This study examined the acoustic characteristics of American English liquids /ɹ/, /l/, and /ɹl/ produced by 14 adult learners of English (L2) and 13 native speakers of English. Several temporal and spectral measures were examined, including a novel measure to describe the relative timing of the maximum constriction during liquid production. The results indicated that L2 speakers rely more on duration contrasts to distinguish the three liquids than spectral contrasts. Reduced spectral differences among the liquids in L2 speakers are discussed concerning the influence of the native language of L2 speakers.