Testing Crossovers w/ unknown component values

THUMP LUMP · 16th August 2007, 02:59 PM

I have a number of older Rockford Fosgate car stereo crossovers that look to have good, not great, components in them (air core inductors and poly caps). Without ripping these all apart to see what the values are, is there any way to test them to see what their crossover points are? Some of the caps I can see but, their is nothing on the inductors. I was thinking a series of sine waves and loading them with a 4ohm resistor and measuring the voltage at the resistor. I am clueless if this would work or if there would be a better alternative.

Thanks in advance, Ken

richie00boy · 16th August 2007, 03:21 PM

They will be designed for specific speakers. Just rip them apart and use the parts in something else. You can work out the inductances with a sine wave and a load resistor.

acid_k2 · 16th August 2007, 03:31 PM

hi THUMP LUMP

You could:

0- search crossovers datasheet, or

1- buy un inductance meter (or a DMM with inductance meter), measure inductors and calcolate frequency, or

2- Buy a sinusoidal generator, a frequency meter, a linear amp, a resistive load and observe attenuation of voltage on the load...

IMMO, if you want to know the value of inductance for re-using inductors, method 1 is the best...

acid_k2 · 16th August 2007, 03:41 PM

If you have a PC with amplified soundcard, you can use some program (search with google) to create a sinusoidal tone. You may find (in the same way) a frequency-meter for soundcard.

16th August 2007, 02:59 PM	#1
THUMP LUMP diyAudio Member Join Date: Aug 2007 Location: Arden,NC	Testing Crossovers w/ unknown component values I have a number of older Rockford Fosgate car stereo crossovers that look to have good, not great, components in them (air core inductors and poly caps). Without ripping these all apart to see what the values are, is there any way to test them to see what their crossover points are? Some of the caps I can see but, their is nothing on the inductors. I was thinking a series of sine waves and loading them with a 4ohm resistor and measuring the voltage at the resistor. I am clueless if this would work or if there would be a better alternative. Thanks in advance, Ken

16th August 2007, 03:21 PM	#2
richie00boy Did it Himself diyAudio Member Join Date: Nov 2003 Location: Gloucestershire, England, UK	They will be designed for specific speakers. Just rip them apart and use the parts in something else. You can work out the inductances with a sine wave and a load resistor. __________________ www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more

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16th August 2007, 03:31 PM	#3
acid_k2 diyAudio Member Join Date: Oct 2006	hi THUMP LUMP You could: 0- search crossovers datasheet, or 1- buy un inductance meter (or a DMM with inductance meter), measure inductors and calcolate frequency, or 2- Buy a sinusoidal generator, a frequency meter, a linear amp, a resistive load and observe attenuation of voltage on the load... IMMO, if you want to know the value of inductance for re-using inductors, method 1 is the best...

16th August 2007, 03:41 PM	#4
acid_k2 diyAudio Member Join Date: Oct 2006	If you have a PC with amplified soundcard, you can use some program (search with google) to create a sinusoidal tone. You may find (in the same way) a frequency-meter for soundcard.

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