Understanding various input lines types for mixing?

Question

Can anyone out there point me to a good tutorial to understand the various kinds of inputs and outputs use in audio? I've looked around a little bit, and I have not found anything too great. Online is great, book recommendations are good as well.

I'm really trying to get a handle on the differences between things like line, mic, balanced / unbalance, etc.

I'm getting back into electronics / ham radio after a long hiatus. My ultimate goal is to create a setup that would that I can take the audio of a number of receivers, which typically have 1/8 or 1/4 inch jacks (stereo or mono) for headphones or external speakers, run them through a mixer, into something like a set of amplified computer speaker.

Thanks!

-Matt

Answer 1

Here's a great summary of the different signal levels:

Mic level is the lowest, or weakest, level signal of the four and requires a preamplifier to bring it up to Line level.

Instrument level signals live between mic and line level signals and have the most variation. You typically see this kind of signal come from an electric guitar or bass. A preamplifier is required to bring the signal up to line level.

Line level signals are the highest level signals before amplification. This is the type of signal that typically flows through your recording system after the preamplifier stage and before the amplifier that powers your speakers.

Speaker level signals are post amplification. After a line level signal enters an amplifier, it exists to the speakers at speaker level. These signals are much higher in voltage than line level and require speaker cables for safe signal transfer.

Highly recommend reading the source as it has some more info.

Source: https://www.sweetwater.com/sweetcare/articles/whats-the-difference-between-mic-instrument-line-and-speaker-level-signals/

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Regarding balanced vs unbalanced:

Balanced audio cables help protect against electromagnetic interference. Electromagnetic interference can deterioate an audio signal and introduce noise when an audio signal travels over a long, unbalanced cable.

Source: https://en.wikipedia.org/wiki/Balanced_audio

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Udemy has a free "Audio Engineering 101" course that teaches signal flow, this would definitely be a great place to start, especially as it's only 30 minutes long.

Hope this helped!