crossover help for Troel's Ellam

DIFORCE

Member
2009-05-02 9:24 pm
I'm buildint Troel's Ellam with the scanspeak 9800 alu dome tweeter and I have a few questions , Does it matter If I use copper foil or air core inductors ?
does thier AWG matter ? In the tweeter path there is a 20 AWG 0.15mH inductor , What if I change that to lets say Goertz cooper foil 16 AWG ? Is that OK and are better inductors make a diffrence ?

Basically im asking if I could put any AWG coil be it foil or not as long as i keep the intended mH value ...
 
Wire's resistance is determined by : length; area section ;metal used .
When a crossover filter is being elaborated ,currents that will flow in each component are calculated too .If a woofer absorbs 10 A (pulses only !) the resistance of the coil (the low-pass one/ones) will be part of its performance . Tweeters are a little bit more fragile than woofers . Remember that often when specified , the resistance(and then ,the sectional area) of the coil is fundamental for a correct funktioning of the crossover circuit .
Changes just for style or worse ,for neglecting basic electronics ,are bad.
 

DIFORCE

Member
2009-05-02 9:24 pm
sorry Didn't quite get what you were saying , So I cant change the type of inducter and thier size ?

Does that mean that air core 20 AWG valued 0.5mH will be different then copper foil 14 AWG that is also valued 0.5mH ? Are they not the same if in the end they are both 0.5mH ?

So it IS critical to keep the size and type of the inducter ( and obviously mH value ) the same as in the original plan ?

problem is those madisound inductors look cheap ( https://www.madisound.com/store/index.php?cPath=404_20_26 ) and I dont want it to hurt the performance of the expensive scanspeak drivers ...
 
sorry Didn't quite get what you were saying , So I cant change the type of inducter and thier size ?

Does that mean that air core 20 AWG valued 0.5mH will be different then copper foil 14 AWG that is also valued 0.5mH ? Are they not the same if in the end they are both 0.5mH ?

So it IS critical to keep the size and type of the inducter ( and obviously mH value ) the same as in the original plan ?

problem is those madisound inductors look cheap ( https://www.madisound.com/store/index.php?cPath=404_20_26 ) and I dont want it to hurt the performance of the expensive scanspeak drivers ...
I'm not looking at the xover in question. But inductors have parameters like capacitive, inductive and resistive. If you go with the inductive param. like you said and the resistive param. you will be very much inside spec. Usually changing gauge/diameter of a wire changes resistive value.
 

nicoch58

Member
2004-10-06 12:20 pm
I have the ellam, very nice sound

the r1031 is the resistor of coils 0,2 ohm need near this , but not so much problem for the tw, I use a solen liz here....

All clarity caps , and kiwane for the tw a lot better the mox resistor, you can try mills too , in the and your taste...

for l2021 no problem as he have in series a real 1ohm resistor , the most important is the l2011 0.3ohm as in series with woofer..

best
 
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"Basically im asking if I could put any AWG coil be it foil or not as long as i keep the intended mH value ... "

As long as you use the correct values you'll be OK. Foil inductors are VERY pricey and will not make an audible difference in your speakers. This subject is one of endless debate but many very competent speaker designers won't touch "boutique" crossover components and consider them a big waste of money.
 

nicoch58

Member
2004-10-06 12:20 pm
hummm sorry but with quality scanspeak you must use good part!! all is important...

thinks how many $$ burn on cable and how many meter of wire are in the choke!!:p better use ofc copper here....or at last decent copper !

choke shake , flat copper are better , put the filter out
 
Diforce, there are two things you need to keep the same, the inductance value, and the DC resistance of the inductor (This is shown as a white resistor in Troel's xover schematic). AWG effects the DC Resistance. The DC resistance doesn't need to be exact, but get it as close as you can.
For a small inductor of this size, it should be possible to get something close without spending unnecessary $ on 'boutique' components.
 

nicoch58

Member
2004-10-06 12:20 pm
DIFORCE

you can ask suggestion at Troels is very nice man, with a lot of experience ...

the woofer choke is big and need to be low resistence for correct dumping factor ,the small but beast woofer need to be free:p:p
the tweeter is very sweet and respond very well at caps and resistor mod ....
 

DIFORCE

Member
2009-05-02 9:24 pm
I did ask TROEL also , Problem is he keeps directing me to Janzen audio ( his sponser ) for all my XOVER needs , problem is the pay is in EURO and im not gonna order the crossovers from poland and then the drivers from madisound USA.

He also said keep the DCR at +\-0.1 OHM , I found out this is not possible with some values .

For instance a 2.2 copper foil from Goertz had 0.522 and I need 0.34 ... And the Goertz one is the closest one to the 0.32 ... others are way off . is that critical ?

most other ones are withen 0.25 +\- of ohm value needed .
all copper foil , figured might as well get the best and let the placebo effect torment me later :) hehe.