How do I set audio output as input?

What does setting audio output as input mean?

Audio input and output devices refer to the hardware components that capture sounds as input or play audio as output. An audio input device like a microphone captures sounds and converts them into an electrical audio signal. An audio output device like speakers or headphones convert an audio signal into sound waves.

Routing or redirecting audio output back into input means taking the audio signal that is being sent to an output device and instead using it as the input signal for another purpose. For example, you could take the audio playing from your speakers and route it to act as the microphone input in a video call. This allows you to apply live effects or echo to your voice during the call since your voice audio is being fed back into the input.

Some common use cases for routing audio output to input include:

• Creating an “infinite” effects loop, like an echo or reverb that keeps looping back through.
• Using DAW playback as a sound source for live performance or streaming.
• Applying EQ, compression, pitch shifting or other effects processing to playback audio.
• Combining multiple audio sources like music playback and a microphone.

When would I want to route audio output to input?

There are a few key reasons why someone may want to route their audio output back into an input source:

• Creating feedback loops and echoes – Routing audio output back into the input creates a loop that leads to feedback, distortion, and echo effects. This can be done intentionally for creative purposes in music production. Some hardware effects units like delay pedals work by creating this kind of loop.
• Chaining effects – Audio processors like EQs and compressors can be chained together by routing the output of one effect into the input of the next. This allows for extensive audio processing and combining of effects.
• Sampling own audio output – Musicians can route their live playing or full mix output back into their audio interface input to record the audio. This allows musicians to sample their own performances.

These methods allow for creative sound design and music production techniques by manipulating the audio signal flow. Routing output to input opens up possibilities beyond just working with dry input sources.[1]

Requirements for routing audio output to input

To route audio output back into an input source like a microphone requires a few key pieces of hardware and software:

Audio interface or mixer with stereo inputs and outputs – You’ll need an audio interface, mixing board, or other device that has both output jacks and input jacks you can access. This allows you to patch cables from the outputs to the inputs directly. Many basic consumer audio interfaces may only have outputs, so having full input/output capability is key (Ryan O’Hanlon).

Cables to connect outputs to inputs – You’ll need the proper cables to route signals from your interface’s outputs to its inputs. Typically dual 1/4″ TRS cables are used for this. The outputs and inputs need to be compatible in terms of impedance and signal level.

Software or hardware to manage audio routing – You’ll need some way to actually route the audio internally from the outputs to the inputs. This can be done in a digital audio workstation (DAW) software or directly on a hardware mixer. The capability to flexibly route audio is required.

Setting up the signal routing in software

Most DAWs and audio workstations have built-in routing capabilities that allow you to route audio output back to an input. This is done using the software’s I/O matrix or routing window.

To route audio output to input in your DAW or workstation:

1. Open the I/O settings window, which may be called “Routing”, “Audio Connections”, or something similar.
2. Locate the output channel(s) you want to route.
3. Assign those outputs to route to desired input channels.

For example, you may route your master stereo output to channels 1-2 to use the master bus processing while recording.

One key setting here is to enable software monitoring to avoid latency. This allows you to hear the audio being routed in real-time without delay. Depending on your software, look for a “Software Monitoring”, “Low Latency Monitoring”, or “Direct Monitoring” option.

Routing the output to input internally within your DAW provides flexibility in your workflow. Just be sure to gain stage properly and watch your levels to avoid clipping or distortion.

Setting up the signal routing with a hardware mixer

To route audio output to input using a hardware mixer, you’ll need to use the available aux sends, insert points, and effects loops. Here are some tips:

Connect the output of your audio interface, instrument, or other source to an input channel on your mixer. Then connect that same channel’s output (aux send, insert point, etc.) to another unused input channel. This creates a loop from the output of one channel into the input of another.

Most mixers have dedicated aux sends on each channel that you can use for this purpose. Turn up the aux send level for the channel you want to route. Then connect it via a cable to a spare input channel to complete the loop.

Another option is to use insert points, which are input/output jacks that let you insert external effects into a channel. Connect the insert send into an input channel return to route audio.

Some larger mixers also have built-in effects loops or insert loops designed for this kind of signal routing. Check your mixer’s manual for details on utilizing these loops.

The key is understanding the signal flow and using the right outputs/inputs to create your routing. Keep gain staging in mind and watch your levels to avoid unwanted distortion.

Some advanced mixers like the BEHRINGER X32 (https://www.behringer.com/product.html?modelCode=P0ASF) allow you to route outputs to inputs internally within the mixer’s software/firmware.

Gain Staging Tips

When routing audio output to input, proper gain staging is crucial to avoid issues like feedback, distortion, and poor signal-to-noise ratio. Here are some tips for optimizing gain levels:

Start with very low output levels to avoid feedback. Feedback occurs when the signal loops around and reinforces itself, causing an unpleasant howling or squealing. Keep the initial output gain low, around -20 to -10 dB, then slowly increase it while monitoring the return input levels.[1]

Slowly increase the gain while carefully monitoring levels at each stage. The goal is to achieve the highest signal level possible without clipping or distorting the input. Watch the input meter and make sure it never reaches the red. Turn the gain down if you hear distortion.

Use EQ cuts and noise gates to remove unwanted frequencies. EQ cuts can remove resonant peaks that lead to feedback. Noise gates can mute the return signal when it falls below a set threshold, preventing noise buildup.

Proper gain structure from output to input is key for a clean, quality signal. Take your time and adjust levels gradually. It’s better to have a lower but clean gain structure than a loud but distorted signal.

Creative Uses of Output to Input Routing

One creative use of routing audio output back into input is to create psychedelic echoes and looping effects. By taking the output from your audio interface and patching it back into an input, you can generate feedback loops and layered echoes. This technique was popularized by psychedelic rock groups in the 1960s who would route their guitar amps or keyboards back into the mixing board to generate trippy, repetitive echoes. Today this effect can easily be recreated in a DAW by setting up an auxiliary track to route audio output back to input.

Another creative technique is sampling and resampling your own audio. For example, you could route a vocal track out to your audio interface output, then back into an input to resample it. Adding effects like distortion or pitch shifting in between the send and return creates interesting mutations of your original audio. Resampling allows you to continuously transform a track by routing it through different effects chains. Each pass changes the audio and generates unique textures.

Routing audio output back into external hardware effects is also a popular creative technique. You can utilize guitar pedals, rack effects, or other outboard gear to process your sound, while retaining the flexibility of your DAW mixing. This allows you to incorporate the classic sound of analog effects devices into your digital productions.

Troubleshooting Challenges

When routing audio output back into input, it can lead to some common issues that require troubleshooting:

Fixing feedback, distortions, clipping – Sending audio output back into the input at high volumes can cause unpleasant feedback, distortion, and clipping effects. Reduce the output volume, adjust gain staging across devices, use a limiter or compressor, and ensure levels are not peaking above 0dB.

Latency compensation – Output to input routing introduces latency as the signal is processed. Use drivers/software supporting low latency monitoring, compensate with track delay settings, or record through the latency for timing alignment later.

Monitoring direct unprocessed signal – When monitoring through a DAW, you may hear distracting effects. Use “direct monitoring” or “software monitoring” features to hear the dry input signal unprocessed.

Other tips include muting headphone/monitor feeds to avoid feedback, using DI boxes or audio interfaces with better conversion, and routing through external mixers. Careful gain staging and monitoring for distortion is key.

Alternatives to routing audio output to input

There are a few alternatives to routing audio output to input that allow you to process sound without creating a feedback loop:

Using external effects devices – Dedicated hardware effects like reverb units, delays, chorus pedals, and multi-effects processors can be inserted into your signal chain to process sound. This allows you to add effects without routing the output back into the input.

Software effects on channel inserts – Most DAWs and mixing boards allow you to insert software effects as inserts directly on a channel. This processes the sound on that channel only, without sending the output back to the input.

Auxiliary buses for effects sends – Sending tracks to an auxiliary bus allows you to process multiple channels with the same effect while avoiding feedback. The aux send controls blend the dry and effected sound.

These options allow you to get creative with sound processing without running into the challenges of feedback that can occur when routing audio output directly back into the input.

FAQs about Setting Audio Output as Input

Setting audio output as input allows you to route the audio from your computer’s speakers back into the microphone or line input. This technique has many creative uses, but can also lead to confusion. Here are answers to some frequently asked questions:

What is meant by setting audio output as input?
This refers to using software or hardware routing to take the audio from your sound card’s output and redirect it to become input audio. For example, routing your computer’s speaker output back into the microphone input.
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Why would I want to do this?
Creative reasons include adding effects or modulation to your mic sound. More technical uses involve monitoring audio without latency or creating feedback loops. It allows new ways to mix and process sound.
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How can I prevent feedback issues?

Use gain staging to lower the looped audio volume. Avoid routing the master mix which contains microphone input. Use software monitoring options if available. Add a noise gate to cut signal when not speaking.
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In summary, setting PC audio output as microphone input opens creative possibilities, but requires care to avoid unwanted feedback. Start with a loopback cable or simple software routing to experiment with this technique.