TV's Frink said:

Do you know which version you watched? The original only had stereo sound but he did an updated version with 5.1. I saw the stereo one and have had the 5.1 version on my HDD waiting for a watch for a while now.

It was the updated release with the 5.1 audio.

Transformers: Age of Extinction (2014)

Now that was definitely more like it! A quantum leap above the dreck that was RotF. Michael Bay actually delivered a great movie about transforming robots. All of the idiocy from the previous entries was nowhere to be found. Optimus was still a little too edgy but overall it was a breath of fresh air compared to the others. I'm actually really looking forward to the sequel.