What is the test for admitting evidence that is irrelevant, inadmissible or hearsay?

A trial court has broad discretion in determining relevancy, but it cannot admit evidence that is irrelevant or inadmissible under constitutional or state law. (People v. Morrison (2004) 34 Cal.4th 698, 724.) "The proponent of proffered testimony has the burden of establishing its relevance, and if the testimony is comprised of hearsay, the foundational requirements for its admissibility under an exception to the hearsay rule. [Citations.] Evidence is properly excluded when the proponent fails to make an adequate offer of proof regarding the relevance or admissibility of the evidence. [Citations.]" (Ibid.; Evid. Code, 1200, subd. (b).)