I'm sort of limping along here on Speaker Workshop until my copy of Sound Easy 8.00 arrives in a couple of weeks. I'm trying to design a relatively simple 2-way crossover for a friend of mine based on limited information using two 4 ohm Vifa 7" drivers in series, and a North Creek D25 tweeter. I tweaked with the values a lot to try and get a reasonable frequency response. I finally settled on a 2nd order network on the tweeter using a 2.5 uF cap bypassed with an 8 ohm resistor and a 0.2 mH coil, and a simple 1 mH choke on the Vifas. I also put into place a zobel on the woofers, with a 10 uF cap and an 8 ohm resistor.The result is a frequency response that appears to be +- 2db in the 86-90 db range, with the exception of a rise above 20 kHz, which I suspect is just a weird anomoly in the program.
Having said that, I really don't trust this software much and particularly in this case when it comes to having the two Vifas wired in series. I was also expecting a reference sensitivity more along the lines of 90-91 db, rather than the 88 or so I've managed to achieve. Also, the reverse phase null is a fairly deep 17db, but I'm not sure if it's deep enough to indicate a truly smooth phase transition
I just don't trust this program I guess... Maybe someone could reply here or e-mail me with some thoughts and suggestions, perhaps we could flesh things out a little more.
If anyone could offer their assistance (espcially Wayne!!!) I'd greatly appreciate it.
Thanks guys.
Adam