3143 metal box interfere with coils

[u-47]

Hi everyone!
I'm about to make an upgrade to a pair of 4343 crossovers with Mundorf parts, removed the original parts and started with the new ones placement until.... I realise that metal case interferes with the new coils!!!! No matter what kind of core (air, Iron, etc) except for the E cores, they don´t changes a damn bit!!!!!! (like the jbl originals)
Do you know why is that?
Can I just take off som turns of the new coils to reach the desired value "inside the box"?
Will this degrade the audio?
Thanks in advance

77264

[grumpy]

Place the coil further away from the box surface... the change should be minimized.
If it were on a printed circuit board, it could be inches away from the box.

Having an open magnetic circuit next to a ferrous object/surface will change the
behavior (inductance in this case). I would be reluctant to change the coil value
to accommodate the box.

[u-47]

Place the coil further away from the box surface... the change should be minimized.
If it were on a printed circuit board, it could be inches away from the box.

Having an open magnetic circuit next to a ferrous object/surface will change the
behavior (inductance in this case). I would be reluctant to change the coil value
to accommodate the box.

Is true that this phenomenon decreases with distance but the problem is that I have to place 5 coils inside the box so not only the box is the problem!
I will do my best to avoid interaction between the coils and box...not a simple task!
What keeps me wondering is why the E cores don't change with proximity, not only with the box but neither with other coils!:confused:

[Mr. Widget]

The best solution is to not use the steel box. Aluminum or plastic would not be a problem, or simply mount your board inside the speaker or even externally.


Widget

[grumpy]

Sure... but I can see wanting to maintain the original form factor/layout... at least somewhat :)

With an E-I core, the magnetic flux travels almost entirely within the core with much less potential for external coupling
vs other inductor types.

[u-47]

Mr. Grumpy nailed it!!! :applaud:
Is my wish to preserve the box.
Later I will post some images of my experience....if there is some:D
Thank you

[Mr. Widget]

Mr. Grumpy nailed it!!! :applaud:
He's pretty good at that. :D

Actually I pretty much assumed that was the case… However if you're going to go over the audiophile grade parts, I'd suggest going all the way.

Keep us posted.:bouncy:


Widget