Honestly i dont know why jamo put the c4 series in the concert line, it should be in the s 5 6 7 line as s8 or something.
Now that is taking things too far..!! Have you heard them before?
I have heard the C605 and S8 while I purchased (and also E series).
S8 was pure junk. (period)
S406 was a disgrace (I hope you do not think this is the one I have).
C405 and C407 only passed the bass I wanted with the midrange I wanted.
Others did not have the bass I wanted.
C605 and C607 traded bass for midrange. They had their own list of short comings. If your speakers were anywhere related to these, they dont have the bass. But I haven't heard them so, no comments.
Now, Why would you compare the C405 to S8. grrr.