One of the most frequent issues and criticisms regarding the sound of our flat screen televisions has to do with movies and the lack of clarity in their dialogue. It doesn’t matter if you give it more or less volume, the voices of the actors are always with a lower sound level than the rest of the effects and the soundtrack, which makes it difficult to understand.

The normal thing in these cases is to think that it is a defect of our TV and its tiny speakers, but the truth is that this is not always the case and it is probably a problem with part of the media player that we use to watch the movie and which is responsible for transforming the multichannel content into stereo.

The multichannel conversion matrix

So, for example, the rest of the classic programs such as news broadcasts, contests, cartoons, series and other content that is originally recorded in stereo offer better intelligibility of the dialogue without having to turn the volume up. maximum.

I don’t mean to say that they are heard with higher sound quality because the specifications of the built-in speakers are the same. Simply that they are not masked by sound effects and music allowing the voices of the actors to be heard without problem.

What does it talk about? Well, there are a number of reasons, but the most common is that converting multi-channel sound (e.g. 5.1, 7.1, or Dolby Atmos) to two-channel stereo isn’t done properly or as many of us would like. , favoring the central channel (where the dialogues reside) over the rest.

This is a typical resource problem. We have two sound channels with limited capacity through which we have to pass 5.1, 7.1 or more channels, reducing the power of each of them so that they all fit without distortion. Here we can choose from countless weighting options for each channel giving priority to the different possible configurations thanks to the so-called multichannel conversion matrix.

This is a question that we can essentially represent by a matrix in which in its columns we find the original channels (for example for a 5.1 system: right, center, left, rear right, rear left and subwoofer ) and in its rows the stereo channels (right and left) to which we will direct the first.

To do this, the amount of each input channel that will go to each output channel must be weighted with a coefficient or a percentage, something that has several approximations. This matrix is ​​found in the software or hardware of equipment (televisions, multimedia players, decoders, consoles, Blu-ray players, etc.) and each manufacturer decides how to implement it.

Original matrix of 5.1 input channels and 5.1 output channels Before buying a TV under $ 500, take a look! – PERFECT TV FEATURES

Infinite options to configure the matrix

It may be that a compromise solution is chosen in which all the levels of the surround channels and the subwoofer are reduced but still keeping the center channel above with a higher coefficient than the rest, which will give us a good result in movies. without much effect.

You can also keep all the channels at the same level which will undoubtedly make us have very low volume dialogue and effects and always top music, but it will work well in music type content like concerts and concerts. live shows.

5.1ch to 2ch conversion matrix

Another option, and in my opinion the one that works best with cinema, is to eliminate the rear effects channels from the mix and even the subwoofer, as the TV speakers are not prepared for frequencies. handled by the bass channel and the only thing we do if we incorporate it into the set is add distortion.

This way the conversion is much more balanced and the vocals will always be above or at a similar level to the rest of the music and main effects.

If the matrix is ​​poorly handled by the TNT channel, you will probably have to turn the volume down and up during the whole movie

Very good, but how can I experience the possibilities of this matrix for myself? Well, it is difficult, especially if the mixture is beyond our reach. For example, it is usual that if we watch movies via TNT, the matrix has been managed in the external player that broadcasts the programming (that is, in the network or the TV channel), so in these case, we will not be able to do anything Even if we buy the best soundbar, since the center channel has already been “originally damaged” by the channel we are tuning to.

And here there are stations that do it well and others in which you have to pull the remote control to raise and lower the volume all the time during the movie, no matter how good your television is or even if we have a good home. movie theater .

Another way to modify this matrix is ​​to change the configuration fields of many televisions that manufacturers refer to as “listening modes” and that, in addition to other things like equalization, these proportions tend to vary, although ‘they don’t let us play with specific values.

But if you have a computer and want to thoroughly test the possibilities it offers, I recommend you install the AC3 filter and try it with an MPC-HC type media player. This filter allows us to play with the matrix and choose which channels we want as a priority and which we prefer to leave out. This is the best option I know of if we are using a PC as the player connected to the TV, achieving great results even with low powered speakers.