If you send yourself a music file by e-mail check the size of the file before you send it (bit total) with the size that you get back. Your e-mail system may be reducing the size by decreasing the bit sample rate. If there is a lesser amount of data comming back it is being done automatically to speed up the transfer time. This is data compression and once data is lost it can't be recovered. If you compress the file yourself by switching from WAV to mp3 before sending you may be better able to control what is lost. Dynamic compression on the other hand will not have a significant alteration on the file size but will increase the level of lower volume and decrease the higher peaks. If the reverb is the natural acoustic echo of the room it will certainly increase with dynamic compression.