Absolutely agree with comments so far. I have a pair of 5.3's that I got with about 200 hrs on them by the estimate of the previous owner who is a friend. They sounded like they were really holding back and very compressed. So much so that I was thinking I'd made a mistake for the first couple of weeks I had them. Then gradually they started to sound better and better. I'd say the 500 hr mark is a good estimate where they've plateaued. As said, be patient, and keep the music playing as much as possible. It is worth the wait. These are great speakers with plenty of range and clarity and a very natural presentation. Soundstage is very impressive as well. I think a whole lot of people give up on them early as I see ads for newish examples quite frequently. Stick it out!
Marco
Marco