I spent a torid time yesterday turning a working XO into a non working one. I wanted to alter various values and so had the thing on the bench and plenty of desoldering old and replacing new components in. And I somehow made a mistake. So spent rest of the day trying to fault find. I had no sound out of it....just some kind of feint music from the tweeter. Desoldered pretty much all I had done to be able to see all the traces clearly. Turns out I had a broken track on the ground circuit.
I have REW and DATS V3 and was assuming given greater knowledge how to use this gear I could maybe test an XO to see what's happening without having to keep pluggin it back into the speaker and amp?
I have REW and DATS V3 and was assuming given greater knowledge how to use this gear I could maybe test an XO to see what's happening without having to keep pluggin it back into the speaker and amp?
A lot could be said for using a multimeter. I mean sure, you could probe to detect signals at various parts of the circuit but what probably helps most is the method you use to eliminate parts of the circuit and zone in on the problem.
Ah yes I think I overlooked the obvious there didn't I.! Although I am aware I don't always understand the results one gets when testing for continuity/resistance where capacitors are involved. But here on a ground track I would have been ok!
Indeed.
There are times you can measure without removing components and times you have to lift a leg. For example, a multimeter can place a Voltage over a capacitor simply because you measured resistance, and that Voltage will mess up future measurements.
Resistance measurements may be preferred, especially when you're not sure whether running the amp will cause damage and don't want to apply a signal. Measuring across the input terminals of the crossover might tell if there's a short at low frequencies, but can't measure a short at high frequencies (through a capacitor). Therefore it can be better to break it down to checking tracks and components.
When checking tracks, don't only check for open tracks, also check for different tracks being accidentally shorted.
There are times you can measure without removing components and times you have to lift a leg. For example, a multimeter can place a Voltage over a capacitor simply because you measured resistance, and that Voltage will mess up future measurements.
Resistance measurements may be preferred, especially when you're not sure whether running the amp will cause damage and don't want to apply a signal. Measuring across the input terminals of the crossover might tell if there's a short at low frequencies, but can't measure a short at high frequencies (through a capacitor). Therefore it can be better to break it down to checking tracks and components.
When checking tracks, don't only check for open tracks, also check for different tracks being accidentally shorted.
Thanks Allen. I think I was blinded by assuming there was a short between the signal and ground somewhere and overlooked an open one which would have been easier to find, maybe! I did meter across the inputs and I think it was open. But I didn't know what to do with that information!
