For a long time now, I've been concerned your speakers don't play ultrasonic properly. I had a pair before, that only JUST had distortion/static when playing ultrasonic. Like they were just barely on the cusp of outright extreme racket while playing ultrasonic and the test file. I literally had to be right up against them almost to hear the static/distortion. I switched them to be safe, as it was clear they were not reliable anymore for listening. They worked for SM4G, and E2, even earlier versions of DMSI. But apparently not for DMSI 3.1.
I recommend doing a speaker test of the speaker test file http://www.subliminal-shop.com/product/speaker-test/, and listen with your ear right against the speaker at a very good volume when listening to the ultrasonic. Try to hear ANY distortion/static.
Regardless of the results, I'd give another set of speakers a month of use instead, to rule it out to be positive. I've mentioned this before, but I thought I would do so again as it seemed to have been glossed over and I don't think any changes were made. This may help, it may be a speaker issue all along.
I recommend doing a speaker test of the speaker test file http://www.subliminal-shop.com/product/speaker-test/, and listen with your ear right against the speaker at a very good volume when listening to the ultrasonic. Try to hear ANY distortion/static.
Regardless of the results, I'd give another set of speakers a month of use instead, to rule it out to be positive. I've mentioned this before, but I thought I would do so again as it seemed to have been glossed over and I don't think any changes were made. This may help, it may be a speaker issue all along.