One US forum stated a while ago that there was a difference in the LEs and Premium sound kHz and:
"So basically the code difference is the EQ sampling for the difference in kHz. After all the upgrades the frequency was taken from 20hz to 12 kHz. The LE's are gonna POUND."
I also vaguely recollect Steve saying a while back that they were going to do some additional LED lighting code for the LEs over the Premiums.