What is the difference between line in and out jacks and mic and headphone jacks? Can line in and out jacks be found on front IO?

[HasiTheAvenger]

Can someone explain the difference between the two? 

[RAGNES7]

one is for Audio input, other is for audio output.
Thats how the OS will recognize the devices properly.

The front IO wont be as good as the rear once sonce, the rear is directly connected to the Mobo audio channels and is shielded from other parts of mobo

[Eigenvektor]

Line in is for external audio devices. It typically expects a stereo signal with a certain signal level. Mic in is for microphones, it accepts mono and usually has a pre-amp to boost the signal's level. Similarly line out is intended for external audio devices that have their own amplifier, while headphone jack is for a headphones.

 

Front I/O usually only has mic/headphone, afaik

[mariushm]

The connectors on the front panel are typically less shielded (just a cable going a long way passing various hardware to reach the top of the case from the bottom of the motherboard) so there's risk of getting noise into the audio signal from hardware in your computer.

 

The cable from connectors are going into the audio sound card chip in like a "audio switch" part of the audio chip - the chip tries to auto detect the kind of signal is present in the jack and auto detects as microphone (low voltage signal that requires preamplification) , line in (pre-amplified signal coming in), or headphones (higher impedance than speakers) or line out. You can also specify manually what's plugged into the jack on modern sound cards.

 

So basically that's how instead of headphones out, you could configure the front panel jack to be another jack for a 7.1 speaker system, or you could have line out from the front panel connector/

 

The chips typically have several ADCs (analogue to digital conversion) to convert microphone and line in signals to digital and pass to computer, but there is in most chips a group for the IO shield and a group for front panel - and the ones for front panel typically have less precision, less quality, a bit more noise, they're not as high end as the ones used for connectors on IO shield but it's good enough.

Still if you want absolute best quality, using the connectors on the IO shield is better,  or alternatively go around the sound card completely and use a USB sound card or a USB DAC.