Method for and apparatus for decoding/rendering an Ambisonics audio soundfield representation for audio playback using 2D setups

A method of determining a decode matrix ({tilde over (D)}) for decoding an encoded audio signal, the encoded audio signal being in Ambisonics format for L loudspeakers, the method comprising:

• determining a set of loudspeaker positions comprising at least one virtual loudspeaker position ({circumflex over (Ω)}′L+1) and the positions ({circumflex over (Ω)}1, . . . , {circumflex over (Ω)}L) of the L loudspeakers;
• determining a first matrix (D′) having coefficients for the positions of the set of loudspeaker positions;
• and
• determining the decode matrix ({tilde over (D)}) from the first matrix (D′), at least by weighting and distributing the coefficient(s) for the at least one virtual loudspeaker position of the first matrix (D′) to coefficients relating to the positions ({circumflex over (Ω)}1, . . . , {circumflex over (Ω)}L) of the L loudspeakers, whereby the decode matrix ({tilde over (D)}) has coefficients for the positions ({circumflex over (Ω)}1, . . . , {circumflex over (Ω)}L) of the L loudspeakers,
• wherein said weighting and distributing the coefficient(s) for the at least one virtual loudspeaker position of the first matrix (D′) comprises weighting said coefficient(s) with a
• weighting
• ⁢
• ⁢
• factor
• ⁢
• =
• 1
• L
• .