Imagine you have a synth bass line that’s a combination of a sine and a saw wave instrument. You like the vibe, but when you turn them both up you aren’t feeling the fatness. That’s likely because the low frequencies of the combined signal are suffering from destructive interference. The fact is, since the housing bubble burst in 2008, easy credit has been difficult to come by. Banks are very skittish about lending to people who may ultimately not be able to pay back their loans, a big reason the bubble burst in the first place.