air core or copper foil

[crackyflipside]

Are they interchangeable assuming they have the same specs?

If not, does it matter more when dealing with the higher frequencies or do the differences occur in the whole range of frequencies?

Is this topic a can of worms?

[Amphiprion]

A standard air core inductor wound with appropriate wire gauge will be fine for any kind of passive loudspeaker crossover. There is no reason to go to foil inductors.

[Jed]

A standard air core inductor wound with appropriate wire gauge will be fine for any kind of passive loudspeaker crossover. There is no reason to go to foil inductors.

The only reason I'd get a foil air core is if I needed a 12 gauge in the woofer circuit in order to lower DCR and keep the positive qualities of air core over an iron core inductor.

[---k---]

foil air coils are reportedly a pain in the butt to work with.

[norcad]

Are they interchangeable assuming they have the same specs?

If not, does it matter more when dealing with the higher frequencies or do the differences occur in the whole range of frequencies?

Is this topic a can of worms?

If both inductance and DCR are the same, there would be no differense.
And like Jed says, its just one good reason to use foil coils, and that is if you need low DCR in a LP XO

[TacoD]

For low DCR LP applications you can also look at coils with a laminated steel core. The more expensive stuff has very low DCR, coupled with low distortion. The Mundorf/ Jantzen cores saturates at high peak loads ( 2 kW).

[Jed]

For low DCR LP applications you can also look at coils with a laminated steel core. The more expensive stuff has very low DCR, coupled with low distortion. The Mundorf/ Jantzen cores saturates at high peak loads ( 2 kW).

Taco,

Didn't JonMarsh test some of those iron core inductors and note the performance wasn't as good as is led to be believed?

[TacoD]

Taco,

Didn't JonMarsh test some of those iron core inductors and note the performance wasn't as good as is led to be believed?

I do not know, I only saw something about foil inductors.

In the last couple of editions of the HobbyHifi, a lot of coils where tested. The bigger E-core stuff only saturated on very high power levels. For this they used a PA amplifier with more power than ever needed. Even the smaller cores where already very good performers.

Recently I swapped the air core inductor with 0.5 ohm DCR in my current project LP with an 0.1 ohm DCR core inductor and I've to admit that changes are noticeable. For values > 4.7 mH I was already using core inductors.

I use the 96 core version.

http://www.mundorf.com/deutsch%201.1/Broschuere%20Einzelseiten/MCoil%20Trafokern.pdf