MoFi 888 making me mad!

I had this experience back in the mid 90s. I traded in a pair of Definitive Technology BP2000 speakers on a pair of Von Schweikert VR4 Silvers. After a couple of days I called the dealer to ask if I could get my old speakers back. No luck, already sold. So I just left the VR4s in the basement listening room playing 24/7 for almost a month. What I came back to was astonishing. I kept them for three years, which is the equivalent of half a lifetime when it comes to me and speakers.

Last year I bought a demo pair of Grado headphones from a local dealer and according to him, they only had about 10 hours on them and would need a minimum of 50 hours to break in. (They did and then some). I asked him why they had so few hours on them. He said they try to turn over the demo stock fairly quickly and most of the gear is sold far before the normal break in period. He kind of said that if it’s in the shop and fully broken in, it’s a sales dog. 
 

Anyway, my point is that your speakers probably weren’t nearly broken in when you got them. 

Any speakers I've ever bought have needed between 100 and 200 hours of playing time to sound like they should. I would doubt that a dealer's demo pair would have had anything close to that. 

@larsman 

Yeah, apparently not.

traudio, I've been in this hobby for decades so have gone through multiple new speakers.  The break in time among those varied, but it was minor with the SP-888s I bought new last year.  They were not demos bu in factory sealed boxes.

The break in was very slight, nothing like you described.  Mainly a tightening of the bass and a bit of solidifying the detail and imagining.  Change was slight and seemed to have settled in after 30 hours or so.  In fact early on friends who heard the speakers remarked on the excellent sonics, including bass.  I'm very pleased with mine.