Non-contact and long-range acoustic or multi-modal sensing in air can be employed for a number of industrial, IoT, biomedical, and remote-sensing applications but requires the use of resonant, highly sensitive ultrasonic receivers to achieve sufficient SNR. Fabrication of such resonant MEMS sensors fundamentally trades off bandwidth for sensitivity, thus limiting resolution in these sensing systems. In this paper, we devise an all-electronic means of dynamically tuning the sensitivity and bandwidth of high quality factor sensors by using a nested phase modulation scheme that simultaneously achieves high bandwidth and high SNR. We demonstrate an >8x increase in bandwidth in ultrasonic ranging and non-contact photoacoustic measurements, while concurrently boosting the SNR by up to 13x with potential for further enhancement.