My Audio Output Ignorance

[sjemanders]

I often am set up with the audio output going through my interface to headphones, and would like to occasionally in a pinch switch to my satellite computer speakers rather than regular monitors/speakers by just unplugging my headphones from the jack and plugging the computer speaker into the same headphone out in my interface.  I discovered, however, that this does not work, and I don't actually get any sound. Why might this be? I am woefully naive with regards to this. Is there something with the signal or format that headphones can handle but run-of-the-mill computer speakers cannot? Does it have to do with frequency/sampling rate? For what it's worth, I have used these speakers before when outputting directly, rather than through the interface. 

Thank you in advance for any insight!

[David Baay]

Unplugging headphone/speakers from an onboard audio jack can signal the PC to unload the driver, but it sounds like you're talking about the headphone output on an ASIO interface, is that right? In that case, I would guess that the issue is that headphone output is wired for a stereo TRS (Tip/Ring/Sleeve) phone plug while your single un-powered computer speaker is probably a mono TS (no Ring) phone plug, and meant to be plugged into a "sister" speaker that has a stereo amp in it. Something like this:

https://us.creative.com/p/speakers/gigaworks-t20-series-ii

You might get one channel of the headpohne output from your unpowered speaker but with impedance/power mismatch, the level is probably near zero.

[sjemanders]

Yep, I think you nailed it, thank you for the help!