I have an Audioque Hdc-312 that is dual 2 ohm. I have owned it for about a year, but I only tried it out for a few weeks. I put it in a sealed box I already had and soon realized I can't give up the trunk space to put this in a proper ported box. There isn't a mark on it, you can't tell it's not new except for tiny smudges on the rubber gasket where I put screws through. I'm new here but I've been on diyma for a couple years.