ɪn pɚtˈɪkjʊlɚ, splˈɪt ɹˈeɪdɪks ɪz ɐ vˈɛɹiənt ʌvðə kˈuːli tˈuːki ˌɛfˌɛftˈiː ˈælɡɚɹˌɪθəm ðæt jˈuːzᵻz ɐ blˈɛnd ʌv ɹˈædɪsᵻz tˈuː ænd fˈoːɹ: ɪt ɹᵻkˈɜːsɪvli ɛkspɹˈɛsᵻz ɐ dˌiːˌɛftˈiː ʌv lˈɛŋθ ˈɛn ɪn tˈɜːmz ʌv wˈʌn smˈɔːlɚ dˌiːˌɛftˈiː ʌv lˈɛŋθ ˈɛn slˈæʃ tˈuː ænd tˈuː smˈɔːlɚ dˌiːˌɛftˈiːz ʌv lˈɛŋθ ˈɛn slˈæʃ fˈoːɹ.
In particular, split radix is a variant of the Cooley–Tukey FFT algorithm that uses a blend of radices 2 and 4: it recursively expresses a DFT of length N in terms of one smaller DFT of length N/2 and two smaller DFTs of length N/4.