Diagnosing inadequate bass in an audio system.

If you feel you have inadequate bass output from your audio system -

1) How do you confirm/quantify your suspicion aka what you think you hear as a problem?

2) How do you go about diagnosing the source of the problem, and how best to fix it?

Assume a CD source, DAC, preamp, power amplifier and floor-standing speakers.

Thanks,

Amit