# Bandpass filter for summing amplifier input

I need to create a bandpass filter for a single input to a summing amplifier. In this example of a summing amplifier, I understand how the capacitor and resistor in series creates the low cutoff frequency of $1/(2\pi RC)$ for the individual signal. But what is the best way to create an upper cutoff frequency for an individual signal here?

I know a capacitor in parallel with the feedback resistor like this would create an upper cutoff frequency, but that would affect all input signals:

What's the best solution to this?

• Filters are usually defined by -3dB band pass and -xx dB band stop rejection levels. What would you like? Mar 27, 2017 at 20:44
• "The best way"..... Hmm... Mar 27, 2017 at 21:00
• How about "any way" lol. I just want to have a low and high frequency cut off, so each cutoff frequency is at -3 dB... Mar 27, 2017 at 21:12
• I'd use a few amps to do this. One to sum and one to do the filtering after summing. If you need different high pass poles, I would use three different amps and then one summing amp Mar 27, 2017 at 21:53
• @donut a more specific question would get you a better answer instead of leaving it open-ended. Jul 11, 2017 at 15:11