Is there a filter that removes the differences between two tracks or channels?
I know this is what usually happens with “balance filters” where the two signals are 180 degrees apart from one another, and anything that isn’t a perfect mirror of the other gets filtered out.
I have two channels and I’d like to filter out the differences between the two channels similar to how a balance or differential signal filter works.
Maybe the [u]Vocal Reduction and Isolation[/u].
Thanks for that suggestion. Unfortunately, it seems this effect adds really bad artifacts to the audio. Everything sounds buzzy as if there is a second sample playing a few ms after the first sample.
I’m not sure exactly what you are after, but perhaps the “Channel Mixer” plug-in: https://wiki.audacityteam.org/wiki/Nyquist_Effect_Plug-ins#Channel_Mixer
I’m simply looking for a differential filter. One that filters any signal that’s not in both channels.
To make it simple, let’s say I have two channels, both have a 120hz sine wave in them, but one channel also has a 200hz sine wave in it. I want a filter that will make sure that when I sum both channels, all I get is the 120hz sine wave.
The idea being, I could record two channels of audio, (one inverted if needed), and then filter out any noise introduced during the capture process, similar to how balanced signalling works, except done in software instead of electronically.
The idea being, I could record two channels of audio, (one inverted if needed), and then filter out any noise introduced during the capture process, similar to how balanced signalling works, except done in software instead of electronically.
Subtraction (like the center-channel vocal remover) can work perfectly… And that can be done electronically or digitally.
Unfortunately for what you’re trying to do, summing (like normal stereo-to-mono) includes everything. You can also do that electronically or digitally.
There is no “simple math” for keeping what’s identical in left & right while and removing what’s different. Except if there is a sound that’s identical but out-of-phase in both channels. In that case it will be removed when you mix to mono. Sometimes that happens accidently with “amateur” recordings. If the vocals are out-of-phase the vocals are lost when it’s played-back on a mono phone speaker,
Or, under “laboratory conditions” you can sometimes subtract-out sounds. For example, If you have a vocal and instrumental track and you mix them together, you can invert the vocals and mix again to cancel the vocals. Or, you can do the same thing to cancel the instrumentals. But in that case you usually have both original-separate tracks already.
I understand what you’re saying, but that’s not what I’m trying to do.
I’m not trying to do summing, I’m trying to do masking. What isn’t exactly the same in both channels, doesn’t make it through to the output.
To be clear, the vocal isolation tool that was first suggested with the centre isolation function is exactly what I want to do, BUT it’s introducing interfearnce that isn’t normally there in the signal.
I understand what you’re saying too, and it doesn’t work perfectly 
Ah, well that’s too bad. I just realized Adobe Audition does it pretty well, and I own a copy too, so I’ll just leverage that.
Thanks for the help.
What is the effect called in Audition?