Having a strange issue and can't pin it down.
A few months ago I was able to stream anything from my PC to my Chromecast and it would play it fine on my TV (Sony Bravia), through some Microlab stereo speakers connected to tv via Audio Out. I was using the Videostream extension for chrome. So around September I wondered if there was a more up to date version of Videostream, and I found that now they had released a Windows app. So I uninstalled the chrome extension version, removed all traces manually, then installed the windows app version. I found that flac files sounded terrible, or they didnt play at all, when I selected PCM audio in Videostreams settings (what I was using previosuly), and average at best with AC3, and terrible with the default 'stereo' option. So I uninstalled, reinstalled the extension version, but same thing. I tried all the fixes suggested by Videostream devs but nothing worked, and I thought it must be related to videostream.
Next I tried Plex. Flac files sounded terrible, despite hours of googling, tinkering, and sifting through log files. So I thought I'll just switch over to mp3, I can live with that, must just be a flac issue with Videostream and Plex. Nope. Same thing with mp3's, or at least, files where the music is quite heavy or there is a bit of bass. Bear in mind, movies seem to be OK with both Videostream and Plex, although I did have some problems with Videostream at first.
So then I thought, OK screw you apps, I'm going to get a long HDMI cable and plug it directly into my TV. So I tested it out first by moving my pc next to the tv and using a shorter cable I already had. SAME THING (!).
So then I thought, OK I'll plug the stereo speakers directly into my pc and see what happens - music is good.
So I'm trying to figure out what the issue is here. I think I've ruled out everything other than the TV at this point, and sound is fine when the TV is playing through the speakers by itself. The TV is set to use the speakers as the audio source, which I assumed bypassed the TV. But could there be some meddling by the TV causing issues with the sound when streamed wirelessely to chromecast (connected via its own HDMI), or when PC directly plugged in (via HDMI)?
To recap, heres a diagram:
[ PC ] --- Wireless stream through Chromecast via Videostream or Plex ---> [ TV ] <- Stereo speakers
= Bad music
[ PC ] --- Connect directly via HDMI cable ---> [ TV ] <- Stereo speakers
= Bad music
[ PC ] --- Connect directly to Stereo speakers
= Good music