Line input is commonly used to connect electronic devices. Electronic instruments such as a computer, laboratory or any high-level signal device such as additional mixers, effects and ... The line jack is also used for series mixers and power mixers. Of course, the Line input is a Mono input. This means that this load has one channel and no separate left and right channels (Stereo). Also know that balanced sounds are called NOT balanced sounds and NOT balanced sounds are called NOT balanced sounds.
Usually in analog mixers that have both a microphone input (XLR) and a line input (TS) connector, these two should not be used at the same time. Since the input signals interfere with each other, they will reduce the level of the input sound. Of course, it's not just about mixers and if we connect two input signals to an input line to the inputs of any device, such as a computer, these two signals interfere with the sound and reduce each other's volume.
In other words, the simultaneous use of line input and microphone (Mic) interferes with the audio signals and thus reduces the sound level. It is less common for professionals to use the line input to inject microphone sound into a mixer. This input is typically used to connect other electronic equipment to mixers. Of course, I don't know the exact reason for this, but I assume that in some mixers, 48+ or Phantom Power are not applied to the line input.
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