they suffer from distortion due to the non-linear shape at high excursion. they have a documented problem in both the L5 and L7 line with lead-slap and separation. I've seen a number of them with blown coils, mostly due to amplifiers being improperly adjusted. I'm not a big fan of the subs at all myself.. they're also rather ugly.
set it up properly, and there will be no problems. if you are looking at L7's then you aren't looking for a pure SQ sub anyway, applying common sense always helps out.
OR you can take everyone else's opinion and buy an eD, RE, or Adire sub because they are the best subs EVER :rolls eyes:
I guess you'll just see what we're talking about when that RE MT rolls over your L7s in SPL, or the Solo X for that matter. Or we could just bust out the Adire Parthenon motor, if we can find a cone that would accomodate the 12" of peak to peak excursion.
oh hell, my RE triple x subs would beat a solo-X no problem. that solo-x is a crap heap. I've seen several unravel their voice coils within an hour of purchase. Lovely products there.. lovely.
another major drawback to a square sub nobody mentioned is that since the sub is square, and due to how the surround has to accomodate that shape, it severely limits the excursion of the driver, so while surface area increases, the Xmax is cut way down. This means essentially you gain nothing by the increased surface area of the cone, and in fact probably lose some in total displacement of air next to a good round high excursion sub, like the RE subs that Chief is so fond of bashing.