Been a while. Been busy, and it's the season ya know.
I do a LOT of troubleshooting. Not for me, for customers, potential customers, and just people with trouble. Seems like about 90% of it is crossovers. Hooking up, checking, building, everything. So here's a little primer on checking one out.
Isolate every component of the speaker and test individually first. Music or preferably a tone generator and test the speakers. Make sure they're working properly. For tweeters and mids do it at pretty low power for sure with music. If you use a tone generator to stay in their frequency range you can give them a bit more. I use SigJenny, it's easy and fast. Does all you need for troubleshooting.
Once you know the drivers are fine, start plugging in the xover to one driver at a time, and repeat the test. If it's a three way, woofer first, then mid, then tweeter. Once again the tone generator is best, because you can really hear the xover doing it's job. An analog xover is not perfect, so you will hear some sound outside the filtered passband, but it should be very far down compared to the actual passband. As you're running these tests, physically shake the xover. Loose components will cause noise, or go harmonic.
If that's all good double check your wiring. Make sure you've got the right leads going to the right places. On a three way like in the fEARfuls, I jumper from one input to the next board. That seems to be a sticking point for some folks. Make sure you have good strong mechanical connections. Loose connections will cause odd noises also.
If you want to test the crossover with a meter, you pretty much have to have one that will read capacitance. You can do basic tests with a standard meter, but the capacitors will block continuity. Best is to have one that reads inductance also, but that becomes another level of price The coils should show continuity, and that's usually good enough. When something blows, it's practically always the capacitors.
In my experience most of the time it's not the crossover. Wired wrong, something loose in the cab, vibration from hardware, all kinds of stuff. But it does happen. Patience is required to check this stuff out.
On the BigE front, I am just about ready to release demo cabs. Still have to work out my grille configuration. But the cabs are done, just awaiting hardware. And, AND, there's a new sub design I am building for the first time today. Previously to get all the really crazy vortex stuff you needed two cabs or two drivers in a cab. The evil geniuses have figured it out in a single driver for subs. If you saw the polar plot on my facebook page that's it. Tom described it as violent. It will come with a warning label and a hold harmless agreement. And that's not just marketing bullshit. :-)