Due to the tree structure of the filter bank, pre-echo problems are made worse, as the combined impulse response of the two filter banks does not, and cannot, provide an optimum solution in time/frequency resolution. Additionally, the combining of the two filter banks' outputs creates aliasing problems that must be handled partially by the "aliasing compensation" stage; however, that creates excess energy to be coded in the frequency domain, thereby decreasing coding efficiency.[citation needed] COUNT 5
QSN1 What kind of structure does a filter bank have? ANS1 tree QSN2 Due to a specific kind of structure, what kind of problems are made worse? ANS2 pre-echo problems QSN3 What kind of resolution are the filter banks unable to provide an optimal solution for? ANS3 time/frequency QSN4 Combining two filter banks' outputs creates what kind of problem? ANS4 aliasing QSN5 The need to code excess energy in the frequency domain decreases what kind of efficiency? ANS5 coding