Extron Electronics Mechanical/Loudspeaker Engineer interview questions

Submitted application via website. Received e-mail requesting Skype interview with hiring manager. This went well, so I moved on to a phone interview with HR manager in Raleigh. This one went well too, so I was invited down to Raleigh for on-site with Mech Engr. Mgr and team. Interviews went well. Technically wasn't very challenging as what they're doing acoustically isn't close to cutting edge, but everyone was nice and the atmosphere was kind of formal but reasonably relaxed. Facility has a lot of empty space, including an entire floor, because, they say, they are planning for long-term growth. Final interview was with HR manager, who asked typical HR questions, including the "quality or quantity" one. I thought everything went really well and everyone acted a little excited at the end of the interviews, but then about a week later I received a rather curt e-mail stating that they were going to continue looking. I asked for the reason(s) why (for my own edification, not to argue) but never received a response.