Échelle diagrams of the oscillation spectrum of model 1 obtained using the JWKB approximation, and assuming different coupling intensities between the g-mode cavities (q₁ = 10⁻³, 10⁻², 10⁻¹from left to right panels). The size of the symbols indicates the expected height of each mode. For clarity, only the modes with a height corresponding to at least 10% of the height of a pure p mode are shown. Modes colored in red have at least 50% of their total energy trapped in the innermost g₁ cavity (i.e., I_g1/I > 0.5). Top panels: frequency échelle diagrams folded with the large separation of acoustic modes Δν. Bottom panels: stretched period échelle diagrams built following Mosser et al. (2015, see text).