To attach microphones to actors heads that are using the mikes during the entire show, use spirit gum. This is only a good idea to do if the microphone element is large, otherwise bobby pins work. If you are switching mikes during the show, it is best from my experience to just clip them or re bobby pin them. Depending on how well your sound system is set up, most feedback in any one space with similar microphones will be on the same frequencies. On a mackie with a sweepable EQ, you will want to cut out almost everything between the ten o'clock and one o'clock position (I can't remember the frequencies). I happen to use a SR32-4. Anyway, you will want at least a 24 band EQ (unless you already have one) between the main board and the amps. Give yourself some feedback that you normally get, and then try cutting out frequencies on the EQ untill the feedback goes away. Do this as many times as you need.
If you could take pictures of all your gear and post them, it would allow us better to tell you what you will need to do. If your wireless packs have a screen with a level indicator on them, make sure that that level is not peaking with normal use. If if is, it is a problem with your pack.
If you could take pictures of all your gear and post them, it would allow us better to tell you what you will need to do. If your wireless packs have a screen with a level indicator on them, make sure that that level is not peaking with normal use. If if is, it is a problem with your pack.