looks like there is a phase shift between l_a from the sound horizon and l_peak from the the TT spectrum. see equation A7. http://iopscience.iop.org/0004-637X/549/2/669/pdf/0004-637X_549_2_669.pdf
Thanks for the detailed answer. I have the following question. I'd like to know if the horizon you mentioned is the same as sound sound horizon (c_sound*time_recombination)? As I can see from this table l_a = 301...