Basic language-inherent tempo cannot be isolated by the current metrics of speech rhythm. Here we propose the number of syllables per intonation unit as an appropriate measure, also for large-scale comparisons between languages. Applying it to an extended sample of in the meantime 51 languages has not only corroborated our previously reported negative cross-linguistic correlation of this metric with syllable complexity, but has revealed, moreover, significant correlations with several in part directly time-dependent rhythm measures proposed by other authors. We discuss relations between intrinsic tempo and (a) other facets of rhythm and (b) rhythm classifications of language.