Hey all, I've been having a little problem with my Roland Microcube lately, and was hoping for some advice.

The amp is less than 6 months old (got it unopened straight from a store) but already its tone is sounding more and more muddy. I play metal more than anything, and have noticed ( and yes this will sound ironic) that the distortion is sounding worse and worse. Also, its fuzzing out the lower notes more than it used to.

As for the cause, I am not 100% sure. It hasn't been in any water, and its adapter is working fine when plugged in (i regularly change the batterys too). The only thing I can think of that is different from when I got it is that my lower tuned guitar (Randy Rhoads) is strung with Ernie Ball Not Even Slinkies (12's) which tend to sound a lot more like bass strings than guitar when tuned to drop C.

If anyone here knows what might be the issue, and possibly can offer some advice or warnings, I would be very appreciative. Thank you for reading.
don't know if you blew the little speaker out of the poor thing or what haha

Otherwise, check cables, do you use a guitar with active pickups? Any effects that could be the problem? Try a different guitar...make sure it is the amp first, then go from there
Randall RM100/Basson Cab
DBX166XL/BBE Sonic Maximizer
Boss NS-2, sCream Cheese 2.0 OD, Zakk Wylde wah
Custom Epiphones
Monster Cables
Awe-in-One picks..and more
my other guitar is a xiphos in standard tuning with Dimarzio deactivateds, it sounds better than the rhoads ( which has jackson stock pickups) but unfortunately sounds relatively worse than it used to. Unfortunately, Roland makes microcubes so you can't open them up and tinker without destroying the casing.
The same thing happened with my Cube 30. I don't know what it was exactly but I imagine it might be the speaker.