Hi!
I'm starting to learn Pd Extended and I trying to make a filter able to highpass, lowpass, both things or neither of them, but I'm having problems making a toggle to bypass the filters:
While in the highpass filter everything works fine (I can move the slider to the frequency I want, I can turn it off and I can turn it on again keeping the frequency I chose before), when I try to do the same on the lowpass filter, everytime I turn the toggle off (as a bypass), I stop hearing the sound.
Here is my configuration and my patch:

problem.pd

Thank you in advice!

1. You should use Pd vanilla + needed externals. Pd-extended is not maintained anymore, which means that should you encounter bugs with it (and there are), they won't be corrected, like, ever.

2. This is not how you bypass a filter. Remember that toggles can take 2 values, 0 and another one (typically 1) when clicked. Your slider sends a float to the atom, which sends the float to the toggle, which hands it to the [hip~], which understands the float as a frequency value to set the filter. When you click the toggle, it sends a zero, which sets the hi-pass filter to zero hertz and thus gives the wrong impression that it's bypassed when actually you just set it to its lower value. Eventually, this trick doesn't work with [lop~], because a low-pass filter set at zero hertz acts almost like a mute button.

3. Then, how to bypass signal object ? You have to come out with a way to make the signal go to your filter OR to the next object.

See this example of how to do this. This is only one way to do, there are many : bypass-example.pd

PS : i was very intrigued by this behaviour of [tgl] that would alternate between zero and the last non-zero value that went through. I remembered seeing this a long time ago... Eventually, this behaviour was ditched with 0.46 but we still have a compatibility mode. Another reason to let Pd-extended go, i guess !