Known Problem: Starting with Mac OS X 10.11, AudioBox VSL control software no longer works, the control panel will not pass audio (i.e. no audio input, no meters, no audio playback from system) with AudioBox VSL Software installed. Please refer to this article here that explains the issue in more detail.  
Introducing the AudioBox 22VSL from Presonus, the next generation of USB 2.0 audio interface that take hardware and software integration to the next level. Using your computer CPU and PreSonus Virtual StudioLive (VSL) software, AudioBox 22 VSL provides reverb, delay effects and the same Fat Channel compression, limiting, semi-parametric EQ, and high-pass filter, as the PreSonus StudioLive 16.0.2 digital mixer, all with inaudible latency.
Bus-powered, compact, and rugged, the AudioBox 22VSL offers two convenient front-panel mic/instrument combo inputs with global phantom power and provides two line-level outputs. It sports the same high-headroom Class A XMAX™ preamps as the StudioLive mixers and has 24-bit, 96 kHz converters with 114 dB dynamic range for clear, clean audio. And it boasts PreSonus’ legendary 150 mW headphone output, which is loud enough to explode the oysters in a Po’-Boy sandwich. (Be careful with your level control!)
The AudioBox 22VSL employs a heavy-duty steel case and this mighty mite fits in just a third of a rackspace and can be screw-mounted to a standard rack tray.
VSL enables you to easily manage the processing and mixing from your Mac or Windows PC and provides editor/librarian functions, making it simple to create and use a library of presets. Presonus include the same library of more than 50 Fat Channel presets that comes with StudioLive mixers. These presets were created by professional musicians and engineers and let you instantly set up dynamics processing and EQ for vocals, guitar, and much more.
Seamlessly integrated with the included Studio One Artist DAW recording software, the AudioBox 22VSL interface works with virtually all Mac and Windows audio-recording software.

Key Featuures

• 24-bit / 96 kHz 2 x 2 USB 2.0 recording interface
• 2 dual-purpose front-panel input channels, each with:
• Combo XLR mic and balanced ¼" instrument input
• Class A XMAX™ mic / instrument preamp
• Individual channel-trim controls with 0 to +35 dBu mic gain range
• 48V phantom power for condenser microphones (global)
• Mixer control (blends the input signal with the computer playback stream for zero-latency monitoring
• Headphone jack with level control
• Main-output level control
• LED clip indicator for each channel
• Studio One Artist digital audio workstation software included
• Virtual StudioLive™ (VSL) control software included