Has anyone built or simmed the cross over for the Mini-Elliptical driver that's on this site? I think there's a typo in the tweeter crossover - the 2.7 UF cap gives a very strange result when I sim it in PCD. It looks to me like the cap should be 27 uF or perhaps I made a PCD sim error. I attached the crossover and my sim. Regards, Ed Perkins
The crossover effect looks about right, but the tweeter's raw response looks off. I don't have PCD on the computer I'm on right now to look, but I don't think it rolled off that sharply, at either end.
I'm used my DATS to generate the .zma file: Re = 6.55 Ohm, 14.75 Ohm peak at 2.4 KHz (attached). What throws me off is the filter's response - it has a sharp peak just before rolloff (see my previous PCD screen shot) which I haven't seen before. Is this by design? I modeled the xover in Speaker Workshop and got the same results as PCD. I'll redo the driver's FR tonight - it does seem to drop off too much at the high end.
ernperkins, I've attached my zma and frd files. Your impedance plot looks a little different than mine. I have 2 more I these I haven't tested yet. I could. That would be 4 samples. My frequency response looks a little different to. The posted cross over looks to be similar than mine with fancier padding. 3rd order right around 3khz. Slightly different values in a different arrangement. I sorta used my filter to pad the tweeter output, so my caps are smaller that way.
Here's what I get with my files. Follows a BW4 pretty closely. A little difference likely from the baffle or woofer integration. Did you trace Bwaslo's plot? Might not have turned out. What are you using this tweeter for? I see you posted in my thread. Maybe we can help each other. I've attached my woofer files as well if you wanna take a crack at modelling my speaker. I could wire something up and see how it does too.
The difference is definitely in my .frd and to a lesser extent, my .zma files. I don't get the sharp drop out in the FR that you get. I'll try retesting. I'm using a 4 X 4 "infinite" baffle - are your measurements using the speaker baffle? Thanks, Ed PS - I'm currently working a different project, hence the time lag in my response.
Ya, my measurements are on an 8 x 12 baffle. I'm not sure that's it though. It's to much to be diffraction, and it doesn't change to much off axis. It could be though because there is some change. It coincides with the impedance spike though...
