speed issues. The problem was that the connector worked loose and came out. I wasn't actually recording at the time but it is never a good thing when a drive is removed without proper dismounting. Luckily the drive was fine. The problem remains that the Firewire 800 connector is prone to come loose. In future I'll gaffer it to the computer.
- I use two monitors (or a data projector) and need to switch mirroring on and off frequently. Since installing Mountain Lion the option of having access to the Monitors System Preference has disappeared. Thankfully there is a solution: a free utility named "Display Menu".
- I now use a Magic Mouse. This has scrolling by sweeping a finger vertically or horizontally across the top of the mouse, but the default speed is far too fast when I'm using Logic. There is no adjustment in the Mouse System Preferences, but it can be slowed down by going to System Preferences > Accessibility, then click the item "Mouse & Trackpad" in the list on the left. In the new pane, click the button in the lower right named "Mouse Options...". In the new screen you can adjust the sensitivity and whether or not 'inertia' is to be used.
Project studio diagram
| project_block.pdf |
What is a plug-in?
A “plug-in’ is an optional software component designed to be used within an application programme (host). The purpose is to provide extra functionality to the main programme. For example a “Java” plug-in will allow animated graphics to run inside an internet browser window. There are several advantages with “plug-ins”. They can be used as required, so the CPU and RAM load can be less than if the plug-in features were part of the host. They can be upgraded independent of the host. Also, multiple ‘instances’ of a particular plug-in can be run (the number being controlled by the user). For audio engineering and music technology several types of plug-ins are significant. Firstly there are editing plug-ins. These are used to perform audio edit tasks such as trim, reverse.Secondly, plug-ins are used to substitute for hardware signal processors (eg equalisation, compression), or effects (eg chorus, reverb.). Some of these plug-ins emulate the exact sound and look of hardware devices with vintage models being most popular. The third type is used for music and is where the plug-in takes the form of a synthesiser. These ‘virtual instruments’or ‘soft-synths’ are inserted in a sequencer track and provide audio output, and are driven by MIDI input. In other words, a MIDI part can be recorded using a MIDI keyboard. This can then be edited as a normal MIDI track, but with a soft-synth plugged in to the track the output will be audio, and can be bounced along with any audio tracks. Virtual instruments are now available in almost all of the synthesis types (subtractive, FM, granular, additive etc). Depending upon their complexity, plug ins can take a considerable amount of CPU power. One solution is to offload the DSP (digital signal processing) functions that plugins rely on to separate hardware, known as DSP ‘farms’. Digidesign use this approach in their TDM ProTools systems. Another approach, used for soft-synths (where one instance can use the majority of available CPU power) is to use a ‘freeze’ function. This writes the soft-synth audio output to hard disk thus freeing it from the CPU workload.
OS X Audio
My investigation of how OS X handles audio streaming using Core Audio, and a look at various 3rd party audio routing utilities (including Jack, Soundflower etc).
| inter-appn-audio-osx-1.pdf |
| inter-appn-audio-osx-2.pdf |
| inter-appn-audio-osx-3.pdf |
