I have headphones and some simple AmazonBasics stereo speakers (like $13).
They both work great. The AmazonBasics speakers are amplified, powered by USB or batteries. The headphones (Razer), unfortunately, are not amplified.
The goal is simple: I want all stereo audio to come through both. I don't want surround sound, and I don't want just part of the sound to come out one or the other.
Since the headphones are not amplified, cheap audio splitters are out of the question, and honestly shouldn't be necessary.
A few problems...
Realtek's Speaker fill option when you switch to something like Quadraphonic is total crap. The device plugged in as the back always sounds like it's had the lyrics removed from anything; TV, songs, movies, etc. It affects both devices, whichever is plugged into the back port. Why they assume this is desired is beyond me; it's not.
How can I do this?
Similar question: Use all 5.1 speakers with a 2.1 audio source (Unsolved really; the solution there was only for Winamp. I want this to work EVERYWERE. From YouTube in Chrome to games to VLC to anything!)