The first thing you have to realize when amplifying an acoustic guitar is that in doing so you’ve gone interactive, which sounds very nice except that it happens to work against you in this situation. What do I mean by “interactive?” Just that your acoustic guitar interacts with its sonic environment, and when that environment gets loud, acoustic guitars get weird.
In this video, reviewer Justin Horenstein demos the Roland AC-40. This is a compact acoustic amp that’s super lightweight at less than 12 lbs. It has dual 6.5 inch speakers for stereo and a tilt stand to angle the amp upwards. The amp has two channels, each with their own independent EQ, reverb, and chorus controls. Channel 1 has a dedicated GUITAR input, and Channel 2 has a MIC/LINE input for another acoustic guitar or mic for vocals.