diff --git a/src/effective_waves/wavemode.jl b/src/effective_waves/wavemode.jl
index a6489ae..544a21c 100644
--- a/src/effective_waves/wavemode.jl
+++ b/src/effective_waves/wavemode.jl
@@ -57,7 +57,7 @@ end
 function WaveMode(ω::T, wavenumber::Complex{T}, psource::PlaneSource{T,Dim,1}, material::Material{Halfspace{T,Dim}};
     tol::T = 1e-6, kws...) where {T,Dim}
 
-    direction = transmission_direction(wavenumber, (ω / material.microstructure.medium.c) * psource.direction, material.shape.normal)
+    direction = transmission_direction(wavenumber, (ω / psource.medium.c) * psource.direction, material.shape.normal)
     eigvectors = eigenvectors(ω, wavenumber, psource, material; direction_eff = direction, kws...)
 
     α = solve_boundary_condition(ω, wavenumber, eigvectors, psource, material; kws...)
diff --git a/src/wave_types.jl b/src/wave_types.jl
index 1ae5aaa..457b011 100644
--- a/src/wave_types.jl
+++ b/src/wave_types.jl
@@ -100,8 +100,6 @@ struct  EffectiveRegularWaveMode{T<:AbstractFloat,P<:PhysicalMedium,S<:AbstractS
         if typeof(medium_material) != typeof(medium_source)
             if (typeof(material.shape) <: Sphere{T, 2} where T) && (typeof(source.medium) <: Acoustic{T, 2} where T)
                 S = TranslationSymmetry{3, Float64}([0.0, 0.0, 1.0])
-            else
-                throw(DimensionMismatch("dimensions of acoustic medium of material $medium_material and source $medium_source do not match."))
             end
         else
             S = Symmetry(source,material)