Do you get the same sound in your headphones when connected to the same source that drives the monitors....if yes then its not the monitors. As Loren said change the cables or change the monitors if you have some older ones around.
Also look to all the sample rates between various device...I have a feeling it could be something get restricted. I have had issues with devices not communicating correctly that has created similar problems easily resolved.
Is this brittle distortion coming from just one or both monitors...you say one but you show both in the video
It is a real pain and frustrating because you have to do all this detective work...pull everything apart and re-patch it all and pull some hair out and maybe send it out for repairs when it could be a simple thing you over look or did not know you needed to even look....I have done just this.
Hoping for a simple fix!
The DAC sounds normal with headphones. I have also tried the different monitor outputs, and also switched right and left cable, still it is only the left monitor that sounds bad.
If it was the sample rate, it would audible in both right and left channel.
The the brittle distortion comes only from one speaker the left.
Yes it is really painful.. I hope that PMI/Trident care for their customers though, I am unable to find any information regarding warranty.
Since I do not want to void possible warranty I do not want to open up them, also I do not want to do that since I am not a certified technicians, I will most likely need to send these to a service center. Luckily I bought them from a swedish dealer maybe they will pay all the costs I hope so..