The pattern of the dryness in the leaves doesn't seem to match sun burn, tho. This is a Guzmania hybrid, and of the common bromeliads, Guzmania can be much more finicky than neoregelia, aechmea, or vriesea. Too much water, they rot. Too little water, they pucker & pout. Not enough light, they get leggy, too much light... etc, etc.
If I had to guess, I'd say this is moisture related (more specifically, lack of it). In regards to the soil, sounds like you are doing ok there - don't let it stay wet, but don't let it get totally dry, either. Wet soil is a death sentence. Moist to slightly dry is probably best for indoors - and if in doubt, err on the dryer side. More importantly, as Alice & Ken have said, always keep a little water within the "cups" of the leaves (where each of the leaves attaches to the stem). This is where the bromeliad absorbs most of its nutrients.
I have a Guzmania at my office that gets no direct sunlight, and is only under fluorescent lights all day. I keep its soil slightly moist to mostly dry, and just make sure there is always a little water in at least the lowest leaf cups. It's been happy and healthy for a couple of months now.
