Motherboard 3.5mm or HDMI for audio?

[KuJoe]

In the past when I did tests I would use the 3.5mm line-out jack on my motherboard for audio and it sounded better than audio over HDMI did but last week while I was streaming I decided to play music on my gaming PC instead of my streaming PC and I noticed how awful it sounded (very distorted/muddy). In terms of hardware which should be the better quality, 3.5mm or HDMI? Should I switch from the 3.5mm jack to HDMI to get better sound from my gaming PC to my streaming PC or is there something else I should look at first (maybe a setting or other software solution)? Thanks!

[mariushm]

As always the answer is  IT DEPENDS on your hardware.

 

Modern onboard audio is pretty good, with low noise floor, isolated from rest of pcb so minimal or no buzzing etc etc. Some motherboards even have high quality DACs and opamps, some even removable for user upgrade.

The HDMI audio is DIGITAL, like Toslink or Coax digital out on regular sound cards - quite a lot of motherboards still have the digital out headers and you could buy brackets with tosklink or coax digital separately and add this functionality to your onboard sound.

You can send the sound either uncompressed or compressed, compressed is simple for stereo and even 5.1, you have the bandwidth.

The benefit with digital is that the sound doesn't go through a DAC to get digital to analogue quality losses and the audio data can not be affected as it goes through the cable if the analogue audio cable isn't shielded properly...

 

Your problem is what happens at the end, where the digital signal is converted back to analogue audio.

If you have a good audio receiver with HDMI inputs, then of course the sound will sound great, because that audio receiver most likely has great DACs and opamps and good quality audio amplifier inside. 

But if you have for example a monitor with a cheap DAC and a 2-3$ 5w class D audio amplifier inside with headphones out ... that has the potential to sound worse than onboard sound, with distortions at high volume, all that unwanted crap.