For acoustic guitars, the resonant frequency is usually the soundboard resonant frequency. Some acoustic preamps have feedback canceling circuitry that works quite well. Another common trick is to fill the soundhole to 1) keep the sound from entering back into the guitar body and 2) deaden the...
Let’s say we like an early Dark Star, say: Grateful Dead Live at Carousel Ballroom on 1968-01-17 for example. Cursing to the Internet Archive we find the concert page for the Soundboard version we like the best: Opps, No downloads on this concert. Let’s take a closer look at the...