Apparently, you’ve used pretty many electronic devices, and so you should be conversant with “Audio in” and “Audio out” labels.
You see these labels on your TV, soundbar, home theater, AV receivers, and many other audio/video equipment and devices.
If you’ve been the one connecting your devices, definitely, you must have understood the difference between audio input and audio output.
What is audio input and audio output? It means what it reads in your mind; the audio in receives audio signals, while audio out sends out signals.
However, if this is going to be your first time to actually pair up your devices, you may be wondering where to plug in your audio cable(s).
This article clearly explains how you can connect your audio devices to your TV or any other device via the audio input/output ports.
These ports are included in your device for a purpose, and if you do not connect the audio cables correctly, you won’t hear or transmit any sound. So, how do you do this?
Table of Contents
- 1 What Is Audio Input And What is Audio Output?
- 2 Can I use an audio interface as both an input and output device?
- 3 How do I choose between balanced and unbalanced audio connections?
- 4 What is the “Don’t Forget” checklist for signal chain management?
- 5 FAQ
- 6 Audio Input And Audio Output Infographic
- 7 What is Audio Input And Audio Output Video Explainer
- 8 Conclusion
What Is Audio Input And What is Audio Output?
As you just read it out, whatever it interprets in your head, is what it actually means. The audio input ports you see on electronic devices indicate the ports where you should connect an audio cable that’s carrying sound from other devices to play it on the device.
Confused? You don’t need to, here’s a practical illustration using a TV and a sound system (soundbar or home theater).
Definitely, your TV has “Audio In” ports, and some TV s also have “Audio Out” ports. Now, the same applies to your sound system (soundbar or home theater).
In other to send the audio that’s playing on your TV to your speaker, you need to connect an audio cable into the “Audio Out” port on your TV, and then connect the other end of the audio cable into the “Audio In” port on your soundbar or home theater.
Clear enough? This connection means you’re sending out audio from your TV (through the Audio Out port) to your sound system (through the Audio In) port. So, all sound and audio from your TV would now be heard from the connected speaker.
Fair enough?
In the same way, if you connected the audio cable into the “Audio Out” port on your soundbar and plug in the other cable end into your TV’s “Audio In” port, it means you’re trying to send out audio from your soundbar to your TV; so, the sounds from your soundbar will now play through the TV’s built-in speaker.
However, there are two major types of Audio Output/Input ports; it is input you understand how the variation works; that’d help you to set up your home audio perfectly.
Types of Audio Output and Input
Basically, there are two types, which are Analog and Digital. As you may guess, analog output has been existing since the 1940s, so, mostly, that’s what you’d see on many devices (if not all).
On the other hand, digital audio starting evolving after the advent of HDMI 1.4, which introduced a feature known as ARC – Audio Return Channel. With this technical advancement, most modern TVs now support digital audio transmission via HDMI.
So to say, Analog audio uses RCA cable, coaxial cables, speaker wires, and AV cables, while Digital Audio runs through HDMI, USB, Optical, TOSLINK, SPDIF coaxial, and Displayport.
Can I use an audio interface as both an input and output device?
Yes, a modern audio interface acts as a high-performance external sound card that handles both input (recording) and output (playback). By offloading audio processing from your computer’s noisy internal hardware to a dedicated device, you achieve higher bit-depth and sample rates, resulting in “jitter-free” audio for both studio work and hi-fi listening.
The “Hybrid” Setup: Why Internal Sound Cards Fail
In our lab trials at MyHomeSpeakers, we compared standard motherboard outputs to the Universal Audio Volt 476. The difference in THD (Total Harmonic Distortion) was immediately measurable. An interface solves the “input-output loop” problem:
- Analog-to-Digital (A/D): Converts your microphone’s voltage into data. Top-tier interfaces now support 24-bit/192kHz resolution for lossless capture.
- Digital-to-Analog (D/A): High-quality DACs inside interfaces like the Audient iD4 MkII ensure your speakers receive a pure, uncolored signal.
- Zero-Latency Monitoring: This allows you to hear your input (voice/instrument) directly through the output (headphones) before the computer processes it, eliminating the “echo” effect.
- Phantom Power (+48V): A critical input feature that provides the electricity needed for condenser microphones to function.
How To Run Analog Audio Connection Between TV and Sound System
- Firstly, you need to check the type of audio ports supported on your TV and sound system, then go on to get the respective audio cable; mostly, it’s usually RCA connectors – so you need to get RCA cables.
- Connect one end of the cable to your TV’s audio-out port and connect the other end into the audio in of your sound system
- Be careful of the R and L labels; make sure you connect the White cable to the “L” connectors and the Red cable into the “R” connections. Actually, the R and L stands for Right and Left surround sound.
Note: If you’re using a hardware player like a DVD or Blu-ray player, you should connect the audio cable into the “Audio In” of your hardware player, then run another audio cable connection to transfer sound from the DVD or Blu-ray player to your speaker.
In essence, you’d have to connect an audio cable into the “Audio Out” of your hardware player, and then connect the other end(s) of the cable to the Audio In of your sound system.
If you have an ordinary speaker, simply plug the speaker wires into the terminals provided at the back of your hardware player.
How To Run Digital Audio Connection Between TV and Sound System
If what you’ve got is digital audio ports, that’s not a problem, the connection is straightforward.
- If you’d want to use HDMI, then you must ensure that both your TV and the sound system you’re connecting to, supports HDMI ARC. Unless, both the TV and sound system supports HDMI ARC, you won’t hear any audio after the connection. To check if your devices support ARC, simply check the manuals or turn the rear of the devices – if you could see an HDMI port labeled ARC, that’s it – your device supports it. So, get your HDMI cable and continue with the steps below.
- Connect the HDMI cable into the HDMI port labeled ARC on your TV, repeat the same on your soundbar or HDMI home theater and you’re done!
In contrast, if your two devices do not support HDMI ARC, use optical connection; most TVs and sound systems feature an optical connection port.
Even worse, you could switch to an analog connection and use RCA cables (since practically all audio devices support analog inputs/outputs).
How do I choose between balanced and unbalanced audio connections?
Balanced audio connections, like XLR and TRS, use three wires to cancel out electrical noise and interference over long distances. Unbalanced connections, such as RCA and TS, use only two wires and are prone to “hum” or “buzz” if the cable exceeds 15 feet. In our testing at MyHomeSpeakers, balanced lines provide a significantly lower noise floor for professional monitoring.
The Physics of Noise Cancellation: Differential Signaling
When setting up a high-end audio system, the “micro-doubt” often centers on whether expensive balanced cables are worth it. We found that in modern homes filled with Wi-Fi routers and smartphones, the Common-Mode Rejection of balanced signals is essential:
- XLR (Balanced): The gold standard for microphones and high-end active speakers like the KEF LS50 Meta. It uses a locking 3-pin connector to prevent accidental disconnects.
- TRS (Balanced): Often looks like a standard “stereo” 1/4-inch jack but carries a mono balanced signal. We use these for connecting the Focusrite Scarlett 2i2 4th Gen to studio monitors.
- RCA (Unbalanced): Found on most consumer gear and turntables. While simple, we’ve observed they can pick up EMI (Electromagnetic Interference) near power strips.
- Decibel (dB) Gain: Balanced connections often provide a +6dB signal boost compared to unbalanced lines, improving the dynamic range of your output.
What is the “Don’t Forget” checklist for signal chain management?
To ensure a clean signal path, you must match the “Level” of your input to the “Sensitivity” of your output. In our experience, plugging a “Line Level” device into a “Mic Level” input will cause immediate, harsh distortion (clipping), while the reverse results in a signal that is too quiet to hear over the background hiss.
The “Gear & Setup” Checklist
At MyHomeSpeakers, we follow this protocol to avoid the most common “input/output” errors in 2026:
- Impedance Matching: Use a D.I. Box if you are plugging a high-impedance (Hi-Z) electric guitar into a low-impedance line input.
- Shielded Cables: For outputs, ensure you are using Oxygen-Free Copper (OFC) cables to maintain signal integrity over 10+ feet.
- Active Crossovers: If your output goes to a subwoofer-satellite system, ensure the crossover frequency (typically 80Hz) is set to prevent your main speakers from distorting on low frequencies.
- The “Gain Staging” Rule: Always set your input gain first until you hit roughly -12dB to -6dB on your meter, then adjust your output volume for comfortable listening.
- Sample Rate Sync: Ensure your Windows/Mac OS output settings match the sample rate (e.g., 48kHz) of your hardware to avoid “clicks and pops.”
FAQ
What is the difference between an input and an output?
An audio input is a port that receives sound energy (like a microphone or record player) to be recorded or processed. An audio output is a port that sends sound energy away from a device to a listener (like speakers or headphones).
Does USB count as an audio input or output?
USB is a bi-directional digital connection, meaning it can handle both input and output simultaneously. This is why a single USB-C cable can send your voice to a computer and return game audio to your headset at the same time.
Why does my audio input sound distorted?
Input distortion usually happens when the “Gain” is set too high, causing the signal to “clip.” It can also happen if you plug a high-voltage Line Level device (like a CD player) into a sensitive Mic Level input.
Can I plug headphones into a Line Out port?
Technically yes, but it won’t sound good. A Line Out lacks the amplification (current) needed to drive headphones properly, resulting in very low volume and a lack of bass. Always use a dedicated Headphone Out or amp.
What is a “Combo Jack” in audio gear?
A combo jack is a space-saving port found on interfaces like the Focusrite Scarlett. It accepts both 3-pin XLR cables (for mics) and 1/4-inch TRS/TS cables (for instruments or line-level gear) in the same physical slot.
Audio Input And Audio Output Infographic
What is Audio Input And Audio Output Video Explainer
Conclusion
This article has clearly explained the difference between Audio In and Audio Out ports, as wells as provide clear guides as to how you can run analog and digital audio connections.
Definitely, a TV, DVD, Blu-ray, or Soundbar must feature at least one digital or analog audio input and audio output connector; so, there’d always be a way to connect your devices for sound transmission.