USB Class Compliant audio devices

What does USB Class Compliant mean?

If your device - such as your MIDI controller or audio interface - is USB Class Compliant, it means you can plug it into your computer and it will work without the need for any other special software (which we call drivers).

Both Mac and Windows computers come with pre-installed generic drivers. These drivers allow us to use external devices, like a soundcard or a camera, with our computers.

Since there are many types of devices that can be connected through USB, there are different types of drivers. These types are grouped into different classes, such as the USB MIDI device class, the USB Mass Storage class, the USB Video class, and so on.

An external device that is USB Class Compliant will work out-of-the-box both on Mac and Windows by using these pre-installed generic drivers.

If your device is not class compliant, it simply means you’ll have to install additional proprietary drivers on your computer. These drivers are generally provided by your device’s manufacturer when you buy their product.

Audio interfaces

Controllers that have integrated audio interfaces often have a USB Audio Class compliant audio interface. Sound cards that aren't USB Audio Class compliant need a driver for each OS. USB Audio Class compliant audio interfaces, both stand-alone and integrated into controllers, do not need any special drivers for Linux or macOS. On Windows, they can be used without any special drivers, but a driver is needed from the manufacturer to use the recommended ASIO sound API. Sound cards that are advertised for use with iOS devices are class compliant.

Unlike some proprietary DJ programs, Mixxx works with any audio interface that your operating system has a driver to use—including for timecode vinyl (DVS) use. Determining USB class compliance If you are considering buying a controller or audio interface, the easiest way to tell if it is USB class compliant before you buy it is to search for macOS drivers for the device on the manufacturer's website, even if you do not use macOS. If it is advertised as compatible with macOS but there are no drivers to download for macOS, it does not require drivers from the manufacturer on macOS because it is class compliant. If it is advertised as compatible with iOS, it is class compliant because Apple does not let manufacturers provide proprietary drivers on iOS. USB class compliant audio, MIDI, and HID devices can be used with Mixxx on Linux, macOS, and Windows.

Category:Hardware Integration

= Using Audio Interfaces =

Audio interfaces are essential for enhancing the audio quality and connectivity options of your iPad or iPhone when using Loopy Pro. This guide covers how to set up your audio interface, troubleshoot common issues, and optimize performance.

= Setting Up Your Audio Interface = Follow these steps to set up your audio interface with Loopy Pro:

1. Connect Your Audio Interface:

• USB Connection: Use a USB cable to connect your audio interface to your iPad/iPhone. If your device has limited USB ports, consider using a powered USB hub.
• Powered Interfaces: If your audio interface has a separate power supply, ensure it is connected and turned on.

2. Configure Audio Settings in Loopy Pro:

• Open Loopy Pro and go to the audio settings menu.
• Select your audio interface as the input and output device.
• Adjust the buffer size and sample rate to balance performance and latency. Lower buffer sizes reduce latency but may increase CPU load.

3. Check Audio Levels:

• Use the gain controls on your audio interface to set appropriate input levels.
• Ensure that output levels are set correctly to avoid distortion or clipping.

= Common Issues and Troubleshooting =

== Audio Interface Not Recognized ==

• USB Connection: ** Ensure the USB cable is properly connected and not damaged. ** Use a powered USB hub if your audio interface requires more power than the iPad/iPhone can provide. ** Verify that your audio interface is class-compliant and does not require additional drivers.
• Powered Interfaces: ** Ensure the power supply is connected and the interface is turned on. ** Check that any required drivers or firmware updates are installed.

== Latency Issues ==

• Buffer Size: Lower the buffer size in the audio settings to reduce latency. Be aware that very low buffer sizes can increase CPU load and cause audio dropouts.
• Sample Rate: Set the sample rate to a value supported by your audio interface. Common rates are 44.1 kHz and 48 kHz.
• High-Quality Cables: Use high-quality, short USB cables to minimize latency.

== No Sound or Distorted Sound ==

• Check Connections: Ensure all cables and connections are secure and undamaged.
• Audio Levels: Verify input and output levels on your audio interface to avoid clipping or distortion.
• Power Supply: Ensure your audio interface is adequately powered. If using a USB hub, ensure it is powered and providing sufficient power.

== Unstable Connection or Dropouts ==

• USB Hub: Use a powered USB hub to ensure a stable power supply to the audio interface.
• Interference: Reduce interference by minimizing other USB devices connected to the hub.
• Firmware Update: Check if your audio interface has a firmware update available that may fix connectivity issues.

== Phasey-Sounding or Doubled Audio ==

• Direct Monitoring Conflict: This issue often arises when both your audio interface and Loopy Pro are monitoring the input signal simultaneously, causing phase cancellation or doubling. ** Disable Direct Monitoring on Audio Interface: Refer to your audio interface manual to disable direct monitoring. ** Disable Monitoring in Loopy Pro: Go to the audio settings in Loopy Pro and disable input monitoring if your interface handles it.

== Specific Issues with Common Interfaces ==

• Focusrite Scarlett Series: Some users have reported intermittent connection issues. Ensure you are using a high-quality USB cable and that the interface’s firmware is up-to-date.
• iRig HD2: Users have experienced problems with noise and connectivity. Ensure the iRig HD2 is fully charged or powered via a reliable source and use a high-quality USB cable.