People who have them like them. But then again, people also like all the filters and ground devices they place in their systems. QBase is not a filter from what I read. Just saying.
I was at the Pacific Audio Festival. There was a company pitching a RF device you placed on gear. The salesman was very leading. I told him why I found it to sound "Audiophile", not better. I actually liked it better without. He got mad and walked away.
What worries me about some of these devices is why do they have such a large, audible affect on a well tuned and well powered system. And its usually a very dark background. But did you also loose something to get the lower noise level. A natural stereo and a noiseless, high resolution stereo are very different.
