Ring resonators offer the opportunity to tailor the effects of nonlinear processes in such a way that photon pairs can be generated into separable narrowband biphoton states. To vary the properties of these generated photons, one can spectrally filter the output modes, however, these losses reduce the heralding efficiencies and coincidence-to-accidentals ratios. Instead, one can vary the spectral response of the resonators. One method to achive this is to couple the resonator to the bus via an unbalanced inteferometer (UMZI), thus allowing the effective coupling constant to vary over different frequencies. We will explore this process by varying both the unbalance \(\Delta L\) between the arms of the interferomter, as wel as the length of the ring. The resulting transmittion spectra will then be used to infer the potential for pure heralded photon generation using these devices.