æt hˈaɪ ˌoʊvɚɹˈɔːl pɹˈɛʃɚ ɹˈeɪʃɪˌoʊz, ðə kəmpɹˈɛʃən sˈɪstəm ɪz jˈuːʒuːəli splˈɪt ˌɪntʊ tˈuː jˈuːnɪts; ɐ lˈoʊpɹˈɛʃɚ ˌɛlpˈiː kəmpɹˈɛsɚ mˈaʊntᵻd ˌɔn wˈʌn ʃˈæft fˈɑːloʊd baɪ ɐ hˈaɪpɹˈɛʃɚ ˌeɪtʃpˈiː kəmpɹˈɛsɚ mˈaʊntᵻd ɔnðɪ ˌeɪtʃpˈiː ʃˈæft ænd dɹˈɪvən baɪ ɪts ˈoʊn ˌeɪtʃpˈiː tˈɜːbaɪn.
At high overall pressure ratios, the compression system is usually split into two units; a low-pressure (LP) compressor mounted on one shaft followed by a high-pressure (HP) compressor mounted on the HP shaft and driven by its own (HP) turbine.