You can scale the filter coefficients before quantizing them to ensure that all the accumulators use the same data range.

A filter structure consists of many accumulators. Each accumulator might use a different data range. However, the LabVIEW Digital Filter Design Toolkit provides only one sum quantizer QS> for all the accumulators. Scaling the filter coefficients can help you obtain a better filtering result, especially for IIR Cascaded Second-Order Sections Form structures. Use the DFD Scale Filter VI to scale the coefficients of a floating-point filter.