Bandpass with large group delay
This depends a lot on whether your constraints on the number of taps is computation or memory.
If you have a enough memory, you can simply use an FIR with all taps zero except for the last one (Which is $1$). That's equivalent to using a ring buffer and no filter at all.
If you don't have enough memeory, things are more tricky. YOu can get delays that are constant with frequency with parallel/cascaded alpass filters and you can use &quot;schroeder allpass&quot; filters to crank up the group delay effificently. The best way to do this depends a lot on your specific constraints: how much memory do you have, how wide is your frequency range and how &quot;constant&quot; does that delay needs to be.