A sophisticated coupled-channel analysis is presented that combines different processes: the channels {pi ^0pi ^0eta }, {pi ^0eta eta } and {K^+K^-pi ^0} from {{bar{p}}p} annihilations, the P- and D-wave amplitudes of the pi eta and pi eta ^prime systems produced in pi ^-p scattering, and data from {pi pi }-scattering reactions. Hence our analysis combines the data sets used in two independent previous analyses published by the Crystal Barrel experiment and by the JPAC group. Based on the new insights from these studies, this paper aims at a better understanding of the spin-exotic pi _1 resonances in the light-meson sector. By utilizing the K-matrix approach and realizing the analyticity via Chew-Mandelstam functions the amplitude of the spin-exotic wave can be well described by a single pi _1 pole for both systems, pi eta and pi eta ^prime . The mass and the width of the pi _1-pole are measured to be (1623 , pm , 47 , ^{+24}_{-75}), mathrm {MeV/}c^2 and (455 , pm 88 , ^{+144}_{-175}), mathrm {MeV}.