Inductor Placement on Xover

gtforme00

Member
2004-10-21 4:35 am
You might notice that all of the worst cases involve having coils that run parallel to each other. Even though the inductor axes may be at 90 degrees, if any of the wires are parallel there still will be coupling.

You seem to be doing all of your homework for this build, I hope you are documenting the build (at least pictures) and that you will post a thread on your progress!

Good luck with the build,
David
 
gtforme00 said:
You might notice that all of the worst cases involve having coils that run parallel to each other. Even though the inductor axes may be at 90 degrees, if any of the wires are parallel there still will be coupling.

You seem to be doing all of your homework for this build, I hope you are documenting the build (at least pictures) and that you will post a thread on your progress!

Good luck with the build,
David

Thanks, so it looks ok? BTW I'll post a thread once everything gets here :)

Brendan
 

gtforme00

Member
2004-10-21 4:35 am
Peter N,

Your inductor placement is good.

Brendan,

I'm a bit confused by your schematic. I do not see the series 0.1mH inductor on Zaph's schematic. Where did it come from? As far as the placement of the inductors go. I would try to separate the woofer and tweeter parts of the crossover (perhaps put the woofer crossover on the floor of the enclosure and tweeter crossover on the ceiling of the enclosure?) This would allow you to separate the inductors further to minimize crosstalk. As drawn, assuming the 0.1mH inductor is correctly included, I would be concerned about mutual coupling between the 0.28mH and the 0.1mH as they have parallel coil segments that are close together.

Regards,
David

EDIT: I should rephrase the "parallel coils" part of my previous comments. It is not enough to just make sure that the full coil diameters are not parallel. If segments of the coils are parallel (as with the inductors in your drawing) there will be coupling. The best case is where the inductors have no parallel segments as shown here:
[IMGHTTPDEAD]http://www.troelsgravesen.dk/coils_files/coils_5.jpg[/IMGHTTPDEAD]
 

gtforme00

Member
2004-10-21 4:35 am
I see now, it is an updated crossover for a replacement tweeter. I would put more distance between your inductors and try to make sure they cross at right angles to each other. Beware of the common error of laying an inductor flat and standing another inductor up next to it as shown in your drawing above. The fields will couple and you will have crosstalk between your tweeter and woofer circuit. If you have to keep the inductors closely spaced to fit in the enclosure, elevate the large inductor so that its central axis is lined up with the inductor that is standing up.
 

Peter N

Member
2008-02-19 1:11 pm
hello, I found a site wich explain well, also with graphics and FR how to place coils, unfortunatly is in italian
http://www.audiofanatic.it/Articoli/Bobine/Induttanze.html

http://209.85.135.104/translate_c?h...diofanatic.it/Articoli/Bobine/Induttanze.html

look here:
http://209.85.135.104/translate_c?h...ofanatic.it/Articoli/Bobine/Induttanze15.html

We saw that mount inductors located orthogonal minimizes interference but ... Yes, but there is one! To obtain the maximum inversion is necessary to comply with the maximum relative squareness with a perfect centering axis relative. One deviation to one of the lobes of emission offsets for almost the entire effort, bringing the signal captured almost at the highest level.For this reason it is better to mount inductors axially with respect to crossover, so that the axes lying on the same floor