Copper foil inductors

[Rajiv]

Hi,

I am in the process of geting inductors made for my Altec Duplex drivers.

I found a person who is capable of winding air core foil inductors,but it looks like they will wind up costing a packet.

Has anyone used the foil inductors in their crossovers?


Goertz CF4.7 (12 AWG) Copper Foil Inductor

Need members views/ experiences on the foil inductors before I blow a packet.



I was quoted Rs.500+ a kilo for copper wire.

Regards
Rajiv

 

[anilva]

Hi,

I am in the process of geting inductors made for my Altec Duplex drivers.

I found a person who is capable of winding air core foil inductors,but it looks like they will wind up costing a packet.

Has anyone used the foil inductors in their crossovers?


Goertz CF4.7 (12 AWG) Copper Foil Inductor

Need members views/ experiences on the foil inductors before I blow a packet.



I was quoted Rs.500+ a kilo for copper wire.

Regards
Rajiv

Supposed to have outstanding quality and very low leakage losses. The price of 500/- per KG may be worth it.

 

[Rajiv]

Hi,

@Anil,thanks,just the kind of encouragement I need to go ahead with this.

The person said that he will give me a final costing in a couple of days.

I need two 2.5 mh, and two 4.6 mh inductors with less than 1.1 ohm dcr.

Have to hunt for the oil capacitors now.

Regards
Rajiv

 

[anilva]

Ebay has quite a number oil capacitors listed....

 

[captrajesh]

Are these for passive crossovers Rajiv what's ur take on active crossovers?

 

[captrajesh]

Are those for passive crossovers? What is ur take no active crossovers?

 

[crisscross]

Hey Rajiv! I need a few inductors as well. Can you share the contacts of your supplier? Maybe we can do a joint buy? I need a couple of 2.5mh inductors with DCR of 0.36

 

[odyssey]

Rajiv
you can try Pm'ing surrealistix on this forum. He got some Inductors made recently of around 2.2 mH with a DCR of less than 0.3 ohms. Unless you are designing for loss, isnt 1.1 ohms too high?

cheers

 

[reignofchaos]

Goertz is superb if their cables is anything to go by. Used the Goertz Alphacore speaker cables with the same copper for over two years and I'm very happy with them.

 

[Rajiv]

Hi,

Ebay has quite a number oil capacitors listed....

My first option is to scout out the local shops for NOS oil caps,failing which I will get the Russian oil caps on ebay.

Are those for passive crossovers? What is ur take no active crossovers?

Yes Capt.they are for passive crossovers.

Active crossovers are very good I like them a lot. I use a custom designed (for the Monitor Gold) active crossover with my Tannoys and it is a big improvement over the stock passive crossover.

Hey Rajiv! I need a few inductors as well. Can you share the contacts of your supplier? Maybe we can do a joint buy? I need a couple of 2.5mh inductors with DCR of 0.36

@crisscross,lets see how my inductors work out before placing an order with the supplier.

Rajiv
you can try Pm'ing surrealistix on this forum. He got some Inductors made recently of around 2.2 mH with a DCR of less than 0.3 ohms. Unless you are designing for loss, isnt 1.1 ohms too high?

@odyssey,thanks will contact him.The crossover design calls for the inductor DCR to be less than 10% of the voice coil DCR(the speakers are 16 ohm)1.1 ohm is the maximum allowed, less is better.


Regards
Rajiv

 

[GeorgeO]

Personally I havent used foil inductors-because of the higher prices from Solen ( have used their Perfect Lay wire wound inductors so far in most of my crossovers),Yes as Anil said they are supposedly better, but after reading the link below, I wonder if they are really that much better.

For more on CFC Vs WWC read this:

Copper Foil inductors versus conventional wire inductors

 

[GeorgeO]

Here's a good primer on inductors from Bob Stout who used to moderate the basslist when it was around in its original form:

LDSG AppendixE: Inductors

 

[anilva]

Here's a good primer on inductors from Bob Stout who used to moderate the basslist when it was around in its original form:

LDSG Appendix*E: Inductors

Mention of basslist brings back fond memories. I used to have my mail box full of basslist mails preserved for reference someday. In fact I have them printed on a high speed line printer (Laser Printers were a rarity then) and have them even today.

 

[GeorgeO]

Yes indeed..

I served my apprenticeship there for over 6-7 years in speaker building. There were so many helpful and knowledgeable individuals( Bob Stout, Lou Lung, Steve Katz, Mike McCall, John Janowitz, Bill Poletti, Mike Thompson, Nick McKinney and so many others) who taught me a lot not only about speakers, sub woofers and amps.The new diyspeaker forum is but a pale shadow of it's former self. In fact Mike McCall had a company Shamrock Audio, and he had a special limited time offer where he offered the design of his flagship speaker system, the Eires to basslist members who wanted to build it-I took advantage of it and built my Eire system which I have been enjoying for all of the past 7-8 years.

 

[anilva]

Yes indeed..

I served my apprenticeship there for over 6-7 years in speaker building. There were so many helpful and knowledgeable individuals( Bob Stout, Lou Lung, Steve Katz, Mike McCall, John Janowitz, Bill Poletti, Mike Thompson, Nick McKinney and so many others) who taught me a lot not only about speakers, sub woofers and amps.The new diyspeaker forum is but a pale shadow of it's former self. In fact Mike McCall had a company Shamrock Audio, and he had a special limited time offer where he offered the design of his flagship speaker system, the Eires to basslist members who wanted to build it-I took advantage of it and built my Eire system which I have been enjoying for all of the past 7-8 years.

I do remember Lou Lung, John Janowitz and Shamrock ofcourse. I did not have the means to afford or import then.

 

[GeorgeO]

BTW , Rajiv, what happened to your inductors? Did they come through?

 

[Rajiv]

BTW , Rajiv, what happened to your inductors? Did they come through?

@George,I was out of town, got back today.Will spend next week following up on the inductors.

Will post once they are done.

Rajiv

 

[Rajiv]

Hi,

The copper required to make two 4.6Mh and two 2.5Mh inductors is working out to nearly 6.5 kgs. using 14 gauge foil.The copper cost alone is nearly Rs.3500/-

Winding and other charges will add another Rs.1500-Rs.2000/-

The cost of the inductors will be nearly Rs.5000/- Having second thoughts now,since the capacitors (oil) and Mills resistors will cost an equal amount.

Total cost nearly Rs.10,000/-

Seriously considering an active crossover, or have to skimp on the caps and resistors.:sad:


Regards
Rajiv

 

[GeorgeO]

Rajiv

In comparison( just did it out of curiosity) to the appx $115 cost (Rs 5K) if bought from the US (Madisound)-excluding shipping etc) would cost $41 and $ 63 each or $104 a pair, so actually it is less than 50% of the cost. Add shipping and it will probably come to closer to 35% of US cost. Of course the Goertz quality may be better. Solen is $ 31 and $43 each.

George

 

[crisscross]

Rajiv: can you share the contacts of your supplier? Thanks!