My AudioBox is producing or recording noise. What do I do?
posted this on April 17, 2013, 3:27 PM
Q: My AudioBox is producing or recording noise. What do I do?
A: The AudioBox series should be able to record and reproduce a relatively clean signal, free of noise. Below are common reasons for the input and/or output to produce unwanted noise, as well as potential fixes for these issues.
When recording, you will want to make sure that your environment is as free of noise as possible. Microphones, especially condenser mics, can often pick up sounds that are either inaudible to the human ear, or so common that they are easily ignored. Common causes of environmental noise include:
Physical vibrations produced by speakers
To troubleshoot environmental noise, you will want to try and attenuate these sources as best as possible. Try moving the mic away from the computer, turn off any fans and/or air conditioning, and close any windows that may be present. If your environment is too noisy, you may wish to invest in soundproofing solutions, or use a mic isolation booth.
The Noise Floor
All digital devices that provide amplification have a certain recording level known as the noise floor. This is the level of "gain" or amplification applied to the channel that will cause the channel to produce noise on its own. For the AudioBox USB, if the input gain is turned to the maximum, or near maximum, static or "white noise" sounds may appear. This is normal for almost any recording interface, and is an inherent facet of digital audio.
To solve this issue, you will want to record at a lower level. Try turning the gain down for the channels you are recording; on the AudioBox, these are the knobs labeled 1, 2, 3, etc. If you find that you must max the preamp gain out to receive a signal, investigate your mic and cabling to make sure that they are functioning properly.
Note: The AudioBox USB and AudioBox 22VSL devices are powered entirely by the USB port on your system. Unlike high-powered professional preamps and mixing consoles, bus-powered devices may have issues amplifying signals from microphones with high impedance ratings.
This could result in being forced to turn the gain control for your input channel to maximum to receive a noticeable signal, resulting in noise issues. For more information on microphone impedance matching, check out this link.
If you have a microphone that cannot be adequately amplified by the AudioBox, you may wish to invest in a preamp, which you can then connect to the AudioBox's inputs via a direct box or DI. Conveniently, PreSonus makes a wide variety of preamps that will fit almost any need. They can be located here.
The AudioBox USB can sometimes be subject to grounding issues if powered by a system that is either not properly grounded or is receiving power from an unstable source. The following options may rectify grounding issues:
If using a laptop, try running off of the laptop's battery power. If the noise disappears, check the laptop's connection and make sure it is being powered by a clean source
Try a different USB cable. Make sure to not use one that exceeds 3 meters, or around 9 feet
Connect your system to a professional power conditioner
Check the electrical lines in your studio or residence, or try using the device at a different location
Input Sources / Output Solutions
Noise can also be caused by malfunction in your input sources. You will want to check any input sources you are using (microphones, guitars, etc.), as well as their cabling, with some other playback solution.
Additionally, noise can often be caused by issues with studio monitors and/or headphones. Check your monitors, headphones, and/or cabling to make sure that these playback solutions are functioning properly. PreSonus recommends using balanced connections to connect your AudioBox to your studio monitors.
For more information on eliminating noise in your playback solution, check out this article.
Can noise be a software issue?
Noise can also be produced by driver and software issues. Before attempting to diagnose any software issue, first check to make sure that the noise is not being generated by the inputs of the device.
On the AudioBox USB, AudioBox 22VSL, and AudioBox 44VSL, there is a knob labeled Mixer that will allow you to change the playback stream to monitor the computer, the inputs, or a mix of these signals. Try unplugging all input sources, turning this knob all the way to the left, so that it is seated on "inputs", and listen to your speakers or headphones.
If the noise is still present when monitoring the inputs directly, it could be a hardware issue with the device. Check for the conditions above to rule out any other situations besides malfunction. If you believe that the device itself is producing this noise, please contact our technical support department for further troubleshooting.
If the noise disappears, then most likely the device itself is functioning fine. In this instance, you will want to check the following:
Disable any WiFi or Bluetooth adapters on the system; these are common causes of digital noise
Reinstall the device on a different USB port on your computer
Make sure you are not using a USB 3.0 port; for more information on this, please see this article
AudioBox VSL devices contain internal effects known as the FatChannel bus. These effects include a compressor and an EQ. If improperly configured, over-compression or extreme amplification via the EQ can cause noise issues to appear much more prominently. Try disengaging any FatChannel effects in the AudioBox control panel to make sure that these effects are not amplifying the noise floor.
Make sure that the buffer is not set too low. On a PC, open the AudioBox control panel, select Setup (AudioBox VSL users only), and raise the ASIO Buffer Size to a higher value. On a Mac, the buffer setting is changed from within your DAW software, usually under Preferences -> Audio.