# Binary L/C substitution box for crossover evaluation



## WSJ (Jan 6, 2014)

Real time crossover evaluation can be tedious and time consuming, however, an L/C substitution unit should address some of these issues. 

The advantage of a binary L/C substitution box is to allow the maximum number of values with a practical number of components. The design can be configured to provide HP, BP or LP 2nd order filters for evaluation in real time with REQ. The unit incorporates two capacitor sections and two inductor sections that can be configured with banana cables and additional components between sections. The capacitance range is 1 to 165 uF in 1 uF increments and the inductance range is 0.1 to 16.5 mH in 0.1 mH increments. 

Please let me know what you think and what improvements or corrections could be made. 










L/C/R substitution box schematic


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## WSJ (Jan 6, 2014)

This is the capacitor board with binary weighted values: 1, 2, 4, 8, 10, 20, 40 and 80 uF.
I used a small cut off wheel to make the slots on the board.


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## WSJ (Jan 6, 2014)

This is the inductor board with binary weighted values: .1, .2, .4, .8, 1, 2, 4 and 8 mH. 
The inductor values were adjusted by adding or removing windings.





































Due to cross coupling, I will not stack them and mount them with about 5" between the boards. The 8, 4 and 2 mH have some interaction, the 8 mH may not be use with the 4 or 2 mH. I should have found a larger box to allow more spacing. If turns out to be a problem, I have enough space to make 16" x 6" boards and mount them with some space between each board.


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## NBPk402 (Feb 21, 2012)

Looks great! So you use this for comparing crossovers?


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## WSJ (Jan 6, 2014)

ellisr63 said:


> Looks great! So you use this for comparing crossovers?


I'm using REW to evaluate drivers and crossover designs. With my L/C/R substitution box I can see the effect of the entire system in real time. Then order correct fixed L/C/R components.


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