Melt-spun ribbons of Co₆₄Fe₄Ni₂B_19−xSi₈Cr₃Al_x (x=0, 1 and 2) alloy at wheel speed of 25 m/s and Co₆₄Fe₄Ni₂B_19−xSi₈Cr₃Al₁ alloy at different wheel speeds (25, 30, 35 and 40 m/s) have been prepared and investigated for structural and magnetic properties and magnetoimpedance effect. Based on the results obtained, it was shown that replacement of B by Al can improve the magnetoimpedance ratio (MIR) and the highest value of MIR (191%) was observed for the sample with X_Al=1 at wheel speed of 25 m/s. Further, it was seen that the higher quenching wheel speed gives rise to a higher coercivity and lower magnetic permeability/MIR value.