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3TD-X Inductor Crosstalk Testing

I bet you couldn't find any of those "sometimes it doesn't help" builds with data to actually prove such a claim. Reducing secondary cabinet related sound sources is always beneficial. There's tons of evidence out there showing improvements with round overs, which lines up with all my own data and listening impressions. I already made a pretty long post here about it citing tons of examples and how basically in every single speaker generating HF information, round overs/chamfers/etc are of benefit.

I'll look later. But the gist of it was that if you have a crossover already optimized for a speaker (exact non-coincident drivers + cabinet) for a target X-axis response, and you change the baffle by adding a big roundover, that X-axis response might change in ways that are detrimental to the original goals.

So, upon reflection of my comment, I take back what I said and think that you are correct; a roundover will make a difference (assuming that the drivers can even "see" the edge). It just might not always be a desirable difference.
 
It would be very easy to tilt the 400uH orthogonal to the 750uH (which is several inches away on other side of the board). That way, each inductor would be orthogonal on the [x,y,z] axes. Super-easy modification. I potted mine using epoxy so my crossover is "literally stuck".

There is a 3.0 mH inductor between them that is already at 90 degrees. Tilting one of the ones on the ends would necessitate flipping all of them, which is no different than it is now.
 
Ok, here's my take on this whole issue. We already know that inductors will act as a transformer and pass signal in this way. I'm a bit surprised at how far apart the affect is still happening but overall I think this is getting blown out of proportion in terms of any impact.

First, in a parallel filter network, the entire signal is being passed to each driver. The components are working to filter that out, but the signal is always there, just at reduced levels. Second, if it was an issue, you would see additional distortion or frequency response anomalies, i.e. if I measure the drivers with no components, model the impact of those components, and then measure the speaker with those components attached, it would not match the model if there was an issue and we would likely see additional distortion components as well.

The real issue comes from inductive coupling, which can cause actual changes in the value of the inductor and will definitely impact the frequency response. The simplest way to test if there is going to be an impact is to measure with the inductors far apart and then keep moving them closer together until you see a change. That is how far apart they have to be.

I will also say that these inductors are already about 8" apart with another inductor at 90 degrees between them. To move them further apart you would need to split the boards and on some more complex crossovers you would have to basically start placing components all over the the inside of the cabinet to stay further away. No company on the market (even those with massive engineering budgets) does this because they aren't seeing impacts in frequency response and it's not practical.
 
I think this is getting blown out of proportion in terms of any impact.



No company on the market (even those with massive engineering budgets) does this because they aren't seeing impacts in frequency response and it's not practical.
Yeah, my hope has been that it doesn't matter in practice, at least not for existing circuits in decent speakers.

I think I'll still experiment with different layouts just for fun (unless someone else beats me to it, as I don't have a good testing setup even close to ready).
 
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