the present invention relates to a new method and apparatus for improvement of high frequency reconstruction techniques using frequency translation or folding or a combination thereof . the proposed invention is applicable to audio source coding systems , and offers significantly reduced computational complexity . this is accomplished by means of frequency translation or folding in the subband domain , preferably integrated with spectral envelope adjustment in the same domain . the concept of dissonance guard - band filtering is further presented . the proposed invention offers a low - complexity , intermediate quality hfr method useful in speech and natural audio coding applications .