I have been borrowing some of your crossover designs to try and improve my speakers which are used for mainly DJ use. I am using a Beyma 15G40 and PSD2002 in a vented box. I am using an Eminence PXB2:1k6 crossover.

I have created an lpad using two 15 ohm resistors and a 0.47uf cap for compensation. The resistors are wirewound and so may be inductive. See a pic below.

http://www.tuffer.co.uk/cross1.jpg

I have also disconnected one end of the 10uf cap on the crossover to give me a pseudo first order filter on the woofer.

http://www.tuffer.co.uk/cross2.jpg

Was quite happy with the results. Attenuation is perhaps a little strong. 8db might have been better.

On their first proper outing however both the fuses on the crossover board blew. They were being powered by a Behringer EP2500 so about 450w max to each cab. I wasn't present when they blew but was told that they weren't being driven particularly hard. I had been using these crossovers without the lpad or mod for some time without any problems.

Can anyone tell me if what I have done looks OK ? Could any of these changes increased the likelihood of overload and the fuses blowing or is it just one of those things that happen ? Should I just replace them with stock Eminence fuse or something else ? Obviously while the fuses have done there job and protected the HF drivers I wan't these cabs to be as reliable as possible.

Thanks for your help.

Excuse my ignorance but where would I check for a dead short or an open ? I have an ohmeter.

Thanks for your help.

Honestly, bulbs work better for tweeter protection than any fuse or breaker I've seen, as they compress the signal rather than fusing. The bulbs only blow if the signal is much higher than expected or if the load is open or shorted. I suggest that you get out a meter and start quantifying things. Check the voltage level of the amplifier when the bulbs blow. Those bulbs don't cost much, so it isn't any trouble to make a few tests that push them to the point of destruction. Also, check the impedance across the crossover's tweeter output. Check the voltage across the tweeter output. Once you know more about what's happening, you can make a more informed decision how to correct it.