My Laney sounds like mud...especially when in small spaces

[Fassa Albrecht]

I really don't know what to do with my amp. It's my main practice amp ever since my actual practice amp broke, and yet my tone is horrible. Doesn't matter where I practice, or volume or anything under my control, it sounds muddy and in general, absolutely horrible.

Now I've used this amp at church and in large rooms and I sound fine, and yet no amount of fiddling with the EQ or tone switches seems to fix the problem when I move into small rooms such as my practice room.

Any help? My amp is a Laney RB4.