Which, Foil Air Core or Iron Core Inductors

[umut1001]

hi..i have 0,5mh air core inductors..my multimeter is broken and i dont know how much resistance they have..do you have an idea..it has about 3cm radius and 3cm height..thanks

[badman]

Originally posted by umut1001
hi..i have 0,5mh air core inductors..my multimeter is broken and i dont know how much resistance they have..do you have an idea..it has about 3cm radius and 3cm height..thanks

The guess would be about .4 ohms, but is highly dependent upon wire gauge.

[tinitus]

I agree with most of it

About coil resistance I thought it would only matter on bass
Which means it will also matter on a 2way and 2.5way,
in some cases even a higher resistance may be preferred
Only on a pure midrange it wont matter

[umut1001]

http://cgi.ebay.com/Copper-Foil-Air-...rkparms=66%3A2|65%3A15|39%3A1|240%3A1318

its same but i have 0.5 mh inductor..i think its 0.075ohm..its very low isnt it ?

[thoriated]

From what I've read, the laminated steel core inductors tend to have the least distortion of the saturable core types.

I generally like the foil types, but the insulating tape dielectric properties become more important than for round wire types. I once did an xover with early Solo inductors using mylar instead of polypropylene tape and replaced them later with Goertz types because of the improved (less harsh) sonic properties of polypropylene.

Foil type inductors generally have two advantages over round wire types: less skin effect, meaning the inductance is more constant to higher frequencies (more important for HF applications where skin effect is more noticeable as a coloration in the sound) and they don't 'sing' like most round wire inductors do, due to their very solid mechanical construction. Of course, this can largely be minimized for round wire inductors by potting them, but many of them do not come that way, so I've taken to using 'Hot' CA to basically glue the windings together before installing round wire inductors.

[thoriated]

I generally like the foil types, but the insulating tape dielectric properties become more important than for round wire types.

This is because layer wound round wire inductors have about 20% air volume within their windings and foil wound inductors don't. That's a good thing for round wire inductor SQ, too because the best commonly used magnet wire enamel from a SQ perspective is a form of polyester.

[Gioxtream]

Dear friend. While trying to upgrade my speaker crossovers.I trashed by mistake a pair of original air coil inductors.

I know how important is DCR on the original crossover network.Here are the values:

Mid-range coil:


0.418 mH
0.6 ohms
0.8 mm diameter


Tweeter coil:


0.228 mH
0.4 ohms
0.8 mm diameter

I know these are the correct values.A friend measure them for me.
Could you please help me find the coils to match my speakers.I miss them so much.Your help would be appreciated.
I forgot to mention ....that i found a web page that have some coils.

Here:

Jantzen Inductors - Core Round Wire


Let me know what you think. Thanks in advance.

Originally Posted by sdclc126

Foil inductors are considered a waste of money, period. Solid core inductors are usually recommended for inductances higher than 2-3 mH and in high power applications, usually in bass circuits for 3-way or subwoofer systems. The only thing to consider is DCR and how it will affect the rest of the system.

IMHO in your particular application go with standard air core and save your money. That would be my choice and you won't hear any difference.