jim wrote: > I am only doing 8 mono channels so I won't need 16 only 8. No, you need 16 since I was talking about making a bandpass from a simple low and high pass. These are individually very easy to compute and running 16 of them at audio sample rates is well within a dsPIC's capability. Of course there are lots of IIR filters you could chose from, each with different characteristics like frequency flatness in the passband, rolloff rate, phase characteristics, etc, etc. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .