Line In And Mic In

Differences Between Line-In And Mic In

Are you wondering if you should use a line in or a mic in for plugging your audio device into a receiver? How do you know if you should use a line in or a mic in? It may not have occurred to your mind, but there’s a significant difference between line in and mic in. The two refer to the voltage level of signals.

However, there’s a difference between the voltage for all kinds of signals. A mic-in is an input people use to connect wired and wireless mics. The level signal is a type of signal that a mic creates. On the other hand, a line-in is an input that powerful devices can use like musical instruments and audio equipment

Can A Mic-In Be Used As A Line-In?

As mentioned earlier, a mic-in is an input that wired and wireless microphones use to connect. The level signal is a type of signal that a mic creates. A mic-in and a line have a huge difference, and you cannot use the mic-in as the line-in. Very complicated and updated devices use a line in. In contrast, a line in is a jack in the computer system cards that connect external devices like microphones, CD players, musical equipment, etc.

What Are The Differences Between A Mic In And A Line In?

A mic in and a line in have many differences. Some of them include:

Voltage Difference

A mic level signal Is created by a mic when collecting sound that is around 1000th of a volt. Line signals are 1000 times stronger than mic-in jacks. That is why you can’t use a mic-in as a line-in. The voltage may be different according to the changes in the signal of a source and levels of sound. 

A system has four types of audio signals, with the weakest ones being the mic level. That is why a microphone should have a pre-amp for converting the signals to line level.

Input And Connectivity 

Mics and lines don’t operate on one input. A-line signal will move from the pre-amp to the amp working the speakers. There are two standard line levels, including MP3s, DVDs, and other equipment. These have a -10 DVB. The other is for professional equipment such as desk mixing and devices for processing signals with +4 dBu.

When connecting a record player and turntable, it’s a different thing. The retro devices have varying frequencies suiting their needs. They have pretty similar inputs with mics at 5 mv. Still, the mic will not work with this kind of input. Plugging one will cause a weird sound that will be thoroughly mixed up.

Converting Signals Difference

The market is full of devices that you can use to convert a mic level and a line signal. The mixer is one of the most common devices to combine various signals to make one output. You can also convert the mic to a line using pre-amps, mic to line amplifier, and different multi-channel devices.

You cannot use a line input in a mic input. It will produce a soft and barely audible sound that is hard to hear. A mic input needs nearly -5 mv as CD and MP3 music player, creating a 100+ mv mic input. If you have such a device, it would be best to use a line input. 

A mic is used for mic inputs, and most audio devices such as computer equipment and professional ones use line-level signals, so what happens if you change the inputs? Will the equipment get damaged if will you hear a sound? 

Connecting a line-level input to a mic input produces a loud and distorted sound. This occurs since line signals can be stronger than what the mic input will accept. Nonetheless, the input and output in various updated mixers can be switched from a mic to a line level.

Connectors And Accessories Differences

A mic and a line-level will use varying audio connectors; a mic-level input needs a female XLR connector. A line-level input requires a phone jack of about ¼ -inch, an RCA jack, and a phone jack of 3.55 mm. It is hard to miss anything with mic and line levels since it is indicated in many audio pieces of equipment.

If you only see one mic input in a piece of equipment such as a computer or digital audio recorder, you should use the line-level converter. The converter is connected to a mic input to reduce the voltage. Some people also use a signal attenuator box. 

It would be ideal always to use the correct cables for a safe signal. Some types of cables come with inbuilt resistors for reducing line level voltage.

If you are using wireless receivers, you will find varying outputs. If you are not sure, you can refer to the instruction guide of your device to check for the output signal levels. You will realize that the level signals of the mic are different in various receivers. The difference can be 20 dB high.

Which One To Use Between A Line In And A Mic In?

The one to use will depend on your device. If you use a different device from a microphone and connect it to a mic-in, you will overload the signal and create a faint sound. It’s essential to countercheck the equipment you want to plug in. it’s safe not to mix two inputs, and in case it happens, you should quickly change the device’s input signals.

You can reduce the output by reducing the device’s output or including a different signal path. The first option is straightforward and effective but affects the signal-to-noise ratio. If this happens, you should go for the next possibility of including a different signal path by utilizing a unique audio device.

Does A Headphone Go In Line Out Or Line In?

Headphone Go In Line Out Or Line In

A headphone does not go inline output or line input as line-level ports don’t have an inbuilt amplifier. Therefore, they are not powerful enough to work the headphones. Doing this will only produce less or no sound to the headphones after plugging them into line output. 

A headphone port is different from a line out. Headphones have built-in amplifiers, making it possible to work the headphones and produce quality sound. A microphone also has a weak signal and cannot be transmitted through a line input. 

Therefore, you should connect the microphone to the mic-in as they have an in-built pre-amp. The pre-amp gets the weak microphone signals and boosts them into a line-level signal. So, what you need to know is that when you need to connect the microphone to a device with only a line-level input, you should plug in your microphone to a dedicated preamplifier or mixer before you connect it to the line-level input.


If you ever wonder whether to use line-in or mic-in, you should remember that the two have different signal levels. A mic has the weakest signal voltage, which may change based on the source and distance of the sound. Enhancing the intensity is only possible if you take the mic to line signals.

Please read the instructions manual of your device to establish whether it is compatible with line-in or mic-in before plugging in.