In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. The Blue Cab 20 is a big-sounding and flexible bass combo amp in a very small package. Perfect for the lesson room, backstage green room or bedroom, the Blue Cab 20 is very easy to use while still giving you professional-quality tone and performance. A super-efficient 10-inch speaker coupled with a ported cabinet and a tilt-back feature allows you to maximize the 20 watts of power and project the tone where you need it the most. Best of all, the Blue Cab offers you all of these great features at an incredibly affordable price.