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Iron core vs air core inductors

qu-be-2

Wammer
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Dec 16, 2008
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Jaedon
Is there any value in swapping out the iron core inductor in the bass section of my crossover for an equivalent air core? I understand that air cores are generally favourable but also read that the distortion produced by the driver will be greater than that from any iron cored inductor in the circuit :dunno: . Seems to be a fair bit of conflicting information on the web.

 

hearingisbelieving

Wammer
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May 10, 2011
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Chris
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  1. No
IMO you will get much more sonic improvements from replacing the caps in your crossover than the inductors or resistors (assuming you havent already). Sorry i cant help with your actual question though

 

Valvebloke

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Dec 3, 2009
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  1. No
The devil is in the detail. Iron is imperfect - it is magnetically nonlinear and if you push it too hard that nonlinearity will start to show. But copper wire is imperfect too - it is resistive when all you want an inductor to be is, well, inductive. With no iron you typically need a great deal more wire and unless you beef up its cross-sectional area enormously its resistance can become significant. In the end you find that you can make either kind of inductor work if you're prepared to make it physically large (=heavy and expensive) enough.

VB

 

qu-be-2

Wammer
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Dec 16, 2008
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Jaedon
Yeah, the caps are all chunky polyprops :^ . It's just the inductor in the bass section is the original bargain basement iron core jobbie that was there when the 'speakers were still Gale model 4's. The rest of the crossover has been completely redesigned, but that one component is bugging me. The woofers are only cheap though, so I'm kinda thinkin' it doesn't matter.... maybe....

 

qu-be-2

Wammer
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Dec 16, 2008
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Jaedon
I have my eye on some wax foil inductors which are reasonably priced (ish). I only need 0.75mH so shouldn't be too mahoosive I wouldn't think?!

 

speedysteve

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Dec 25, 2007
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Stig Forsberg
Just look for the lowest DC res when browsing air cores - the price goes up the lower.

I got mine from http://www.audio-components.co.uk/store/category.asp?CategoryID=2

(no connection with them other than satisfied customer).

0.75 is not that big :) - Best air cores there are £15 a pop and should do the job fine.

The waxy ones look very nice and are about double that.

I cheated on the big ones I needed for my 90Hz crossover and got C-cores. 24mH! They worked fine. I needed 320uF caps (from memory) and they cost more I think!

 

MF 1000

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Apr 5, 2011
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  1. No
The best large Mh c cores I've used are the

janzen torrid ones... V low resistance

 

killie99

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Jul 12, 2011
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  1. No
I bought mine from http://www.europe-audio.com/ , about half the price of Audio Components although you need to add shipping. I was buying 1.4 and 1.6mm x-section Jantzen air coils so they weren't cheap but even with the shipping costs they were miles cheaper.

 

speedysteve

Wammer
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Dec 25, 2007
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Stig Forsberg
Yep, I had to get Janzen to make my 24mH ones - they only go to 20mH stock.

The best large Mh c cores I've used are the janzen torrid ones... V low resistance
- - - Updated - - -

That's good to know, but I am firmly in the DSP camp now - so much easier if change drivers impedance / X/O points :)

I bought mine from http://www.europe-audio.com/ , about half the price of Audio Components although you need to add shipping. I was buying 1.4 and 1.6mm x-section Jantzen air coils so they weren't cheap but even with the shipping costs they were miles cheaper.
 

Beobloke

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Jul 29, 2005
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  1. No
Stick with iron cores for the bass and save the air-cores for the midrange and treble.

 

awkwardbydesign

Perfect, apparently.
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Mar 5, 2012
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HiFi Trade?
  1. No
I bought mine from http://www.europe-audio.com/ , about half the price of Audio Components although you need to add shipping. I was buying 1.4 and 1.6mm x-section Jantzen air coils so they weren't cheap but even with the shipping costs they were miles cheaper.
If you ask John at Audio Components, he may match Europe Audio's price. He did with all the parts for my Troels Gravesen build.

 

qu-be-2

Wammer
Wammer
Dec 16, 2008
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Salford, UK
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Jaedon
Thanks for all the replies. I went ahead and ordered 2 of the Jantzen wax foils from audio-components. Unfortunately my hand slipped as I was ordering and I accidentally bought 2 shiny new Morel tweeters as well :shock: . Just waiting on the coils now as the tweeters arrived t'other day and are already fitted and integrated nicely. Such fun! :D