Crossover phase help

All the op amps seem to be non inverting unity gain buffers with various filtering around them so all the outputs should be in phase together already.

Why don't you simulate it and check with LTSpice or similar

Yes, all Sallen-Key filters. More info and equations here:

http://en.wikipedia.org/wiki/Sallen%E2%80%93Key_topology

All right, I must admit that I´ve never seen some of those topographies, eg the single pole active. Interesting, but what you have are the basic 2-pole version. All in phase.




Edited by Earplug - 25 April 2015 at 12:51pm

I use it quite a bit, what do you want to know exactly? There are a lot of good tutorials on the web but that goes without saying.

Op amp filters can be inverting or non inverting depending on how you implement them. Inverting buffers tend to be preferred if you need a gain less than unity but then you have to be more careful about phase of course.

Now here is a fun thing about LTspice - you can use as your input actual .wav music files. The simulation takes a long time even on a fast PC so I only tend to process about 20s of a track but you can put real audio files into your filter designs and then listen to them afterwards when they have been processed. That's pretty cool.

Here is a video I made sometime ago showing the differences in Crossover Slopes versus Phase.

It may give you an idea on what to expect at 12 dB per octave.



Best Regards,


Edited by Elliot Thompson - 25 April 2015 at 7:12pm