I hold in my grubby little hand a BassEgg. It can amplify the sounds of a guqin using any surface. After trying out different materials with the Bass Egg, I realized that less dense wooden materials sound much louder and richer in bass, compared to denser wooden materials. Maybe it's because less dense wooden materials could vibrate more. Glass and concrete are the softest, as they won't vibrate much. I had inserted an Audio-Technica brand lavalier microphone deep inside the soundbox of the guqin from the larger sound hole and connected it to the Bass Egg. Check out www.BassEgg.com for more details. It ships to customers worldwide from the USA or from UK (two different warehouses). *smile*
Picture of BassEgg next to my guqin.