A friend reached out to me recently looking for some advice on a small, portable sound system to use for his duo of acoustic guitar and the puerto rican cuatro.
One of the instruments had a pickup and the other a microphone was used. In addition to a speaker needed close to their performance area, an additional speaker was needed to cover another room in the restaurant.
Knowing ease of use, affordability and portability were high on the list, I suggested the following. I hope this can help you, too!