Under saddle pickups are easy to install but they don't always sound as good as they could. Often response is inconsistent from string to string, output can be low overall. Even pressure over the entire length of the bridge saddle is the key to getting even response from string to string. Often a factory installed system is not thoroughly checked for performance before delivery to stores and customers. There are some basic things that can be done to make under saddle piezo-electric pickups perform at their best, and there are some tricks and tweaks that can be used to overcome variations in the base and sides of the saddle slot and/or the actual saddle.
If you are not happy with how your nylon string or acoustic under saddle system sounds bring it in and we can check it out. There could be a quick fix or there could be more complicated issues at play. We always consult before going ahead with any more complicated or time consuming repair or modification, assessments are free!