ˌɔn ðɛɹ lˈɑːɹdʒ sˈɪvəl tˈɜːbɑːfənz, ɹˈoʊlzɹˈɔɪs splˈɪt ðə kəmpɹˈɛʃən sˈɪstəm ˌɪntʊ θɹˈiː: ɐ fˈæn, ɐn ˌɪntɚmˈiːdiətpɹˈɛʃɚ ˌaɪpˈiː kəmpɹˈɛsɚ ænd ɐn ˌeɪtʃpˈiː kəmpɹˈɛsɚ, ˈiːtʃ jˈuːnɪt bˌiːɪŋ dɹˈɪvən baɪ ɪts ˈoʊn tˈɜːbaɪn jˈuːnɪt.
On their large civil turbofans, Rolls-Royce split the compression system into three: a fan, an intermediate-pressure (IP) compressor and an HP compressor, each unit being driven by its own turbine unit.