Crossover inductor DCR value

[vilts]

Hello,

I'm going to build my first 2 pairs (one for my friend) of ProAc 2.5 clones and one question has come up. Building crossover I'm planning to use parts from soniccraft.com site.

Now on xo design there are all inductors rated at 0.2 ohm DCR. Is it neccessary to have these DCR values as close as possible to design, or can I use inductors with other values? I found one thread, where it said that DCR can be 0.2 ohm maximum. Or do I need to have DCR as small as possible - by using all inductors with gauge 12?

For example one inductor has to be 0.25 mH (I thought I use 0.27 mH). So is it better to use inductor with biggest DCR (0.124 ohm, gauge 12) or with smallest (0.049 ohm, gauge 12).

Thanks in advance,
Viljo

 

[DirkD]

Hi there

DCR is more important on the inductors in the low pass section of the crossover. Exact values of DCR is not to important. Anything between 0.1 and 0.4 ohm on all inductors should be fine. Exact mH value is, however very important. By all means buy the 0.27mH value, but use an LCR meter to unwind to exactly 0.25mH. Alternatively you can remove 4 windings from an AIR CORED (and air cored ONLY) inductor to give you very close to 0.25mH.

Dirk

BTW what crossover are you building? After lots of experimentation I found that I preferred the Jacq modified crossover with resistor in series with the parallel capacitor (in low pass section).

 

[vilts]

Thanks for answering,

I'm going to build Troels crossover with Jacq's mods from here:
http://www.geocities.com/diyproac25/Troelsmodifiedcrossover.JPG, because it seemed to be best from comments I read.

And now I'm wondering how much costs LCR meter 🙂.

Viljo

 

[DirkD]

Check out these links. I have not built any of them, but I would imagine that it could be worth a shot.

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=LC1C

http://www.rainbowkits.com/kits/ia-1p.html

Regards

Dirk