Method for generating from a coefficient domain representation ( d,D) of HOA signals a mixed spatial/coefficient domain representation ( d, w; D, W) of said HOA signals, wherein the number of said HOA signals can be variable over time in successive coefficient frames, characterised by: - separating (20, 30) a vector ( d,D) of HOA coefficient domain signals into a first vector ( d 1, D 1) of coefficient domain signals having a constant number of HOA coefficients and a second vector ( d 2, D 2) of coefficient domain signals having over time a variable number of HOA coefficients; - transforming (21, 31) said first vector ( d 1, D 1) of coefficient domain signals to a corresponding vector ( w 1, W 1) of spatial domain signals by multiplying said vector of coefficient domain signals with the inverse ( Ψ -1) of a transform matrix ( Ψ); - PCM encoding (22, 32) said vector ( w 1, W 1) of spatial domain signals so as to get a vector ( w' 1,W' 1) of PCM encoded spatial domain signals; - normalising (26, 36) said second vector ( d 2, D 2) of coefficient domain signals by a normalisation factor (1/|| Ψ || ∞), wherein said normalising is an adaptive normalisation with respect to a current value range of the HOA coefficients of said second vector ( d 2, D 2) of coefficient domain signals and in said normalising the available value range for the HOA coefficients of the vector is not exceeded, and in which normalisation a uniformly continuous transition function ( h n ( j -1)) is applied to the coefficients of said second vector ( x n ( j)), which thereafter represents a current second vector ( d' 2,D' 2), in order to continuously change the gain within that current second vector from the gain ( g n ( j -2)) in a previous second vector to the gain ( g n ( j -1)) in a following second vector, and which normalisation provides side information ( e) for a corresponding decoder-side de-normalisation; - PCM encoding (27, 37) said current second vector ( d 2, D 2) of normalised coefficient domain signals so as to get a vector ( d " 2,D " 2) of PCM encoded and normalised coefficient domain signals; - multiplexing (23, 33) said vector ( w ' 1, W ' 1) of PCM encoded spatial domain signals and said vector ( d " 2,D " 2) of PCM encoded and normalised coefficient domain signals. - separating (20, 30) a vector ( d,D) of HOA coefficient domain signals into a first vector ( d 1, D 1) of coefficient domain signals having a constant number of HOA coefficients and a second vector ( d 2, D 2) of coefficient domain signals having over time a variable number of HOA coefficients; - transforming (21, 31) said first vector ( d 1, D 1) of coefficient domain signals to a corresponding vector ( w 1, W 1) of spatial domain signals by multiplying said vector of coefficient domain signals with the inverse ( Ψ -1) of a transform matrix ( Ψ); - PCM encoding (22, 32) said vector ( w 1, W 1) of spatial domain signals so as to get a vector ( w' 1,W' 1) of PCM encoded spatial domain signals; - normalising (26, 36) said second vector ( d 2, D 2) of coefficient domain signals by a normalisation factor (1/|| Ψ || ∞), wherein said normalising is an adaptive normalisation with respect to a current value range of the HOA coefficients of said second vector ( d 2, D 2) of coefficient domain signals and in said normalising the available value range for the HOA coefficients of the vector is not exceeded, and in which normalisation a uniformly continuous transition function ( h n ( j -1)) is applied to the coefficients of said second vector ( x n ( j)), which thereafter represents a current second vector ( d' 2,D' 2), in order to continuously change the gain within that current second vector from the gain ( g n ( j -2)) in a previous second vector to the gain ( g n ( j -1)) in a following second vector, and which normalisation provides side information ( e) for a corresponding decoder-side de-normalisation; - PCM encoding (27, 37) said current second vector ( d 2, D 2) of normalised coefficient domain signals so as to get a vector ( d " 2,D " 2) of PCM encoded and normalised coefficient domain signals; - multiplexing (23, 33) said vector ( w ' 1, W ' 1) of PCM encoded spatial domain signals and said vector ( d " 2,D " 2) of PCM encoded and normalised coefficient domain signals.