This paper describes the Mixed Multi-Band Excitation coder used for a low bit-rate speech coding. In MBE coders, there are significant differences of the fine structure between the original and the synthetic spectrum. They are mainly due to the exclusive partition of voiced and unvoiced regions in frequency domain and the decision procedure based on the experimental threshold. The MMBE uses frequency domain mixture function (FDMF) to overcome these drawbacks of the MBE coder. Also, two analysis methods, which do not need any decision procedure based on a threshold, are presented. The performance evaluation results show that the 2.6kbps MMBE coder reduces the average spectral distortion by a clear margin comparing to the 2.9kbps MBE coder. The computational load of the proposed coder is sufficiently small for a real-time implementation on the modern DSP chip.