I was not happy with the speakers of Octavia III, and had them replaced some time ago with a Focal 6.5" speaker set.   However, I'm still not satisfied with the sound. The tweeter sounds like some frequencies are coming from a vague direction causing some kind of small but annoying distortion. I can't think of any other reason but the speaker grill to cause this issue. Since replacing the grill with custom mounting cups is quite tedious, I'd love to hear if someone has similar experien