Troubleshooting Audio Problems

As of iOS/iPadOS 17.5, the OS itself manages the connection to audio interfaces and apps have little influence. In most cases, when there are problems with an audio device connection the issue is system-wide and out of the control of individual apps.

The information in this article is intended to help you get connected.

Note: Logic Pro on iPadOS has access to non-public APIs and offers connection choices when multiple interfaces are connected that other apps do not have.

The way that iOS/iPadOS works, there can be only one audio input and one audio output device at a time. The OS automatically makes the last connected device the designated input and/or output device. If a device is input only or output only, it will take over whichever function it provides. Headphones with mics are input+output devices as far as the OS is concerned. Headphone dongles -- even if no headphones are attached MAY look to the OS like an output device. Some USB hubs have built-in headphone ports. These may or may not conflict with an audio interface unless the interface is connected after the system has booted.

Bluetooth Note: if your interface is something like a SparkGo that can connect via USB or Bluetooth, use USB. Bluetooth audio (not MIDI) connections generally have too much latency for realtime music performance. Besides the latency, such devices may perform unpredictably with Loopy Pro when running in Bluetooth mode.

Preparation

These steps may seem superfluous, but rebooting and reconnecting solves a surprisingly large number of issues.

As a test project, we highly recommend that you use Loopy Pro's default project with no plugins loaded in order to ensure that there aren't complicating factors.

• Prepare a simple test project. OPTION 1: If you have a Loopy Pro project that has audio in it, you are set. OPTION 2: If you don't have a project with audio in it, disconnect your device and make a recording in Loopy Pro using the built-in mic. Save the project. You will use it later to check playback.
• Fully shut down your device using "Slide to power off" rather than putting it to sleep at waking it up.
• Disconnect everything connected to your device.
• Power-cycle the peripherals. Turn off all the peripherals that will be connected and turn them back on.
• Power the device up and log-in.
• Re-connect your peripherals.

Checking the available output devices

Use the system's Control Center to see what output devices the OS sees. The details may vary slightly on some versions of the OS. If these don't work, find out how to display Control Center on your device by searching on the web.

• Swipe down from the upper-right corner to display the Control Center.
• On most devices, the upper-right tile will be for sound output. Tap it.
• Tap on the Speaker icon (circled in the picture below) to see a list of the possible output devices. Take a screenshot if you will need further troubleshooting help.
• You should see something like the picture below that shows the names of the possible audio outputs.

If your device does not appear in the list, see the Common Issues section below.

If your device does appear:

• Launch Loopy Pro
• Open the project that you created in the Preparation step.
• Try playing the project.

If you don't hear the audio:

• Make sure the volume is turned up on your device using its volume buttons.
• Check in Loopy's mixer to see if levels show on the Master channel when playing back.
• If the audio is not working right, choose System Settings from Loopy's main menu and try a different sample rate or buffer size. Try playback again and try another sample rate or buffer size and repeat to try the available options.
• Make sure that Multiroute Audio is off by choosing System Settings from Loopy's main menu.
• Open Loopy Pro's mixer.
• Tap on the plus sign to add a hardware input channel. Take a screenshot of the options that appear.
• When the hardware input channel is added, tap on the icon at the top of the channel and take a screenshot.

If audio still does not work, launch Apple's Music app and see if the audio plays back correctly.

If you have any other audio apps or hosts, check to see if output from them works. When you contact us (see below), let us know whether you tried other apps and if they did or did not work. Please let us know the app names.

If the audio plays back correctly from Apple Music but not Loopy Pro, send diagnostics to Loopy Pro support by following the directions here. Also, send us any screenshots made during the troubleshooting procedure as well as information about your audio interface and any other connected peripherals.

When you have finished this procedure: if this did not solve your problem, send the following information to support at atastypixel.com:

• Did your interface appear in Control Center as an output option?
• After selecting, your interface as an output option, was Loopy Pro's output heard through your device?
• Is Apple's Music app or Garageband able to play audio through your interface?
• Did you try different sample rates and buffer sizes?
• Is Loopy Pro able to record from your device?

Common Issues

The most common issues are:

• Something has gone wonky. A lot of connection problems are solved by disconnecting all peripherals, rebooting and reconnecting.
• A bad cable. A lot of connection issues are the result of a cable not working properly.
• The audio interface isn't being supplied enough power. Even if the interface's lights come on, it may not have enough power to operate correctly. When this is the case, the solution partly depends on what type of iPad or iPhone you have. If using a device with a lightning connector, make sure that you are using the Apple USB adapter that includes a lightning port as well. The adapter's lightning port should be connected to a power supply. Depending on the interface, the Apple USB charger should be sufficient. In some cases, you may need a higher-wattage USB charger. You can also use a sufficiently-powered powered USB hub.
• The audio interface is not class-compliant. iOS/iPadOS devices (as of 17.3) generally require that the interface be class-compliant. While the OS technically has opened the possibility of custom drivers, there are currently no audio interfaces with custom iOS drivers.
• The audio interface firmware needs updating. This is not terribly common, but is sometimes the issue.
• More than one audio output or input device is connected. Some MIDI peripherals with USB connections look to the OS like an audio interface. Make sure that your audio interface gets plugged in after your MIDI peripheral. You will not be able to use the audio capabilities of both your interface and another peripheral that looks to the OS like an interface at the same time and there is no easy way to switch between them other than plugging/unplugging.

Volume Calibration

When using an audio interface, you may find that the input or output volume is not what you expect. This generally is an indication that the audio interface input and/or output gain needs adjusting. In Loopy Pro, 0 dB is 0 dBFS which is the loudest possible amplitude. Going over 0 dB on Loopy's meters results in distortion without increasing the signal amplitude (since the signal is literally at the highest possible value).

NOTE: To accurately compare the loudness of Loopy Pro's output to other source material, load the reference material into a new Loopy Pro project with default settings and no plugins. Often, people compare their unmastered audio to professionally mastered tracks, which typically use limiters and compressors to reduce dynamic range and enhance perceived loudness. If your sessions don’t incorporate such plugins, your audio may not achieve the same apparent loudness as the reference material.

Preparation

Before calibrating your setup:

• Shut down your iPad or iPhone using Slide to Power Off.
• Disconnect any peripherals connected to your iPad or iPhone.
• Power-cycle your peripherals if they have power-switches.
• Boot up your iPhone or iPad and log into it.
• Reconnect your peripherals.
• Launch Loopy Pro.

Output Level

If the output from the Loopy Pro mixer is at 0 dB or just below, and you feel that the volume needs to be louder, you need to increase the volume from your interface or mixer to your speakers. You may want to try increasing the volume with the volume buttons of your iPhone or iPad as they may sometimes be applied between the Loopy Pro output and the iPad output.

The volume calibration project below can be used to calibrate your system

Volume calibration project. This Test Tool project can be useful in calibrating the output of your iPad or iPhone. It has two loops that send maximum or near maximum volume. Turn down your amplifier or mixer before playing the output as the project's files are potentially loud.

Headroom. If your use-case involves live instrument input, you may want to turn down the master fader in the Test Tool project to your target output level since you may need to give yourself some headroom. For instance, you may want to turn the master fader down so that the output is at -10db if that is your desired headroom -- and adjust your interface or mixer output accordingly.

Procedure (Output level)

• Follow the directions listed above in the Preparation section.
• Open the Test Tool Project. It contains two loops. One loop is a guitar loop that peaks just below 0 dBFS.The other loop is a 0 dBFS sine wave.
• Make sure that Loopy Pro's mixer is showing.
• Leave Loopy Pro's faders where they are. They are set at 0 dB so that the output from Loopy Pro will represent the levels in the source audio.
• Turn down the output volume on your interface or mixer or amplifier (whichever is appropriate to your setup).
• Start one of the test loops playing.
• Turn up your interface/mixer volume till it achieves your desired volume.
• If your output is too quiet, double-check that the iPad/iPhone volume, if adjustable, is all the way up. (Generally, when you are using an audio interface the volume buttons on the iPhone/iPad are inactive, but in some cases they may be).

If the output level still seems to quiet, the issue is related to the signal path from your interface to the speakers or headphones.

Input Level

When recording from external inputs, you generally want to avoid the meter going into the red (over 0 dB), and you don't want the input too quiet. Generally, start with Loopy Pro's mixer at the default 0dB fader setting. At this setting, the incoming volume is unchanged by Loopy Pro. When possible, use your audio interface/mixer to adjust the level to be close to what you want and use the Loopy Pro mixer fader to make slight adjustments.

Depending on your audio interface, there may be Hardware Gain that you can adjust in the input settings panel that you get by tapping on the input's icon in Loopy Pro's mixer.

Procedure (Input Level)

• Follow the directions listed above in the Preparation section.
• Create a new project using Loopy Pro's default project.
• Choose Clip Settings from the main menu.
• Tap the Restore Defaults button found towards the bottom of the Clip Settings panel.
• Make sure that Loopy Pro's mixer is showing.
• Mute the input channel. (We are going to check to make sure that direct input monitoring is off as that often confuses attempts to set the input level correctly.)
• Play your instrument or send your signal to Loopy Pro.
• If you hear signal, direct monitor is on. Turn it off for the sake of this calibration.
• Unmute the input channel.
• Play your instrument while watching the levels of Loopy Pro's input channel.
• Adjust the input level on your interface (not Loopy Pro's mixer) until you have peak levels of at least -12 dB. Do not exceed 0 dB.
• If adjusting the input level on your interface does not result in input levels in the target range, tap on the icon at the top of the mixer's input channel. If there is an adjustable Hardware Gain setting, increase it until you get input levels in the target range.
• NOTE: most audio interfaces have some sort of LED or clipping indicator. You want the interface's indicator to indicate optimal signal level. See the interface's documentation for information about input levels.

If you are not able to get the input into the target range, check your interface to see if there is an impedance or instrument level switch.