I have been trying to design a 2-way active crossover, with low-pass and high-pass channels. So far I got the desired frequency response but the transient response is not up to mark.

Here is the schematic : enter image description here So here I am pulling up the input signal using a 10kOhm resistor and a 10uf cap to avoid passing DC on the left-hand side of it (towards the ground). The Lowpass channel (U1B) has a resistor so it is holding the DC offset I have been giving. But the High-pass channel has a cap - and it will block my DC offset again. My question is how shall I again pull it up and at which point exactly? I tried pulling up after C7 and before R6, just where capacitance ends I believe, but it doesn't work.

Her is the AC sweep plot: enter image description here

Her is the Transient plot @1KHz: enter image description here

I want to give 2.5V biased input to the High-pass channel using my available 5V supply.

  • \$\begingroup\$ The low pins of R6, R11 and C10 should be wired to BV. Tied also a capacitor between BV and ground ( something as ~10 uF). R20 not needed (?). \$\endgroup\$
    – Antonio51
    Commented Jun 15 at 8:58
  • \$\begingroup\$ Bias U1A through R6 with properly filtered Vcc/2 (artificial ground) or convert both stages into multiple feedback (MFB) filter topologies and bias the noninverting op-amp inputs with Vcc/2. \$\endgroup\$
    – Raonoke
    Commented Jun 15 at 16:20
  • \$\begingroup\$ U1B currently provides not only AC but also DC gain. If you don't need the DC gain put a large C in series with R11 or bias it with Vcc/2. As Antonio51 already mentioned, your artificial ground needs decent filtering. \$\endgroup\$
    – Raonoke
    Commented Jun 15 at 16:33
  • \$\begingroup\$ Anotnio51 and Raonoke , thankyou guys for your input! Seems like MFB topology has worked for me. I provide 1.25V offset in similar way as I did before and connect it to the non-inverting pin , at the output stage I put 10uF elec cap to remove DC bias...and its done! thank you again ! \$\endgroup\$
    – Sajil
    Commented Jun 15 at 18:45


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