Summary: A direct adaptive regulation scheme using an adaptive FIR Youla-Kučera filter has been proposed for solving the EJC Benchmark on rejection of multiple unknown and time-varying narrow-band disturbances[A. Castellanos Silva et al., ibid. 19, No. 4, 326–336 (2013; Zbl 1293.93439)]. Despite excellent results, this approach requires a careful design of the central controller in terms of selection of some of the assigned closed-loop poles. A modified scheme is proposed in this paper which will incorporate a particular adaptive IIR Youla-Kučera filter, called \(\rho\)-notch structure (the denominator is a projection inside the unit circle of the poles of the model of the disturbance which has roots on the unit circle). The adaptive scheme estimates separately the numerator and denominator parameters of the IIR Youla-Kučera Filter. Stability and convergence proofs are given along with simulation and real-time results. Comparison with results already obtained for the EJC Benchmark is provided. The use of this approach drastically simplifies the design of the central controller and provides even better results than [loc. cit.] with the advantage to use a single central controller independent of the number of narrow band disturbances.