[aktiondan]

Is anyone else using REW to design crossovers? I've been working on a new set of MTM speakers for a friend's home theater and discovered that REW works great for measuring crossover networks. To some degree it will even do impedance plots and measure Zobel networks. See the example below. Though I don't believe the absolute impedance value is correct (i.e., the graph shows the resonant frequency of the woofer [red] to be at 39Hz and a dB level that might correspond with an impedance of only 8.7 ohms, when in fact it's more like twice or three times that (you'd need to convert the log function to a linear function), however the profile of the curve is accurate). Notice the classic impedance rise which is easily combated with a simple Zobel network. Using just 15uF cap and 8 ohm resistor I was able to measure the transfer function [purple] of the Zobel (into an 8 ohm resistive load) and then see what the resultant impedance plot of the woofer [green] looks like - much better! (The black line is my reference, which is an 8 ohm resistive load). From here I can easily adjust the capacitor and resistor to tweak the profile and achieve something that looks even better.

Anyway, this also works for crossover networks, (I've got a bunch of plots of those, too) as well as measuring the near-field response of woofers and tweeters. So far I haven't seen any inherent limitation in REW that would indicate it isn't capable of doing these kinds of measurements (other than the proper scaling for impedance). But there is one thing I would love to see - the ability to export the graph to a .csv file. That way impedance plots and measured FR plots of drivers could be imported into Passive Crossover Designer 5.00 and then used for actually designing crossover networks (instead of relying on mfg's data) and then once the crossovers are designed, REW can be used to measure them and tweak them. And of course once the speaker is built, you can measure the resultant 20-20kHz response of whole speaker.

Just thought I'd share, REW has proved to be invaluable to me, and I am glad I ran across this site. Sorry this is my first post and kinda long, but this forum is great.