Question about sound with HD files

OK ignore the content of said files, this is just a simple question of figuring out some sound issues.

First things first. When it comes to picture I am a quality-aholic. I love full HD and have recently gotten a 4k tv.
Now, a problem I have always had, on a 4k or a HD tv, is high quality video from various sources tends to have audio problems. By problems I mean a standard problem of the conversation being too quiet while the music / action is super loud.

I have always put this down to one simple thing. The audio I use tends to be the tv's built in speakers. Yeah yeah, I know I could do so much better. Now I am assuming something recorded in these situations for full HD also is 5.1. And the issue I get with tv sound is that it is only playing front left and front right equivalent channels through these. So the usual place for dialogue would be front centre, which it doesnt have, meaning we need to turn it up to get it audible.

Now, having this shiney new tv, I am eager to sort out this one nagging issue (without buying a soundbar / 5.1 setup), and hopefully in a simple permanent way. I am hoping there is some way to downscale audio automatically to 2.0 without issue, as the tv upscales HD to 4k marvellously.

TV in question:

LG 49UF850V Smart 3D 4k Ultra HD 49" LED TV
Running:
WebOS

OK.. Long winded explanation incoming.

While the quality of the TVs speakers do not help, they are not really the problem when you have speech that is much quieter than the rest of the audio. You can still get the same issue with decent stereo speakers although maybe to a lesser degree. The problem isn't so much that because you're using stereo, you're only hearing the left and right channels from a 5.1 source. If you were, you would hear no speech at all, except maybe from people to the sides or off screen. The 5.1 audio stream is mixed down to stereo, so you will get all 6 channels over stereo.

The problem at least when it comes to films with 5.1 tracks, is that the speech is lower than the main music and effects. This is still a problem many people experience even with a 5.1 speaker set up, because of the way Hollywood produces the audio tracks; so it's not like having a centre speaker immediately solves the problem. In many films, especially blockbusters, they tend to overemphasise the music and effects, to the point where the volume has to be loud in order to clearly hear the speech. For anyone who has this problem with an AV receiver, then the best way would be to increase the volume of the centre speaker in relation to the rest.

When using stereo speakers though, this can be done, but may be either tricky or impossible, depending on the set up. If you're connecting a USB device to the TV to watch films, then there's not much you can do really, because it's likely the TV will have fairly basic playback software, with nothing to alter individual track volume levels in a video file with a 5.1 track. If you're using a media player box though, for example one running Kodi, then you can increase the speech volume.

I use stereo speakers, and I used to have the same issue, with speech volume being too quiet until I turned the volume up, them boom! action sequences happen and it's too loud. I have Raspberry Pi with Kodi on it in to play media, and that has options which allow the speech in 5.1 tracks to be increased, so there is a better balance between being able to clearly hear speech, while not crazy loud volume when all hell breaks loose in an action film. It works very well.

If you don't want a separate media box, then I'm sure there's a lot you can do to get round the quiet speech problem.

TL;DR

Unless you buy a media box with Kodi or other similar media playback software that allows you to alter the speech volume within a 5.1 track, there's not much you can do about it.

Hmmm this IS good news, I have a Kodi HTPC for just such fun occasions!
I will have to go hunting through some menus!