- Made version of each spectrum filter prepended with a voltage follower (buffer), then made a file with buffed filters connected to the same signal, another with all the non-buffed filters connected to the same signal, and finally one with both versions connected to equivalent signals
- Then I compared their input impedances (measured between Vsig and ground)
- The one with input buffers (green) had an input impedance of [28Mohms : 1.213Gohms]
- The one with no input buffers (red) had an input impedance of [6kohms : 20 kohms ]
- This was measured over the audio range - 20Hz : 20kHz
- Compared the difference of the outputs of each spectrum filter
- The differences grew from ~40uV (Sub-bass filter) to ~7.4mV (Presence filter), this is way less than I expected
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