2x Feedback Destroyers 100$ Each. They are perfect for those hard-EQ rooms and eliminate feedback. You can put a microphone in front of a speaker and nothing. It Auto detects problem frequency. I used them for weddings when clueless folks would stand with a wireless mic next to a speaker :facepalm: These are 2 Channels per unit. I owned 5 of them - Downsizing to 1, doing more lighting these days. See my other listing for more Gear. The more you buy, the better deal. All my Sound Gear is Stored in Oak Bay; I live in Langford, so will have to arrange a time for sale Contact me below ;) Kendra Martin