I heard the same rattle (they only had about 25 hrs on then at the time) and it will go away after break in from what I was told. A friend had them and he likes very loud and when I asked if the rattle still happened he said no. His amp was the Aavik U300. Another thing is I don't know how long it takes for the rattle to go away.
As I stated early in this thread I went to a private demo for the MB-1 - 2.5 and 3.5. They all had about 25 hrs on them and my first impression wasn't all that favorable - very boomy. Then I heard the 2.5's at approx 250 hrs and to me they sounded like totally different speakers. So much better. I owned the D2's so I didn't pay too much attention other that I thought they are a great value for the money especially after being broken in. Like the Raidho's placement is pretty critical. Ideally you want at least 9 ft apart and toed in pointing to your shoulders. Being bottom ported they can be placed pretty close to the side and back walls but I preferred them a couple feet away. IMO they are more of a near field speaker. That said with a pair of 4 1/2" drivers they are not concert level speakers.
As I stated early in this thread I went to a private demo for the MB-1 - 2.5 and 3.5. They all had about 25 hrs on them and my first impression wasn't all that favorable - very boomy. Then I heard the 2.5's at approx 250 hrs and to me they sounded like totally different speakers. So much better. I owned the D2's so I didn't pay too much attention other that I thought they are a great value for the money especially after being broken in. Like the Raidho's placement is pretty critical. Ideally you want at least 9 ft apart and toed in pointing to your shoulders. Being bottom ported they can be placed pretty close to the side and back walls but I preferred them a couple feet away. IMO they are more of a near field speaker. That said with a pair of 4 1/2" drivers they are not concert level speakers.