Merging is slow while merging 2 audio files

[yasir0899]

@ZeroOneZeroR
I tried to merge 2 audio file one of duration was 33:00 minutes and 2nd one duration was 27:00 minutes.
Merging was done, but it takes 20 min to merge these 2 files after merging the size of the files was 42 MB.
can you ;look into it why it takes so much time for merging?can you make it fast ?

[sammi06]

I also used this faced same issue.... 7 minutes audio + 10sec audio took 10 minutes to complete