Hi lak
I have the upgrade model Hemisphere break in is long. Right out of the case it sounded good. But with about 10 to 15 hours on it it got dark and a little smaller sounding closed in. (The sound was still very clean sounding) I am not sure exactly about the 50 hour mark it started to open up again slowly got better. I felt it was going in spurts of changing for the better then level off some for a while then increase for the better. I have a little over 100 hours on mine and its still changing. When i talked to Rick he told me the MC O6 Hemisphere was very different than the MC O6 not only upgrade plugs but trickle down technology from their top of line conditioner. I not know if this answered your question. You might try contacting Rick at HF he is good at responding to questions good luck.
Enjoy Pete
I have the upgrade model Hemisphere break in is long. Right out of the case it sounded good. But with about 10 to 15 hours on it it got dark and a little smaller sounding closed in. (The sound was still very clean sounding) I am not sure exactly about the 50 hour mark it started to open up again slowly got better. I felt it was going in spurts of changing for the better then level off some for a while then increase for the better. I have a little over 100 hours on mine and its still changing. When i talked to Rick he told me the MC O6 Hemisphere was very different than the MC O6 not only upgrade plugs but trickle down technology from their top of line conditioner. I not know if this answered your question. You might try contacting Rick at HF he is good at responding to questions good luck.
Enjoy Pete